10248 hanover park community bank geotechnical...

REPORT OF SUBSURFACE EXPLORATION AND GEOTECHNICAL ENGINEERING SERVICES

PROPOSED HANOVER PARK COMMUNITY BANK 6800 BARRINGTON ROAD HANOVER PARK, ILLINOIS

ECS PROJECT NO. 16:10248

FOR

GRUND & RIESTERER ARCHITECTS

SEPTEMBER 8, 2014

REPORT PROJECT

Subsurface Exploration and Geotechnical Engineering Services

Proposed Hanover Park Community Bank 6800 Barrington Road Hanover Park, Illinois

CLIENT

Mr. Jerry Cropsey Grund & Reisterer Architects

20 North Wacker Drive, Suite 2418 Chicago, Illinois 60606

SUBMITTED BY

ECS Midwest, LLC 1575 Barclay Boulevard

Buffalo Grove, Illinois 60089

Illinois Professional Design Firm No. 184-004247

PROJECT #16:10248

DATE September 8, 2014

TABLE OF CONTENTS EXECUTIVE SUMMARY

Page

PROJECT OVERVIEW 1

Introduction 1 Purposes of Exploration and Scope of Services 1

EXPLORATION PROCEDURES 3

Subsurface Exploration Procedures 3 Laboratory Testing Program 3

EXPLORATION RESULTS 5

Soil Conditions 5 Groundwater Observations 5

ANALYSIS AND RECOMMENDATIONS 7

Overview 7 Subgrade Preparation and Earthwork Operations 7 Fill Placement and Compaction 11 Foundation Recommendations 14 Floor Slab Design 16 Underslab Sub-Drainage Design 17 Exterior Pavement Design 17 Pavement Maintenance 19

PROJECT CONSTRUCTION RECOMMENDATIONS 21

General Construction Considerations 21 Foundation Subgrades 22 Construction Dewatering 22 Closing 23

APPENDIX 25

EXECUTIVE SUMMARY

The subsurface conditions encountered during our exploration and ECS Midwest, LLC.’s conclusions and recommendations are summarized below. This summary should not be considered apart from the entire text of the report with all the qualifications and considerations mentioned herein. Details of our conclusions and recommendations are discussed in the following sections and in the Appendix. The project site is located at the southeast corner of Barrington Road and Walnut Avenue in Hanover Park, Illinois. The project site is currently developed by an existing gas station. The proposed construction at the project site will consist demolishing the existing gas station and constructing a new bank. To better understand the subsurface conditions at the project site, five (5) soil borings, designated as B-1 through B-5, were drilled in the vicinity of the proposed site improvements to depths ranging from 7½ feet to 20 feet below existing site grades. The subsurface conditions encountered at the borings performed at the site can be summarized as follows. The surficial materials encountered at the boring locations were observed to consist of approximately 3 to 8 inches of bituminous material or approximately 10 inches of topsoil. Approximately 8 to 13 inches of gravel base was encountered below the bituminous material. The topsoil and bituminous material, where encountered at the boring locations, was underlain by SILTY CLAY FILL (CL/ML FILL) to a depth of approximately 3½ to 8½ feet below existing grades. The existing silty clay fill soils were generally dark brown and black and observed to contain trace amounts of asphalt and topsoil. At boring location B-1, black PEAT (PT) and greenish gray ORGANIC SOIL (OL/OH) deposits were encountered below the silty clay fill. The peat and organic soils were observed to extend to a depth of approximately 15 feet below existing grades. The Silty Clay FILL and organic soils (where encountered) were underlain by natural brown to gray SILTY CLAY (CL/ML) to the termination depths of the borings (7½ to 20 feet below existing grades). The natural silty clay was observed to transition from brown to gray at a depth of approximately 12 to 15 feet below existing site grades. The SILTY CLAY FILL soils were observed to exhibit stiff to hard consistency, with hand penetrometer values ranging from 1¼ to 4¼ tsf and moisture contents varying from 15 to 35 percent. The PEAT and underlying ORGANIC SOIL encountered at boring location B-1 was observed to be very soft to soft and determined to have moisture contents of 44 to 166 percent. The PEAT and ORGANIC SOIL had N-values of 1 to 5 blows per foot (bpf). The natural SILTY CLAY soils were observed to be stiff to hard in consistency exhibiting unconfined compressive strength values ranging from 1 to greater than 4½ tsf. The moisture contents of the natural SILTY CLAY soils were determined to range from about 17 to 31 percent (typically 17 to 23 percent). T The borings encountered undocumented Silty Clay FILL and/or Organic PEAT soils to as deep as approximately 5 to 15 feet below existing site grades underlain by natural stiff to hard Lean CLAY. Based on the subsurface conditions encountered at the site, provided history of the project site and our understanding of the proposed construction, ECS is providing the following three options for the proposed structure foundations. Option 1 consists of supporting the proposed structure on a shallow foundation system after removal and replacement of unsuitable fill soils. Option 2 consists of installation of helical piers. Option 3 consists of re-orientation of the proposed building. ECS strongly recommends that additional borings, probes or test pit exploration program be performed prior to final design to better delineate the limits of the deep deposits of variable fill soils at the site and specifically within the footprint of the proposed building and drive thru lane. A more economical option (construction cost perspective) for the proposed structure might be to relocate the building outside these areas with deep fill and organics, if feasible. More detailed recommendations with regard to foundations, subgrade preparation and earthwork operations, fill placement, slab and pavement design, underslab drainage and construction dewatering are included herein and must be fully reviewed and understood so that the intent of the recommendations are properly utilized during design and construction of the proposed development. We recommend that ECS be retained during construction of the proposed development to monitor all earthwork/subgrade preparation to verify that the exposed subgrade materials and the soil bearing pressures will be suitable for the proposed structure. Report Prepared By: Report Reviewed By: Michael T. Bronson, P.E. Brett Gitskin, P.E. Geotechnical Group Leader Senior Principal Engineer

PROJECT OVERVIEW Introduction This report presents the results of our subsurface exploration and geotechnical engineering recommendations for the proposed Hanover Park Community Bank to be located at 6800 Barrington Road in Hanover Park, Illinois. A General Location Map included in the Appendix of this report shows the approximate location of the project site. This study was conducted in general accordance with ECS Proposal No. 16:12732-GP (dated July 17, 2014) and authorized by you. In preparing this report, we have utilized information from our current subsurface exploration as well as information from nearby sites. Existing Site Conditions The project site is located southeast of the intersection of Barrington Road and Walnut Avenue in Hanover Park, Illinois. The site is bound to the north and west by undeveloped land, to the south by Walnut Avenue, and to the west by Barrington Road. The project site is currently developed by a Mobil gas station and convenience store. The RFP indicates a prior basement exists at the site. Our review of the survey drawing indicates existing site grade will range from approximately EL. +807 feet to EL. +809 feet +/-. Proposed Construction Based on the information provided to ECS, we understand the proposed construction at the project site will consist of a bank building which includes a drive through and the associated amenities (i.e., canopy, drive lanes, and a parking lot). The proposed structure is anticipated to be slab-on-grade, single-story with no below-grade levels. The proposed building will house an approximately 6,400 SF bank. The building will be flanked to the west by drive through lanes, to the north by parking lots, by the south by Walnut Avenue to the east by Barrington Road. The RFP indicates a basement from a prior building exists on site. A portion of the proposed construction/building will be constructed over the existing USTs (after removal). Typical column and wall loads will be in the range of 40 to 50 kips and 2 to 2½ klf, respectively, based on the information provided to us from the request for proposal. The walls will be light structure with 4 inch face brick. The drive through area will have structural portal frames and light gauge roof trusses with metal decking. A pre-existing basement on site will need to be filled. Purposes of Exploration and Scope of Services The purposes of this exploration were to explore the soil and groundwater conditions at the project site and to develop engineering recommendations to guide in the design and construction of the project. We accomplished these purposes by performing the following scope of services:

ECS Project No. 16:10248 -2- September 8, 2014 Proposed Hanover Park Community Bank Hanover Park, Illinois

1. Reviewing the geotechnical reports prepared for nearby sites by ECS;

2. Drilling five (5) SPT (standard penetration tests) soil borings at the project site using an auger drill rig;

3. Performing laboratory tests on selected representative samples from the borings to evaluate pertinent engineering properties;

4. Analyzing the field and laboratory data to develop appropriate engineering recommendations; and,

5. Preparing this geotechnical report of our findings and recommendations. The conclusions and recommendations contained in this report are based on five (5) soil borings, designated as B-1 through B-5, conducted at the project site under ECS’ direction. The soil borings were drilled to a depth of 7½ to 20 feet below existing site grades. The subsurface exploration included split-spoon soil sampling, standard penetration tests (SPT) and groundwater level observations in the boreholes. The results of the completed soil borings, along with a Boring Location Plan are included in the Appendix of this report. The boring locations were selected by ECS based on the proposed layout of the proposed construction. The borings were located in the field by an ECS representative. The approximate locations of the borings are shown on the Boring Location Plan. Based on our review of the provided survey plan, the existing topography at the site is generally flat with ground elevations ranging from approximately EL. +807 feet to EL. +809 feet +/-. .


EXPLORATION PROCEDURES Subsurface Exploration Procedures The borings were located in the field by an ECS representative. The soils borings were selected based on the proposed layout of the proposed construction. An ECS subcontracted driller contacted the State of Illinois Utility One-Call Center, JULIE, to clear and mark underground utilities in the vicinity of the project site prior to drilling operations. The soil borings were performed with a CME 45 truck-mounted rotary-type auger drill rig which utilized continuous flight augers to advance the boreholes. Representative soil samples were obtained by means of conventional split-barrel sampling procedures. Samples were typically obtained at 2½-foot intervals in the upper 10 feet and at 5-foot intervals thereafter. In this procedure, a 2-inch O.D., split-barrel sampler is driven into the soil a distance of 18 inches by a 140-pound hammer falling 30 inches. The number of blows required to drive the sampler through a 12-inch interval, after initial setting of 6 inches, is termed the Standard Penetration Test (SPT) or N-value and is indicated for each sample on the boring logs. The SPT value can be used as a qualitative indication of the in-place relative density of cohesionless soils. In a less reliable way, it also indicates the consistency of cohesive soils. This indication is qualitative, since many factors can significantly affect the standard penetration resistance value and prevent a direct correlation between drill crews, drill rigs, drilling procedures, and hammer-rod-sampler assemblies. The drill rig utilized an automatic trip hammer to drive the sampler. Consideration of the effect of the automatic hammer’s efficiency was included in the interpretation of subsurface information for the analyses prepared for this report. A field log of the soils encountered in the borings was maintained by the drill crew. After recovery, each geotechnical soil sample was removed from the sampler and visually classified. Representative portions of each soil sample were then sealed in jars. The soil samples were then delivered to our laboratory in Buffalo Grove, Illinois for further visual examination and laboratory testing. After completion of the drilling operations, the boreholes were backfilled with auger cuttings to the existing ground surface. Laboratory Testing Program Representative soil samples were selected and tested in our laboratory to check field classifications and to determine estimate engineering properties. The laboratory testing program included visual classifications, calibrated hand penetrometer unconfined compressive strength testing and moisture content determinations of cohesive soil samples. Each soil sample was classified on the basis of texture and plasticity in accordance with the Unified Soil Classification System. The group symbols for each soil type are indicated in parentheses following the soil descriptions on the boring logs. A brief explanation of the Unified System is included with this report. The various soil types were grouped into the major zones noted on the boring logs. The stratification lines designating the interfaces between earth materials on the boring logs and profiles are approximate; in situ, the transitions may be gradual.


The unconfined compressive strength (Qp) of relatively cohesive clay soil samples was estimated with the use of a calibrated hand penetrometer. In the hand penetrometer test, the unconfined compressive strength of a soil sample is estimated, to a maximum of 4½ tons per square foot (tsf) by measuring the resistance of a soil sample to penetration of a small, calibrated spring-loaded cylinder. The soil samples will be retained in our laboratory for a period of 60 days, after which, they will be discarded unless other instructions are received as to their disposal.


EXPLORATION RESULTS Soil Conditions Five (5) soil borings, designated as B-1 through B-5, were performed for this project. The soil borings were drilled to a depth of 7½ to 20 feet below existing site grades. The subsurface conditions encountered at the borings performed at the site can be summarized below. The specific soil types observed at the boring locations are noted on the boring logs enclosed in the Appendix. The ground elevations noted on the logs were existing grades at the time of our subsurface exploration. The surficial materials encountered at the boring locations were observed to consist of approximately 3 to 8 inches of bituminous material or approximately 10 inches of topsoil. Approximately 8 to 13 inches of gravel base was encountered below the bituminous material. The topsoil and bituminous material, where encountered at the boring locations, was underlain by SILTY CLAY FILL (CL/ML FILL) to a depth of approximately 3½ to 8½ feet below existing grades. The existing silty clay fill soils were generally dark brown and black and observed to contain trace amounts of asphalt and topsoil. At boring location B-1, black PEAT (PT) and greenish gray ORGANIC SOIL (OL/OH) deposits were encountered below the silty clay fill. The peat and organic soils were observed to extend to a depth of approximately 15 feet below existing grades. The Silty Clay FILL and organic soils (where encountered) were underlain by natural brown to gray SILTY CLAY (CL/ML) to the termination depths of the borings (7½ to 20 feet below existing grades). The natural silty clay was observed to transition from brown to gray at a depth of approximately 12 to 15 feet below existing site grades. The natural SILTY CLAY encountered at boring location B-5 at a depth of 3½ to 7½ feet (termination of the boring) was noted to exhibit a petrochemical odor. Evaluating the source of the petrochemical odor and the limits of the soils that exhibit the odor was beyond the scope of the geotechnical engineering study. Boring B-5 was drilled southeast of the underground storage tank(s) reportedly located on the southwestern side of the existing building at the project site. The SILTY CLAY FILL soils were observed to exhibit stiff to hard consistency, with hand penetrometer values ranging from 1¼ to 4¼ tsf and moisture contents varying from 15 to 35 percent. The PEAT and underlying ORGANIC SOIL encountered at boring location B-1 was observed to be very soft to soft and determined to have moisture contents of 44 to 166 percent. The PEAT and ORGANIC SOIL had N-values of 1 to 5 blows per foot (bpf). The natural SILTY CLAY soils were observed to be stiff to hard in consistency exhibiting unconfined compressive strength values ranging from 1 to greater than 4½ tsf. The moisture contents of the natural SILTY CLAY soils were determined to range from about 17 to 31 percent (typically 17 to 23 percent). The higher moisture contents of 27 to 31 percent were determined from the natural SILTY CLAY encountered below the silty clay fill at boring location B-5, where a petrochemical odor was noted as mentioned earlier.

Groundwater Observations Observations for groundwater were made during sampling and upon completion of the drilling operations at the boring locations. In drilling operations, water is not introduced into the


boreholes, and the groundwater position can often be obtained by observing water flowing into or out of the boreholes. Furthermore, visual observation of the soil samples retrieved during the auger drilling exploration can often be used in evaluating the groundwater conditions. Groundwater seepage was encountered at a depth of about 2½ to 8 feet below existing grade at boring location B-3 and at a depth of approximately 17½ to 18 feet below existing grades at boring location B-4. Groundwater was not encountered at the remaining boring locations. Glacial till soils in the Midwest frequently oxidize from gray to brown above the level at which the soil remains saturated. The long-term groundwater level is often interpreted to be near this zone of color change. Based on the results of this exploration and soil color change, the static long-term groundwater level at the project site is estimated to be located at a depth of approximately 10 to 12 feet below existing site grades (i.e., EL. +796 to EL. +798 above mean sea level). We believe the groundwater seepage encountered at boring location B-3 at a depth of about 2½ to 8 feet below existing grade could be a perched water condition. Perched water occurs as rainfall or overland drainage that has infiltrated the pavement through pavement cracks or openings collects, or becomes perched on less permeable soil as it percolates downward, and is typically a transient condition associated with rainfall. The highest groundwater observations are normally encountered in late winter and early spring and our current groundwater observations are not expected to be at the seasonal maximum water table. It should be noted that the groundwater level can vary based on precipitation, evaporation, surface run-off and other factors not immediately apparent at the time of this exploration. Surface water runoff will be a factor during general construction, and steps should be taken during construction to control surface water runoff and to remove any water that may accumulate in the proposed excavations as well as pavement/slab areas.


ANALYSIS AND RECOMMENDATIONS Overview The conclusions and recommendations presented in this report should be incorporated in the design and construction of the project to reduce possible soil and/or foundation related problems. The following recommendations have been developed on the basis of the previously described project characteristics and subsurface conditions encountered at the project site. If there are any changes to the project characteristics or if different subsurface conditions are encountered during construction, ECS Midwest, LLC should be consulted so that the recommendations of this report can be reviewed and modified, if necessary. The following sections present specific recommendations with regard to the design of the proposed Hanover Park Community Bank. These include recommendations with regard to subgrade preparation and earthwork, fill placement, building foundations, floor slab design, pavement design and construction dewatering. Discussion of the factors affecting the building foundations for the proposed construction, as well as additional recommendations regarding design and construction at the project site are included below. We recommend that ECS review the final design and specifications to check that the earthwork and foundation recommendations presented in this report have been properly interpreted and implemented in the design and specifications. Subgrade Preparation and Earthwork Operations The proposed building will be one-story, of slab-on-grade construction and will not include a basement level. The building footprint will be located in the vicinity of the existing gas station facility to be demolished. A portion of the structure will also be placed in vicinity of the existing underground storage tanks associated with the gas station which will be removed prior to construction. Based upon the existing topography across the site (i.e., relatively level), we have assumed the building finish floor elevation will approximately match the existing site grades. If our assumption for the final grade is incorrect, or if existing grades will be raised, please contact ECS so we can review (and revise if appropriate) our recommendations for subgrade preparation discussed below. Existing Building Demolition/Backfilling The existing structures will be demolished as part of the proposed development. To limit the potential for future settlement of the proposed structure, it is critical that the existing structures be properly demolished and backfilled prior to construction of the new project structure. Improper demolition and backfilling could lead to foundation and floor slab/pavement distress caused by unacceptable total and differential settlements. The existing structures (i.e., slabs, foundation walls/footings and any below-grade walls/slabs/foundations and underground structures) should be completely removed during demolition activities and backfilled with compacted engineered fill to the final design site grades. It has been our experience that many demolition contractors place the debris in excavations from the structure and cap with soil. These types of activities will not provide a suitable subgrade for foundations, slabs or pavements. The foundation contractor should mobilize appropriate equipment to remove and/or


break up existing foundations and other obstructions without delay. All underground utilities to remain should be positively located, properly protected and supported prior to and during excavation and subgrade preparation activities. Underground utilities within the proposed building areas should be relocated or removed and backfilled with engineered fill. We recommend engineered fill consisting of crushed granular material (preferably IDOT CA-6) be considered to backfill excavations resulting from demolition of the existing structures and removal of underground utilities. Abandoned utilities should be grouted in place. We understand either the existing building or another former building contained a basement. It is imperative that this basement is completely backfilled with engineered fill. Undocumented existing backfill materials are likely to be encountered around existing structures and underground utilities (i.e. backfill materials around foundations, against below-grade walls and existing utility trenches). We recommend undocumented existing fill materials encountered during removal of existing construction be removed and replaced with new engineered fill. Existing backfill material that is found suitable for re-use as engineered fill (upon evaluation and approval by ECS at the time of demolition/excavation) can be placed back and compacted in lifts in accordance with the Fill Placement and Compaction section. New construction bearing on undocumented existing variable fill could result in unfavorable total and differential settlements and structure distress. As such, it is important existing undocumented fill materials should not be left in place and should be removed or replaced or recompacted. ECS highly recommends that the demolition and backfilling operations at the project site be observed by an ECS field representative retained on your behalf to confirm and document that work is performed in general accordance with the recommendations detailed herein and the backfill materials used are approved materials and adequately placed and compacted, especially in the basement and UST excavations. Subgrade Preparation – New Building Floor Slab and Pavement Areas In new building slab and pavement areas to be located within the existing buildings to be demolished, it is important that all excavations resulting from demolition of existing buildings (i.e., removal of existing foundations, slabs-on-grade, and any below-grade walls/slabs and underground structures) should be backfilled with engineered fill as recommended in the Existing Building Demolition/Backfilling section of this report. The existing structures should be properly demolished and engineered fill materials used to backfill excavation areas should be properly placed, compacted and documented prior to construction of the new project structure. For the portions of the site beyond the limits of the existing building that are going to be developed for the new structure and pavements, initial subgrade preparation for the new building pad and exterior pavements should consist of complete removal of existing pavements, topsoil, base materials, unsuitable fill and other deleterious organic or refuse material. Once the surficial materials have been removed, the limits of the proposed building, parking lot and drives should be excavated to the design subgrade elevations. ECS does not recommend that the subgrade remain exposed to the elements or construction traffic for a prolonged period of time as the subgrade may be disturbed and/or softened. If the pavement and/or slab section is not planned to be constructed within a few days after exposing the final design subgrade, consideration should be given to leaving the subgrade approximately 1 foot above the final design subgrade to help prevent softening of the design subgrade soils (if feasible).


We anticipate the subgrade soils beneath the new floor slab areas will consist of undocumented existing Clay FILL soils and/or new engineered fill materials used to backfill excavations resulting from existing structure demolition. We typically do not recommend slabs/pavements be supported on or above undocumented fill materials as the fill materials exhibit variable composition, moisture contents and in-situ relative densities, which could result in unfavorable total and differential settlements and premature deterioration/ cracking of the slab/pavement. In addition, the existing deep fill soils on site appeared to have been used or to backfill old UST excavations (B-3) which can settle over time when subjected to new foundation, slab and/or traffic loads. We are also aware that complete removal and replacement of the existing FILL soils may not be feasible from a slab/pavement construction cost perspective. As such, consideration could be given to leaving the existing Caly FILL soils in place underneath the floor slabs/pavements provided the following: (1) the subgrade passes a proofroll and (2) the owner is willing to accept some risk of premature deterioration of the slabs/pavements and long term maintenance issues related to compression of the variable fill soils. In addition to existing fill, a layer or Organic CLAY and/or Organic PEAT was observed at boring location B-1 and CLAY FILL with Topsoil at boring location B-3. These soils have elevated moisture contents and are highly compressible. ECS recommend consideration be given to completely removing the Organic/Topsoil CLAY and PEAT prior to construction to reduce the risk of unfavorable settlement of pavements or structure. If complete removal and replacement of the PEAT and Organic Clay/Clay FILL with Topsoil is not feasible ECS recommends existing site grades not be raised or lowered, if possible of pavements or structure. To better delineate the limits of the FILL and PEAT soils within the limits of the proposed building, we recommend additional borings, probes or test pit exploration program be performed prior to mass grading activities and/or prior to bidding. Consideration can be given to performing the test pit exploration program concurrently during the demolition phase of the project which we understand is imminent. The subgrade issues associated with unsuitable undocumented fill soils can be addressed and remedied (i.e., removal and replacement) at the same time as backfilling operations of excavations resulting from demolition of existing structures are performed. If no test pit exploration program is performed prior to mass grading activities and/or prior to bidding, we recommend test pits be performed prior to construction to identify buried unsuitable existing fill and/or PEAT soils at the site and the contractor should be prepared to remove and replace buried unsuitable existing fill or PEAT and organic soils without delay. The test pit exploration and remedial activities should be observed and documented by an ECS field representative.

Proofrolling Once the subgrade has been exposed and prior to placing new fill and base material, the subgrade should be proofrolled using a loaded dump truck having an axle weight of at least 10 tons. The intent of the proofroll is to aid in identifying localized soft or unsuitable material which may be required to be removed. If soft or yielding soils are observed during the proofroll of the subgrade, the soft or yielding soils should be undercut up to a maximum of 2 feet and replaced with compacted and engineered fill to the design subgrade in accordance with the Fill Placement section of this report. Proofrolling of the subgrade should be performed under the observation of an ECS field representative.


To help limit the volume of soil removed as a result of the proofrolling observations, we recommend that soft or yielding soils be evaluated in approximately 6 to 12-inch intervals. That is to say, if soft or yielding soils are identified, the contractor should remove 6 to 12 inches of material in the subject area and then proofroll/evaluate the undercut subgrade. This will potentially limit the need to remove 2 feet of soil at once at all locations where soft or yielding soils are identified. A DCP (dynamic cone penetrometer) can also be used in conjunction with proofrolling to establish appropriate depths for remedial action. Subgrade Preparation - Building Foundations For building foundations, we do not recommend the footings bear on or above existing fill, organic soils or PEAT soils. For subgrade preparation of the building foundations, please refer to the section entitled Foundation Recommendations of this report. Subgrade Preparation - General We recommend site/subgrade preparation including demolition of existing structures, removal of pavements, USTs, topsoil and backfilling operations should be observed on a full-time basis by an ECS field representative to determine all unsuitable/deleterious soils/materials are being removed and the specified backfill and compaction requirements are being met. Because of the need to demolish the existing structure and remove the USTs and the presence of undocumented FILL/Organics/PEAT, deeper undercuts or removal and replacement due to soft/loose soils and other weak/unsuitable soils should be anticipated during subgrade preparation. We recommend appropriate contingencies be included in construction budgets to cover the cost of removal and replacement of weak/unsuitable and soft/loose soils if encountered at various locations, especially in UST areas, existing gas station facility areas, prior basements and areas with deep organic/PEAT deposits. The earthwork operations and subgrade preparation should be monitored by an ECS field representative to make sure unsuitable soils and other deleterious material is stripped. Steps should be taken by the contractor to control surface water runoff and to remove water from precipitation that may accumulate in the subgrade areas, especially during the wet season. Exposure to the environment may weaken the subgrade soils if the excavations remain open for too long a period. If the subgrade soils are softened by surface water intrusion or exposure, the softened soils must be removed from the subgrade excavation bottom immediately prior to placement of pavement, concrete and/or engineered fill. The need for and most appropriate type of stabilization required will be dependent upon soil, groundwater and weather conditions, as well as, the construction schedule and methods of construction that will be used. In general, scarifying, drying and recompacting moderately unstable soil areas is expected to be the most economical means of improving the poor and high moisture content soils prior to final preparation of building pad and pavement subgrades. The best period for air drying soils typically occurs in dry times of the year (i.e., summer), and the warm weather experienced in the summer months usually is more conducive to dry site conditions. Alternatives for subgrade stabilization could also include undercutting and replacing


unsuitable soils as recommended herein. The use of geotextile as a separator and geogrid along with aggregate fill can also be considered to stabilize the subgrade. We recommend the need for a geogrid reinforced subgrade be evaluated at the time of construction if significant unstable/unsuitable soils are encountered. If geogrid is considered, we recommend tri-axial geogrid (similar to Tensar TX160) be used. The geogrid should be placed such that it interlocks with the aggregate fill. Existing FILL soils such as Clayey Sand and Gravel FILL, Silty Sand FILL and Fine Sand FILL with clay and silt are difficult to work with and compact, especially when wet. If these (Clayey Sand and Gravel FILL, Silty Sand FILL and Fine Sand FILL with clay and silt) soils are encountered at the slab/pavement subgrade elevation during subgrade preparation, removal and replacement and/or subgrade stabilization should be anticipated. Excavations should comply with the requirements of OSHA 29CFR, Part 1926, Subpart P, "Excavations" and its appendices, as well as other applicable codes. This document states that the contractor is solely responsible for the design and construction of stable, temporary excavations. The excavations should not only be in accordance with current OSHA excavation and trench safety standards but also with applicable local, state, and federal regulations. The contractor should shore, slope or bench the excavation sides when appropriate. If problems are encountered during the earthwork operations, or if site conditions deviate from those encountered during our subsurface exploration, ECS should be notified immediately. We recommend that an ECS field representative should be on site to monitor stripping and site preparation operations and observe that unsuitable soils have been satisfactorily removed and observe the proofrolling of the subgrades. Fill Placement and Compaction All fills should consist of an approved material, free of organic matter and debris, particles greater than 3-inches and have a Liquid Limit and Plasticity Index less than 40 and 15, respectively. Unacceptable fill materials include topsoil and organic materials (OH, OL), high plasticity silts and clays (CH, MH), fat clays and low-plasticity silts (ML). Under no circumstances should high plasticity soils be used as fill material in proposed structural areas or close to site slopes. We do not recommend the use of pea gravel as engineered fill. Pea gravel has round/smooth characteristics, no fines and does not interlock when compacted which make more susceptible to future movement and instability resulting in excessive and variable settlement. If the existing subgrade will be cut, the surficial crushed aggregate materials can be stockpiled for later use as engineered fill on site. In general, existing Silty Clay Fill soils without organics/topsoil and other deleterious materials can be utilized as engineered fill. The existing Clay FILL without organics may require moisture conditioning prior to being utilized as engineered FILL. Topsoil should not be used beneath structural areas but can be utilized for landscaping purposes. For on-site soils found suitable (after ECS’ evaluation during construction) for use as engineered fill, the contractor should be prepared to implement discing or other drying techniques (termed manipulation) and recognize and account for increased costs associated with manipulation of the suitable on-site soils. Any on-site and off-site soils to be considered for


engineered fill at the project site should be approved by the project geotechnical engineer prior to placement at the time of construction. Fill materials should be placed in lifts not exceeding 8-inches in loose thickness and moisture conditioned to within ±2 percentage points of the optimum moisture content. Soil bridging lifts should not be used, since intolerable settlement of overlying structures will likely occur. Controlled fill soils should be compacted to a minimum of 95% of the maximum dry density obtained in accordance with ASTM D-1557, modified Proctor method. The zone of the engineered fill placed below the foundations should extend 1 foot beyond the outside edges of the footings and from that point, outward laterally 1 foot for every 2 feet of fill thickness below the footing. The expanded footprint of the proposed building pad, pavement and fill areas should be well defined, including the limits of the fill zones at the time of fill placement. Grade control should be maintained throughout the fill placement operations. All fill operations should be observed on a full-time basis by a qualified soil technician to determine that the specified compaction requirements are being met. A minimum of one compaction test per 2,500 square foot area should be tested in each lift placed. Within trench or other localized excavations, one test for each 50 linear feet of each lift of fill shall be performed. The elevation and location of the tests should be clearly identified at the time of fill placement. Compaction equipment suitable to the soil type used as fill should be used to compact the fill material. Theoretically, any equipment type can be used as long as the required density is achieved; however, the standard of practice typically dictates that a vibratory roller be utilized for compaction of granular soils and a sheepsfoot roller be utilized for compaction of cohesive soils. In addition, a steel drum roller is typically most efficient for compacting and sealing the surface soils. All areas receiving fill should be graded to facilitate positive drainage away from the building pad and pavement areas. It should be noted that prior to the commencement of fill operations and/or utilization of off-site borrow materials, the Geotechnical Engineer of Record should be provided with representative samples to determine the material’s suitability for use in a controlled compacted fill and to develop moisture-density relationships. In order to expedite the earthwork operations, if off-site borrow materials are required, it is recommended they consist of suitable fill materials in accordance with the recommendations previously outlined in this section. Fill materials should not be placed on frozen soils or frost-heaved soils and/or soils that have been recently subjected to precipitation. All frozen soils should be removed prior to continuation of fill operations. Borrow fill materials, if required, should not contain frozen materials at the time of placement. All frost-heaved soils should be removed prior to placement of controlled, compacted fill, granular subbase materials, foundation or slab concrete, and asphalt pavement materials. Open-Graded Fill Materials ECS recommends engineered fill materials used to replace soft/loose soils and other weak/unsuitable soils and raise grades should consist of crushed aggregate materials similar to IDOT CA-6 or low plasticity lean clay soils. ECS understands site conditions or project


constraints occur where the use of crushed 3-inch rock (CA-1 or crushed CA-18/IDOT PGE) is recommended by the Contractor as substitution for engineered fill. Upon approval by ECS, CA-1 or CA-18/IDOT PGE may only be used if properly documented and witnessed by an experienced ECS Geotechnical engineer or qualified ECS representative. The contractor shall provide ECS with their means and methods for placement and densification of the open-graded fill materials to obtain ECS’ approval. The installation must be observed by an ECS representative full-time during placement operations. ECS encourages the placement of a minimum 8 ounce, non-woven geotextile fabric as a separator between the open-graded material and the native subgrade. The geotextile material reduces the potential for intermixing of the subgrade soils with the open-graded aggregate and potential settlement. As mentioned earlier, pea gravel should not be used as engineered fill. If 3-inch rock (open graded granular fill, CA-1 or IDOT PGE) is to be considered for use as backfill, the 3-inch rock should be placed in accordance with the guidelines described herein. Due to the large diameter and absence of fines, 3-inch rock exhibits large voids. Fill materials containing large voids are more susceptible to future movement and may become unstable, resulting in excessive, unpredictable and variable total and differential settlement. These open-graded aggregates can not be tested using conventional density testing methods and therefore do not meet the definition of engineered fill as described elsewhere in this report. Proper placement of the open-graded material is typically achieved by using a smooth drum vibratory roller, “hoe pac” or backhoe bucket techniques wherein the operator applies energy to the open-graded aggregate until the stone “closes up” and interlock is observed. Due to the inability to utilize conventional compaction testing methods; an ECS engineer or qualified ECS representative should observe the material placed in lifts less than 12 inches in loose thickness, that the material is “closed up” (interlocked and stable), and under significant load no further densification or shifting occurs. Oversized fragments (greater than 3 inches in diameter) should be rejected and pulled from the fill. We recommend applying a sufficient number of passes with heavy vibratory steel wheel roller (minimum weight of 10,000 pounds), “hoe pac” or a sufficient number of impacts with a backhoe bucket to achieve interlock and a stable material. If deemed necessary by ECS, more energy may need to be applied after the contractor’s selected method of compaction. A “choking layer” at least 8 inches in thickness of CA-6 or similar materials (including a geotextile separator fabric as described above) should be placed on top of the 3-inch rock, at the final subgrade elevation. Deep Fill Considerations Extensive new fill placement (i.e., fill depths greater than 8 feet) is anticipated if the unsuitable fill or organic soils are completely removed. For extensive new fill placement, self-weight compression of the new fill soils should be considered. Even properly placed and compacted fill or new engineered fill soils, placed and compacted as discussed in the Fill Placement section of this report, will experience self-weight compression. In most cases, the amount of self-weight compression is negligible. However, when fill heights exceed about 8 feet, the magnitude of self-weight compression can adversely affect the performance of new grade supported construction. If the amount of fill to be placed beneath building foundations and slabs will be greater than 8 feet, we recommend consideration be given to using granular engineered fill to help minimize the effects of self-weight compression.


Foundation Recommendations The borings encountered undocumented Silty Clay FILL and/or Organic PEAT soils to as deep as approximately 5 to 15 feet below existing site grades underlain by natural stiff to hard Lean CLAY. Based on the subsurface conditions encountered at the site, provided history of the project site and our understanding of the proposed construction, ECS is providing the following three options for the proposed structure foundations. Option 1 consists of supporting the proposed structure on a shallow foundation system after removal and replacement of unsuitable fill soils. Option 2 consists of installation of helical piers. Option 3 consists of re-orientation of the proposed building. ECS strongly recommends that additional borings, probes or test pit exploration program be performed prior to final design to better delineate the limits of the deep deposits of variable fill soils at the site and specifically within the footprint of the proposed building and drive thru lane. A more economical option (construction cost perspective) for the proposed structure might be to relocate the building outside these areas with deep fill and organics, if feasible. As mentioned in the Subgrade Preparation and Earthwork Operations section of this report, consideration can be given to performing the test pit exploration program concurrently during the demolition phase of the project. Based on the results of the borings (i.e., boring B-1), existing fill and/or organics and peat is deeper at the northwest corner of the proposed building. The test pits or borings/probing should be performed starting in the vicinity of boring B-1 and move in select directions until adequate information regarding the vertical and lateral extents of the deep fill deposit is obtained. We recommended the proposed building layout be surveyed and corners staked prior to probing or performing the test pits. Option 1 - Removal and Replacement of Undocumented Variable Fill Soils The proposed structure can be supported on shallow foundations bearing on competent natural soils (stiff to hard Silty CLAY) or new engineered fill overlying competent natural soils. We do not recommend the footings bear on or above existing undocumented fill soils or the PEAT or organic materials. Existing undocumented fill and organic soils should be completely removed beneath all proposed foundations such that the footings bear on competent natural soils or on engineered fill used to replace unsuitable existing fill materials. A shallow foundation system bearing on competent natural soils (Silty CLAY) or new engineered fill (observed and tested by ECS) overlying competent natural soils can be designed for a net allowable bearing pressure of 3,000 psf. The net allowable soil bearing pressure refers to that pressure which may be transmitted to the foundation bearing soils in excess of the final minimum surrounding overburden pressure. Competent soils can be identified on the boring logs as natural Silty CLAY having calibrated hand penetrometer (Qp) values of 1½ tsf or greater. If the existing undocumented fill below the slab is not completely to be removed and replaced, the shallow foundation excavations will still have to extend completely through the existing fill to encounter competent natural Silty CLAY soils. The corresponding depths of foundation over-excavation may range to depths of about 5 to 6 feet below existing grades at boring locations


B-2 and B-4, respectively and to depths of 8 to 15 feet below existing site grades at boring locations B-3 and B-1, respectively. As an alternative to complete removal and replacement where deep existing fill soils are encountered (i.e., at boring location B-4 and other areas that maybe revealed through test pit exploration program), helical piers discussed in Option 2 can be considered. Again, we recommend additional test pit exploration program be performed to better delineate the lateral and vertical limits of the variable fill soils that needs to be removed and replaced or remediated within the limits of the proposed building. During project construction, we recommend that visual soil classification by an ECS representative supplemented with hand auger probes and/or DCP testing be performed to a depth below the foundation subgrade equivalent to ½ the footing width (i.e., ½ B), or a minimum of 5 feet below each isolated column footing and continuous footings. Visual soil classification supplemented with hand auger probes and/or DCP testing should be performed at each column footing and at approximately 20-foot intervals along continuous footings to verify the suitability of the soils to support the recommended maximum net allowable bearing pressure. We recommend crushed granular engineered fill (preferably crushed aggregate similar to IDOT CA-6) be used to backfill undercuts beneath the footings. The engineered fill should be compacted to a minimum of 95% of the maximum dry density in accordance with modified Proctor method, ASTM D 1557. The zone of the engineered fill placed below the foundations should extend 1 foot beyond the outside edges of the footings and from that point, outward laterally 1 foot for every 2 feet of fill thickness below the footing. If lean concrete is utilized to replace weaker/low bearing soils or unsuitable soils, no lateral over-excavation will be necessary, but the excavation should be 1 foot wider than the footing (6 inches on each side), and the lean concrete should be allowed to harden prior to placement of the footing concrete. We recommend that the excavation/backfill of foundations be monitored full-time by an ECS geotechnical engineer or his representative to verify that the soil bearing pressure is consistent with the boring information obtained during the geotechnical exploration. In areas where individual footings are founded at different elevations, it is important to provide a minimum slope of 1H:1V between the bottom edge of each foundation at their closest point. Care must be taken during excavation for new footings to prevent undermining of adjacent existing construction (i.e., sidewalk, pavements and utilities). Any excavation below the adjacent existing pavement, sidewalks and underground utilities should consider appropriate preventative measures, such as underpinning, to avoid undermining or loss of materials from beneath pavements, sidewalks and utilities. Footings should be placed at a depth to provide adequate frost cover protection. We recommend the exterior footings and footings beneath unheated areas be placed at a minimum depth of 3½ feet below finished grade. Interior footings in heated areas can be placed at a minimum of 2 feet below grade provided suitable soils are encountered and that the foundations will not be subjected to freezing weather either during or after construction. Please note new footings should extend below the existing fill and bear on competent natural Lean CLAY or on new engineered fill used to replace weak/unsuitable existing fill/buried topsoil and raise foundation subgrades. To reduce the potential for foundation bearing failure and excessive settlement due to local shear or "punching" action, we recommend continuous footings have a minimum width of 18 inches and that isolated column footings have a minimum lateral dimension of 30 inches.


Settlement of individual footings, designed in accordance with our recommendations presented in this report, is expected to be small and within tolerable limits for the proposed anticipated building. For footings placed on competent natural soils or properly compacted engineered fill overlying competent natural soils, maximum total settlement is expected to be in the range of 1 inch or less. Maximum differential settlement between adjacent columns is expected to be one-half the total settlement. These settlement values are based on our engineering experience and the anticipated structural loading, and are to help guide the structural engineer with his design. Option 2 - Steel Helical Piers Alternatively in areas where deep fill soils are encountered, the use of helical piers can also be considered to transfer the structure loads to the suitable natural soils. Helical piers should extend through the existing fill soils into competent, natural soils. Estimates of pier capacity are usually prepared utilizing proprietary bearing capacity methods unique to the pier manufacturers and the various pier configurations. Our previous experience suggests the helical pier foundation manufacturer will interpret the available subsurface information and provide appropriate foundations based upon proprietary design criteria. Typical capacities of steel helical piers are about 20 to 40 kips. The spacing and configurations of steel helical piers will depend on the actual foundation loads and reinforcement but typically 5 to 6 feet on center. Helical piers will likely extend to depths ranging from 10 feet to 20 feet below existing site grades. Option 3 Another option that the project team/owner can consider would be re-orienting the location of the proposed building and drive lanes which will be based upon the results of the additional test pit exploration program (i.e., vertical and lateral extents of the existing deep fill/peat deposits) and information pertaining to the location of the former UST and old house at the site. If feasible, the proposed building can be moved such that removal and replacement of unsuitable existing fill is eliminated or minimized within the building footprint to construct a more economical shallow foundation system and minimize traffic flow over the areas with Peat. Other deep foundation options such as drilled shafts or driven piles may also be considered. Our initial review indicates these options would not be cost effective. If the owner would like to revisit any of these alternate deep foundation solutions, please let us know. Floor Slab Design For the design and construction of the slabs-on-grade for the building, the recommendations provided in the section entitled Subgrade Preparation and Earthwork Operations should be followed. The building floor slab thickness can be determined utilizing an assumed modulus of subgrade reaction of 100 pounds per cubic inch (pci). If the existing undocumented fill soils are completely be removed and replaced, a modulus of subgrade reaction of 150 pci can be used in slab design. We recommend the slab be designed with a minimum thickness of 5 inches.


We recommend consideration be given to the floor slab being underlain by a minimum of 6 inches of granular material having a maximum aggregate size of 1½ inches and no more than 2 percent soil passing the No. 200 sieve. This granular layer will facilitate the fine grading of the subgrade and help prevent the rise of water through the floor slab. Prior to placing the granular material, the floor subgrade should be free of standing water, mud, and frozen soil. Before the placement of concrete, a vapor barrier may be placed on top of the granular material to provide additional moisture protection. Welded-wire mesh reinforcement should be placed in the upper half of the floor slab and attention should be given to the surface curing of the slab to minimize uneven drying of the slab and associated cracking and/or slab curling. The use of a blotter or cushion layer above the vapor retarder can also be considered for project specific reasons. Please refer to ACI 302.1R04 Guide for Concrete Floor and Slab Construction and ASTM E 1643 Standard Practice for Installation of Water Vapor Retarders Used in Contact with Earth or Granular Fill Under Concrete Slabs for additional guidance on this issue. We recommend that the floor slab be isolated from the foundation footings so differential settlement of the structure will not induce shear stresses on the floor slab. For maximum effectiveness, temperature and shrinkage reinforcements in slabs on ground should be positioned in the upper third of the slab thickness. The Wire Reinforcement Institute recommends the mesh reinforcement be placed 2 inches below the slab surface or upper one-third of slab thickness, whichever is closer to the surface. Adequate construction joints, contraction joints and isolation joints should also be provided in the slab to reduce the impacts of cracking and shrinkage. Please refer to ACI 302.1R04 Guide for Concrete Floor and Slab Construction for additional information regarding concrete slab joint design. If problems are encountered during the slab subgrade preparation, or if site conditions deviate from those encountered during our subsurface exploration, ECS should be notified immediately. We recommend that the project geotechnical engineer or his representative should be on site to monitor subgrade preparation and observe that unsuitable soils have been satisfactorily removed and the subgrade soils are suitable to support the slab or if the organic/peat soil is left below within 10 feet of the building pad a structural floor slab should be considered. Underslab Sub-Drainage Design Based on the groundwater levels observed during the subsurface exploration, we do not anticipate a significant volume of water will persist at the slab subgrade elevation. It should be noted however that surface runoff and limited groundwater seepage may accumulate at the slab subgrade such as the perched water condition. As such, we recommend that positive drainage be implemented around the perimeter of the proposed structure to reduce the potential for water accumulation under the floor slab and foundation elements, which could potentially weaken the bearing soils. Exterior Pavement Design We recommend that the pavement subgrade be prepared in accordance with the Subgrade Preparation and Earthwork Operations section of this report. Once the subgrade has been properly prepared, we recommend the following minimum pavement sections for the proposed


development. The minimum pavement sections were developed based on assumed traffic loads and a CBR of 3 for the subgrade soils. Table 1: Pavement Section Recommendations

Pavement Material

Compacted Material Thicknesses (Inches)

Flexible Pavement (Standard)

Flexible Pavement

(Heavy Duty)

Rigid Pavement (Standard)

Rigid Pavement (Heavy Duty)

Portland Cement Concrete

-- -- 5 6

Bituminous Surface Course 1½ 1½ -- --

Bituminous Base Course

2 3 -- --

Crushed Granular Subbase 8* 12* 6* 6*

Total Pavement Section Thickness

11½ 16½ 11 12

*If the organic/peat or deep fill soils are not removed, we recommend an additional 6 inches of aggregate subbase along with 2 layers of triaxial geogrid at the bottom of the aggregate material and 1 after the first lift to increase subgrade support and help to extend the serviceable life of the pavements. All pavement materials and construction should be in accordance with the Guidelines for AASHTO Pavement Design and IDOT Standards for Road and Bridge Construction. The pavement sections specified in the table above are general pavement recommendations based on the anticipated usage at the project site and were not developed based on specific traffic patterns/loading and resiliency factors, as those parameters were not provided by the design team. We recommend the project team provide ECS with design traffic loads so that we can verify the recommendations detailed herein are appropriate for the anticipated traffic loads. The table above provides “Standard” and “Heavy Duty” flexible and rigid pavement recommendations. The light-duty pavement section assumes that typical traffic loading will be limited to standard automobiles and does not account for more heavily loaded vehicles (i.e., multiple axle trucks) and should be used for parking lanes. The “Heavy-Duty” pavement section is recommended for pavements to be subjected with frequent traffic such as drive lanes, delivery areas, loading dock aprons and entrance/exit drive areas. It should also be noted that the pavement sections specified in the table above were developed for the anticipated in-service traffic conditions only and do not provide an allowance for construction traffic conditions or traffic conditions in excess of typical residential/collector street traffic. Therefore, if pavements will be constructed early during site development to accommodate construction traffic, consideration should be given to the construction of designated haul roads, where thickened pavement sections can be provided to accommodate the construction traffic, as well as the future in-service traffic. ECS can provide additional design assistance with pavement sections for haul roads upon request. If the organic/peat soils are allowed to remain below the pavement, shortened service lif and increase maintenance costs should be anticipated.


We recommend the crushed granular base course should be compacted to at least 95 percent of the maximum dry density obtained in accordance with ASTM D1557, Modified Proctor Method. During asphalt pavement construction, the wearing and leveling course should be compacted to a minimum of 93 percent of the theoretical density value. Prior to placing the granular material, the pavement subgrade soil should be properly compacted, observed to be stable during a final proofroll and free of standing water, mud, and frozen soil. Adequate construction joints, contraction joints and isolation joints should be provided in the areas of rigid pavement to reduce the impacts of cracking and shrinkage. Please refer to ACI 330R-92 Guide for Design of Concrete Parking Lots. The Guide recommends an appropriate spacing strategy for the anticipated loads and pavement thickness. It has been our experience that joint spacing closer to the minimum values results in a pavement with less cracking and better long term performance. The pavements should be designed and constructed with adequate surface and subsurface drainage. Where standing water develops, either on the pavement surface or within the base course layer, softening of the subgrade and other problems related to the premature deterioration of the pavement can be expected. Furthermore, good drainage should minimize the possibility of the subgrade materials beneath the pavement becoming saturated over a long period of time. Infiltration and subterranean water are the two sources of water that should be considered in the pavement design for the project. Infiltration is surface water that enters the pavement through the joints, pores, cracks in the pavement and through shoulders and adjacent areas pavements as a result of precipitation. Subterranean water is a source of water from a high water table on the site. The long term groundwater level on the site is estimated to be located at a depth of approximately 7 to 8 feet below existing site grades. Therefore, infiltration is the most important source of water to be considered for this project. Large, front loading trash dumpsters frequently impose concentrated front-wheel loads on pavements during loading. This type of loading typically results in rutting of the pavement and ultimately pavement failures. Therefore, we recommend that the pavement in trash pickup areas consist of the heavy duty rigid pavement section in Table 1. It should be noted that the pavement should be comprised of air-entrained Portland cement concrete with a minimum compressive strength of 4,000 psi and a minimum flexural strength of 650 psi. Adequate construction joints, contraction joints and isolation joints should be provided in the areas of rigid pavement to reduce the impacts of cracking and shrinkage. Please refer to ACI 330R-92 Guide for Design of Concrete Parking Lots. The Guide recommends an appropriate spacing strategy for the anticipated loads and pavement thickness. It has been our experience that joint spacing closer to the minimum values results in a pavement with less cracking and better long term performance. Pavement Maintenance

Regular maintenance and occasional repairs should be implemented to keep pavements in a serviceable condition. In addition, to help minimize water infiltration to the pavement section and within the base course layer resulting in softening of the subgrade and deterioration of the pavement, we recommend the timely sealing of joints and cracks using elastomeric caulk in existing pavement. We recommend exterior pavements should be reviewed for distress/cracks twice a year, once in the spring and once in the fall. In areas where deep deposits of


undocumented and variable fill soils are considered to be left in place, the Owner should anticipate increased in long term pavement maintenance due to compression of deep fill/organic peat over time. Sound maintenance programs should help maintain and enhance the performance of pavements and attain the design service life. A preventative maintenance program should be implemented early in the pavement life to be effective. The “standard in the industry” supported by research indicates that preventative maintenance should begin within 2 to 5 years of the placement of pavement. Failure to perform preventative maintenance will reduce the service life of the pavement and increase the costs for both corrective maintenance and full pavement rehabilitation.


PROJECT CONSTRUCTION RECOMMENDATIONS

General Construction Considerations We recommend that the subgrade preparation, installation of the foundations, and construction of slabs-on-grade and pavement be monitored by an ECS geotechnical engineer or his representative. Methods of verification and identification such as proofrolling, hand auger probes with in-situ DCP testing will be necessary to further evaluate the subgrade soils and identify unsuitable soils. The contractor should be prepared to over-excavate slab-on-grade and pavement subgrades at isolated locations (as necessary). We recommend that excavations of new foundations be monitored on a full-time basis by an ECS geotechnical engineer or his representative to verify that the soil bearing pressure and the subgrade materials will be suitable for the proposed structure and are consistent with the boring log information obtained during this geotechnical exploration. We would be pleased to provide these services. It is critical that the existing structures be properly demolished and backfilled prior to construction of the new project structure to limit the potential for future settlement of the proposed structure. Improper demolition and backfilling could lead to foundation and floor slab/pavement distress caused by unacceptable total and differential settlements. It has been our experience that many demolition contractors place the debris in excavations from the structure and cap with soil. These types of activities will not provide a suitable subgrade for foundations, slabs or pavements. ECS recommends that the demolition and backfilling operations at the project site be observed by an ECS field representative to confirm and document that work is performed in general accordance with the recommendations detailed herein and the backfill materials used are approved materials and adequately placed and compacted. We recommend additional test pit exploration program be performed prior to final design, mass grading activities and/or prior to bidding to better delineate the limits of the variable fill soils within the limits of the proposed building and positively identified and probe the locations of the former house and UST to evaluate the existence and limits of buried remnants of old structures, debris and unsuitable/deleterious soils/materials, if any. Consideration can be given to performing the test pit exploration program concurrently during the demolition phase of the project. If no test pit exploration program is performed prior to mass grading activities and/or prior to bidding, we recommend test pits be performed during construction to identify buried unsuitable existing fill soils at the site and the contractor should be prepared to remove and replace buried unsuitable existing fill soils without delay, especially in the southern portion of the proposed building footprint. All unsuitable materials and environmentally impacted soils (if any) should be removed and legally disposed off site and replaced with environmentally clean, inorganic fill and free of debris or harmful matter. Unsuitable materials and environmentally impacted soils removed from the project site should be disposed of in accordance with all applicable federal, state, and local regulations. The contractor should avoid stockpiling excavated materials immediately adjacent to the excavation walls. We recommend that stockpile materials be kept back from the excavation a minimum distance equal to the excavation depth to avoid surcharging the excavation walls. If


this is impractical due to space constraints, the excavation walls should be retained with bracing designed for the anticipated surcharge loading. Excavations should comply with the requirements of OSHA 29CFR, Part 1926, Subpart P, "Excavations" and its appendices, as well as other applicable codes. This document states that the contractor is solely responsible for the design and construction of stable, temporary excavations. The excavations should not only be in accordance with current OSHA excavation and trench safety standards but also with applicable local, state, and federal regulations. The contractor should shore, slope or bench the excavation sides when appropriate. Site safety is the sole responsibility of the contractor, who shall also be responsible for the means, methods and sequencing of construction operations. Current EPA and State law requires an asbestos survey prior to demolition or renovation activities. In the event regulated asbestos materials are confirmed to be present, any regulated asbestos materials that would be disturbed must removed prior to such disturbance by a licensed asbestos removal firm. All asbestos containing materials should be removed and disposed in accordance with Federal, State and Local regulations.

Foundation Subgrades If the existing undocumented fill below the slab is not completely to be removed and replaced, the shallow foundation excavations will still have to extend completely through the existing fill to encounter competent natural Silty CLAY soils. The corresponding depths of foundation over-excavation may range to depths of about 5 to 6 feet below existing grades at boring locations B-2 and B-4, respectively and to depths of 8 to 15 feet below existing site grades at boring locations B-3 and B-1, respectively. As an alternative to complete removal and replacement where deep existing fill soils are encountered (i.e., at boring location B-4 and other areas that maybe revealed through test pit exploration program), ground improvement consisting of aggregate piers discussed in Option 2 can be considered. Again, we recommend additional test pit exploration program be performed to better delineate the lateral and vertical limits of the variable fill soils that needs to be removed and replaced or remediated within the limits of the proposed building. During project construction, we recommend that visual soil classification by an ECS representative supplemented with hand auger probes and/or DCP testing be performed to a depth below the foundation subgrade equivalent to ½ the footing width (i.e., ½ B), or a minimum of 5 feet below each isolated column footing and continuous footings. Visual soil classification supplemented with hand auger probes and/or DCP testing should be performed at each column footing and at approximately 20-foot intervals along continuous footings to verify the suitability of the soils to support the recommended maximum net allowable bearing pressure. Construction Dewatering Based on the groundwater conditions encountered at the project site, we do not anticipate that significant dewatering efforts will be required during construction of shallow foundations, slab-on-grade and at grade parking lot/pavement and provided excavations will not extend to a


depth of 8 feet or greater below existing site grades at some locations. Groundwater can be encountered during removal and replacement of unsuitable fill soils which may to extend below 15 feet in some foundation areas. It should also be noted that perched water and/or surface runoff may introduce water into the project site. The general contractor should be prepared to remove any accumulated water prior to the placement of fill and concrete. If excavations will extend to 8 feet or greater, the contractor should be prepared to dewater. We anticipate that the removal of any accumulated water can be achieved utilizing drainage trenches and a sump and pump system. Exposure to the environment may weaken the soils at the footing bearing level if the foundation excavations remain open for too long a period. Therefore, foundation concrete should be placed the same day that excavations are dug. If the bearing soils are softened by surface water intrusion or exposure, the softened soils must be removed from the foundation excavation bottom immediately prior to placement of concrete.

Closing This report has been prepared to aid in the evaluation of this property and to assist the architect and/or engineer in the design of this project. The scope is limited to the specific project and locations described herein and our description of the project represents our understanding of the significant aspects relative to soil and foundation characteristics. In the event that any change in the nature or location of the proposed construction outlined in this report are planned, we should be informed so that the changes can be reviewed and the conclusions of this report modified or approved in writing by the geotechnical engineer. It is recommended that all construction operations dealing with earthwork and foundations be reviewed by an experienced geotechnical engineer to provide information on which to base a decision as to whether the design requirements are fulfilled in the actual construction. If you wish, we would welcome the opportunity to provide field construction services for you during construction. The analysis and recommendations submitted in this report are based upon the data obtained from the soil borings and tests performed at the locations as indicated on the Boring Location Plan and other information referenced in this report. This report does not reflect variations, which may occur between the borings. In the performance of the subsurface exploration, specific information is obtained at specific locations at specific times. However, it is a well known fact that variations in soil conditions exist on most sites between boring locations and also such situations as groundwater levels vary from time to time. The nature and extent of variations may not become evident until the course of construction. If variations then appear evident, after performing on-site observations during the construction period and noting characteristics and variations, a reevaluation of the recommendations for this report will be necessary. In addition to geotechnical engineering services, ECS Midwest, LLC has the in-house capability to perform multiple additional services as this project moves forward. These services include the following:

• Environmental Consulting;

• Geophysical Testing (ReMi and PHSA)

• Project Drawing and Specification Review; and,


• Construction Material Testing / Special Inspections We would be pleased to provide these services for you. If you have questions with regard to this information or need further assistance during the design and construction of the project please feel free to contact us.

APPENDIX

General Location Plan Boring Location Plan Boring Logs

Unified Soil Classification System Reference Notes For Boring Logs

Figure 1

GENERAL LOCATION PLAN USGS Topographic Map

ECS Project No. 16:10248 Proposed Hanover Park

Community Bank 6800 Barrington Road Hanover Park, Illinois

Approximate Project Site Location

0

5

10

15

20

25

30

805

800

795

790

785

780

S-1

S-2

S-3

S-4

S-5

S-6

SS

SS

SS

SS

SS

SS

18

18

18

18

18

18

16

14

16

18

18

18

Topsoil Depth [10"]

(CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Contains Slight Asphalt, Dark Brownand Black, Moist, Stiff to Very Stiff

(PT) ORGANIC PEAT, Black, Wet, Very Soft

(OL/OH) ORGANIC SOIL, Greenish Gray, Wet,Soft

(CL/ML) SILTY CLAY, Trace Sand,TraceGravel, Gray, Moist, Stiff

END OF BORING @ 20'

222

245

223

123

WOH

1

346

4 14.6

1.25

9

22.3

2.25

5 24.92.0

5 166.2

1

43.8

0.5

10 21.0

1.25

CLIENT

Grund & Reisterer Architects

JOB #

10248

BORING #

B-1

SHEET

PROJECT NAME

Hanover Park Community Bank

ARCHITECT-ENGINEER

SITE LOCATION

6800 Barrington Rd, Hanover Park, IllinoisNORTHING EASTING STATION

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN-SITU THE TRANSITION MAY BE GRADUAL.

WL WS WD BORING STARTED 08/27/14

WL(BCR) WL(ACR) BORING COMPLETED 08/27/14 CAVE IN DEPTH

WL RIG CME-45 FOREMAN Steve Euker DRILLING METHOD CFA

DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION

DESCRIPTION OF MATERIAL

WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS

BOTTOM OF CASING LOSS OF CIRCULATION

CALIBRATED PENETROMETER TONS/FT2

PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %

ROCK QUALITY DESIGNATION & RECOVERY

RQD% REC.%

STANDARD PENETRATIONBLOWS/FT808

1 OF 1

0

5

10

15

20

25

30

805

800

795

790

785

780

S-1

S-2

S-3

S-4

S-5

S-6

SS

SS

SS

SS

SS

SS

18

18

18

18

18

18

18

18

18

18

18

18

Bituminous Pavement Depth [8"], Gravel Depth[13"]

(CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Brown and Greenish Gray, Moist, VeryStiff(CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Contains Slight Topsoil, Black, Moist,Very Stiff(CL/ML) SILTY CLAY, Trace Sand,TraceGravel, Brown to Gray at 12 Feet, Moist, Stiff toVery Stiff

END OF BORING @ 20'

1332

453

222

347

346

579

5 19.73.5

819.5 2.75

4 20.71.75

11 20.03.25

10

16.9

1.75

16 19.5

3.0

CLIENT


JOB #

10248

BORING #

B-2

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION






DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%

STANDARD PENETRATIONBLOWS/FT807½

1 OF 1

0

5

10

15

20

25

30

805

800

795

790

785

780

S-1

S-2

S-3

S-4

S-5

S-6

SS

SS

SS

SS

SS

SS

18

18

18

18

18

18

14

16

18

18

18

18

Bituminous Pavement Depth [3"], Gravel Depth[12"](CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Brown and Dark Brown, Moist, Very Stiff

(CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Contains Slight Topsoil, Black, Moist,Medium Stiff

(CL/ML) SILTY CLAY, Trace Sand,TraceGravel, Brown to Gray at 12 Feet, Moist, Stiff toVery Stiff

END OF BORING @ 20'

345

333

222

223

234

357

9 19.03.25

6

22.3

2.25

4 35.10.75

5 21.01.25

7 20.1

1.75

12

18.2 2.5

CLIENT


JOB #

10248

BORING #

B-3

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION



WL 8 WS WD BORING STARTED 08/27/14

WL(BCR) WL(ACR) 2½ BORING COMPLETED 08/27/14 CAVE IN DEPTH


DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

0

5

10

15

20

25

30

805

800

795

790

785

780

S-1

S-2

S-3

S-4

S-5

S-6

SS

SS

SS

SS

SS

SS

18

18

18

18

18

18

14

16

18

18

18

18

Bituminous Pavement Depth [4"], Gravel Depth[8"](CL/ML FILL) SILTY CLAY, Dark Brown andBlack, Moist, Very Stiff

(CL/ML FILL) SILTY CLAY, Contains SlightAsphalt, Black, Moist, Very Stiff

(CL/ML) SILTY CLAY, Trace Sand,TraceGravel, Brown to Gray, Moist, Very Stiff to Hard

END OF BORING @ 20'

233

234

123

467

358

346

6 18.83.5

734.02.5

5 21.73.0

13 16.84.5+

13 17.3

3.75

10 22.8

2.75

CLIENT


JOB #

10248

BORING #

B-4

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION



WL 18 WS WD BORING STARTED 08/27/14

WL(BCR) WL(ACR) 17½ BORING COMPLETED 08/27/14 CAVE IN DEPTH


DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%

STANDARD PENETRATIONBLOWS/FT807½

1 OF 1

0

5

10

15

20

25

30

805

800

795

790

785

780

S-1

S-2

S-3

SS

SS

SS

18

18

18

14

16

18

Bituminous Pavement Depth [5"], Gravel Depth[11"]

(CL/ML FILL) SILTY CLAY, Trace Sand,TraceGravel, Contains Slight Asphalt, Dark Brownand Black, Moist, Hard

(CL/ML) SILTY CLAY, Trace Sand,TraceGravel, Yellowish Brown, Moist, Stiff,Petrochemical Odor

END OF BORING @ 7½'

345

344

345

9 21.84.25

830.61.75

926.8

1.0

CLIENT


JOB #

10248

BORING #

B-5

SHEET

PROJECT NAME


ARCHITECT-ENGINEER

SITE LOCATION






DE

PT

H (

FT

)

SA

MP

LE

NO

.

SA

MP

LE

TY

PE

SA

MP

LE

DIS

T.

(IN

)

RE

CO

VE

RY

(IN

)

SURFACE ELEVATION


WA

TE

R L

EV

ELS

ELE

VA

TIO

N (

FT

)

BLO

WS

/6"

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS



PLASTICLIMIT %

WATERCONTENT %

LIQUIDLIMIT %


RQD% REC.%


1 OF 1

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D 2487)

Major Divisions Group

Symbols Typical Names Laboratory Classification Criteria

GW

Well-graded gravels, gravel-sand mixtures, little or no fines

Cu = D60/D10 greater than 4 Cc = (D30)2/(D10xD60) between 1 and 3

Cle

an g

rave

ls

(Litt

le o

r no

fines

)

GP

Poorly graded gravels, gravel-sand mixtures, little or no fines

Not meeting all gradation requirements for GW

d

GMa

u

Silty gravels, gravel-sand mixtures

Atterberg limits below “A” line or P.I. less than 4

Gra

vels

(M

ore

than

hal

f of c

oars

e fra

ctio

n is

la

rger

than

No.

4 s

ieve

siz

e)

Gra

vels

with

fine

s (A

ppre

ciab

le a

mou

nt o

f fin

es)

GC

Clayey gravels, gravel-sand-clay mixtures

Atterberg limits below “A” line or P.I. less than 7

Above “A” line with P.I. between 4 and 7 are borderline cases requiring use of dual symbols

SW

Well-graded sands, gravelly sands, little or no fines

Cu = D60/D10 greater than 6 Cc = (D30)2/(D10xD60) between 1 and 3

Cle

an s

ands

(L

ittle

or n

o fin

es)

SP

Poorly graded sands, gravelly sands, little or no fines

Not meeting all gradation requirements for SW

d

SMa

u

Silty sands, sand-silt mixtures

Atterberg limits above “A” line or P.I. less than 4

Coa

rse-

grai

ned

soils

(M

ore

than

hal

f of m

ater

ial i

s la

rger

than

No.

200

Sie

ve s

ize)

San

ds

(Mor

e th

an h

alf o

f coa

rse

fract

ion

is

smal

ler t

han

No.

4 s

ieve

siz

e)

San

ds w

ith fi

nes

(App

reci

able

am

ount

of

fines

)

SC

Clayey sands, sand-clay mixtures D

eter

min

e pe

rcen

tage

s of

san

d an

d gr

avel

from

gra

in-s

ize

curv

e.

Dep

endi

ng o

n pe

rcen

tage

of f

ines

(fra

ctio

n sm

alle

r tha

n N

o. 2

00 s

ieve

siz

e), c

oars

e-gr

aine

d so

ils

are

clas

sifie

d as

follo

ws:

Le

ss th

an 5

per

cent

GW

, GP

, SW

, SP

M

ore

than

12

perc

ent

G

M, G

C, S

M, S

C

5 to

12

perc

ent

Bor

derli

ne c

ases

requ

iring

dua

l sym

bols

b

Atterberg limits above “A” line with P.I. greater than 7

Limits plotting in CL-ML zone with P.I. between 4 and 7 are borderline cases requiring use of dual symbols

ML

Inorganic silts and very fine sands, rock flour, silty or clayey fine sands, or clayey silts with slight plasticity

CL

Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays

S

ilts

and

clay

s (L

iqui

d lim

it le

ss th

an 5

0)

OL Organic silts and organic silty clays of low plasticity

MH

Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts

CH

Inorganic clays of high plasticity, fat clays

S

ilts

and

clay

s (L

iqui

d lim

it gr

eate

r tha

n 50

)

OH

Organic clays of medium to high plasticity, organic silts

Fine

-gra

ined

soi

ls

(Mor

e th

an h

alf m

ater

ial i

s sm

alle

r tha

n N

o. 2

00 S

ieve

)

H

ighl

y O

rgan

ic

soils

Pt

Peat and other highly organic soils

Plasticity Chart

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70 80 90 100

Liquid Limit

Plas

ticity

Inde

x

"A" line

CH

MH and OH

CL

ML and OLCL-ML

a Division of GM and SM groups into subdivisions of d and u are for roads and airfields only. Subdivision is based on Atterberg limits; suffix d used when L.L. is 28 or less and the P.I. is 6 or less; the suffix u used when L.L. is greater than 28. b Borderline classifications, used for soils possessing characteristics of two groups, are designated by combinations of group symbols. For example: GW-GC,well-graded gravel-sand mixture with clay binder. (From Table 2.16 - Winterkorn and Fang, 1975)

REFERENCE NOTES FOR BORING LOGS

Reference Notes for Boring Logs_2010-10-29.doc © 2010 ECS Corporate Services, LLC. All Rights Reserved

COHESIVE SILTS & CLAYS UNCONFINED COMP. STRENGTH, QP

2 (TSF) SPT3 (BPF)

CONSISTENCY (COHESIVE ONLY)

<0.25 <2 Very Soft 0.25 - 0.49 3 - 4 Soft 0.50 - 0.99 5 - 8 Medium Stiff 1.00 - 1.99 9 - 15 Stiff 2.00 - 3.99 16 - 30 Very Stiff 4.00 - 8.00 31 - 50 Hard

>8.00 >50 Very Hard

GRAVELS, SANDS & NON-COHESIVE SILTS SPT3 (BPF) DENSITY

<4 Very Loose 5 - 10 Loose

11 - 30 Medium Dense 31 - 50 Dense 51 - 99 Very Dense >100 Partially Weathered Rock

to Intact Rock

RELATIVE PROPORTIONS

Trace <5% Little 5% - <15% With 15% - <30%

Adjective 30% - <50% (ex: “Silty”)

1The water levels are those levels actually measured in the borehole at the times indicated by the symbol. The measurements are relatively reliable when augering, without adding fluids, in granular soils. In clay and cohesive silts, the determination of water levels may require several days for the water level to stabilize. In such cases, additional methods of measurement are generally taken. 2Typically estimated via pocket penetrometer or Torvane shear test and expressed in tons per square foot (tsf). 3Standard Penetration Test (SPT) refers to the number of hammer blows (blow count) of a 140 lb. hammer falling 30 inches on a 2-inch OD split-spoon sampler required to drive the sampler 12 inches (ASTM D 1586). “N-value” is another term for “blow count” and is expressed in blows per foot (bpf).

WATER LEVELS1

WL Water Level (WS)(WD) (WS) While Sampling (WD) While Drilling

BCR Before Casing Removal ACR After Casing Removal WL Water Level as stated DCI Dry Cave-In WCI Wet Cave-In

DRILLING SAMPLING SYMBOLS & ABBREVIATIONS SS Split Spoon Sampler PM Pressuremeter Test ST Shelby Tube Sampler RD Rock Bit Drilling WS Wash Sample RC Rock Core, NX, BX, AX BS Bulk Sample of Cuttings REC Rock Sample Recovery % PA Power Auger (no sample) RQD Rock Quality Designation

%HSA Hollow Stem Auger

PARTICLE SIZE IDENTIFICATION DESIGNATION PARTICLE SIZES Boulders 12-inches (300-mm) or larger Cobbles 3-inches to 12- inches (75-mm to 300-mm) Gravel: Coarse ¾-inch to 3-inches (19-mm to 75-mm) Fine 4.75-mm to 19-mm (No. 4 sieve to ¾-inch) Sand: Coarse 2.00-mm to 4.75-mm (No. 10 to No. 4 sieve) Medium 0.425-mm to 2.00-mm (No. 40 to No. 10 sieve) Fine 0.074-mm to 0.425-mm (No. 200 to No. 40 sieve) Silt & Clay (“Fines”) <0.074-mm (smaller than a No. 200 sieve)

MATERIALS

ASPHALT

CONCRETE

SUBBASE STONE / GRAVEL

TOPSOIL

FILL Man-placed or disturbed soils

GW WELL-GRADED GRAVEL

gravel-sand mixtures, little or no fines

GP POORLY-GRADED GRAVEL

gravel-sand mixtures, little or no fines

GM SILTY GRAVEL

gravel-sand-silt mixtures

GC CLAYEY GRAVEL

gravel-sand-clay mixtures

SW WELL-GRADED SAND

gravelly sand, little or no fines

SP POORLY-GRADED SAND

gravelly sand, little or no fines

SM SILTY SAND

sand-silt mixtures

SC CLAYEY SAND

sand-clay mixtures

ML SILT

non-plastic to medium plasticity

MH ELASTIC SILT

high plasticity

CL LEAN CLAY

low to medium plasticity

CH FAT CLAY

high plasticity

OL ORGANIC SILT or CLAY

non-plastic to low plasticity

OH ORGANIC SILT or CLAY

high plasticity

PT PEAT

highly organic soils

WEATHERED ROCK

IGNEOUS ROCK

METAMORPHIC ROCK

SEDIMENTARY ROCK

10248 hanover park community bank geotechnical...

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