geotechnical engineering services report...1. classification (astm d 2487 / 2488) 2. moisture...

GEOTECHNICAL ENGINEERING SERVICES REPORT

For the proposed

PUBLIC TRAINING FACILITY 4111 VINTAGE BOULEVARD

DENTON, TEXAS

Prepared for

Mr. Herman Lawson City of Denton – Facilities Management

869 S Woodrow Lane Denton, Texas 76205

Prepared by

Professional Service Industries, Inc. 310 Regal Row, Suite 500

Dallas, Texas 75247 Telephone (214) 330-9211

PSI Project No. 03421219

September 2, 2016

TABLE OF CONTENTS

Page No.

1.0 PROJECT INFORMATION ............................................................................... 1

1.1 Project Authorization ............................................................................................ 1 1.2 Project Description ............................................................................................... 1 1.3 Purpose and Scope of Services ........................................................................... 1

2.0 SITE AND SUBSURFACE CONDITIONS ........................................................ 3

2.1 Site Location and Description ............................................................................... 3 2.2 Field Exploration .................................................................................................. 3 2.3 Laboratory Testing ............................................................................................... 4 2.4 Site Geology ......................................................................................................... 4 2.5 Subsurface Conditions ......................................................................................... 4 2.6 Groundwater Information...................................................................................... 5

3.0 EVALUATION AND RECOMMENDATIONS ................................................... 6

3.1 Soil Shrink-Swell Potential ................................................................................... 6 3.2 Geotechnical Discussion ...................................................................................... 6 3.3 Site Preparation and Fill Materials ....................................................................... 7 3.4 Straight Shaft Drilled Pier Recommendations ...................................................... 8 3.5 Drilled and Underreamed Piers Foundation Recommendations. ....................... 11 3.6 Shallow Foundations Recommendations ........................................................... 12 3.7 Floor Slab Recommendations ............................................................................ 13 3.8 Seismic Design .................................................................................................. 15

4.0 PAVEMENT RECOMMENDATIONS ............................................................. 16

4.1 Subgrade Soil Preparation ................................................................................. 16 4.2 Pavement Section .............................................................................................. 16

5.0 CONSTRUCTION CONSIDERATIONS.......................................................... 18

5.1 Secondary Design Considerations ..................................................................... 18 5.2 Construction Materials Testing ........................................................................... 19 5.3 Moisture Sensitive Soils/Weather Related Concerns ......................................... 19 5.4 Drainage and Groundwater Concerns................................................................ 19 5.5 Excavations ........................................................................................................ 19

6.0 REPORT LIMITATIONS ................................................................................. 21

APPENDIX A

Site Vicinity Map Aerial Plan with Boring Location Boring Location Plan Boring Logs Key to Terms and Symbols Used on Logs

APPENDIX B PSI Project No. 0342-85019 PSI Project No. 0342-85019 Addendum I

DENTON PUBLIC TRAINING FACILITY PSI REPORT NO. 03421219 4111 VINTAGE BOULEVARD, DENTON, TEXAS SEPTEMBER 2, 2016

PROFESSIONAL SERVICE INDUSTRIES, INC. PAGE 1 OF 21

1.0 PROJECT INFORMATION 1.1 Project Authorization Professional Service Industries, Inc. (PSI) has completed the geotechnical exploration for the proposed Public Training Facility to be located at the northeast corner of 4111 Vintage Boulevard in Denton, Texas. This geotechnical engineering study was authorized by Mr. Herman with The City of Denton on July 18, 2016 by signing the Proposal Acceptance. The scope of the study was performed in general accordance with PSI Proposal No. 184505-R dated July 18, 2016. 1.2 Project Description Project information was provided to PSI by Mr. Brett Atchison with PGAL. The information provided included the project site plan, location, and brief description of the project. Based on the information provided, the proposed development consists of:

A burn tower; Flash chamber; Outdoor classroom; Propane tank area; Future Roof Building; and Parking and drive areas

Based on the planned improvements, this proposal is based on the assumed structural loading as follows:

Column Load: 360 kips or less Wall Load: Less than 3 kips per linear foot Floor Slab: Less than 150 psf

PSI previously performed a geotechnical exploration for the proposed development and provided recommendations in PSI report No. 0342-85019, dated April 11, 2008 and PSI report No. 0342-85019 Addendum I dated June 24, 2008. It is understood that the project was put on hold since then. Based on Google Earth information, the site is covered with grass and scattered trees. It is anticipated that boring locations are accessible to the truck mounted drill rig. The report is based on the assumption that finished grades within the building area will be within 4 feet of the existing grades. The geotechnical recommendations presented in this report are based on the available project information, site location, laboratory testing, and the subsurface materials described in this report. If any of the noted information is incorrect, please inform PSI in writing so that we may amend the recommendations presented in this report if appropriate and if desired by the client. PSI will not be responsible for the implementation of its recommendations when it is not notified of changes in the project. 1.3 Purpose and Scope of Services The purpose of this study was to explore the subsurface conditions at the site and to provide geotechnical evaluation and recommendations for the proposed construction. The scope of work for this project included drilling five borings extending to a depth of approximately 25 and 60 feet below the existing grade. The scope also included performing laboratory testing and preparing



this geotechnical report containing geotechnical recommendations as well as a review of previous reports and incorporating the previous analysis into the current study. This report briefly outlines the testing procedures, presents available project information, describes the site and subsurface conditions, and presents recommendations regarding the following:

Site preparation recommendations;

Estimated potential soil movements associated with moisture induced volume changes;

Foundation types, depths, allowable bearing capacities, and an estimate of potential movement;

General pavement section design criteria and pavement subgrade preparation;

Definition of the seismic site class using the International Building Code (IBC) 2012 edition; and

Comments regarding factors that may impact construction and performance of the proposed construction.

The scope of services did not include an environmental assessment for determining the presence or absence of wetlands, or hazardous or toxic materials in the soil, bedrock, surface water, groundwater, or air on or below, or around this site. Any statements in this report or on the boring logs regarding odors, colors, and unusual or suspicious items or conditions are strictly for informational purposes. A geologic fault study to evaluate the possibility of surface faulting at this site was beyond the scope of this investigation. Should you desire a detailed fault study, please contact us.



2.0 SITE AND SUBSURFACE CONDITIONS 2.1 Site Location and Description The project site is located at 4111 Vintage Boulevard in Denton, Texas. Based on the available aerial photos and the provided survey, the project site is generally flat and the ground cover is grass with scattered trees. Based on the site layout, it appears that within the plan area of the proposed development anticipated cuts and fills will be less than 4 feet to achieve the finished grade. The truck mounted drill rig experienced no difficulties in moving around the site during the field exploration. 2.2 Field Exploration Subsurface conditions at the site were explored by drilling ten borings at the approximate locations shown on the Aerial Plan with Boring Locations included in the Appendix A. The borings were located using available landmarks and hand-held GPS and were drilled to the depths given in Table 2.1 below.

TABLE 2.1: BORING LOCATIONS AND DEPTHS

Boring Number Boring Location Depth Drilled

B-101 Administration Building

Area* 25 feet

B-102 Residential Burn Building

Area* 25 feet

B-103 Burn Tower Area 25 feet

B-201 Burn Tower Area 55 feet

B-202 Outdoor Classroom Area 55 feet

Note: * denotes a building referenced that has since been removed from the scope of the project. The boring location plan also shows the locations of borings B-01 through B-11 performed in 2008 during the previous study. Elevations of the ground surface at the boring locations were not provided to PSI and should be determined by others prior to construction. Therefore, the references to depth of the various materials encountered are from the existing grade at the time of drilling (August, 2016). The borings were drilled and sampled in general accordance with ASTM standards. Drilling equipment utilized for this project included truck-mounted rotary drilling equipment with appropriate support vehicles. Field activities were accomplished in accordance with PSI’s safety manual. The borings were drilled using continuous flight auger drilling techniques. The borings were sampled continuously to a depth of ten-feet and at five-foot intervals thereafter. Soil formations were sampled using a three-inch O.D. seamless steel tube sampler (ASTM D 1587) and a two-inch O.D. split barrel sampler (ASTM D 1586). A hand penetrometer was used as an aid in evaluating the relative shear strength of the soils encountered during drilling. The hand penetrometer readings are shown on the boring logs at the corresponding sample depths. In addition, rock formations were tested at five-foot intervals using Texas Cone Penetrometer in general accordance with TEX-132 E.



Groundwater level measurements were recorded at boring locations during the field operations and were noted on the boring logs. The borings were backfilled with soil cuttings after the drilling operations were completed. The subsurface conditions during drilling were monitored, logged and visually classified in the field by a geotechnical technician. Field notes were maintained for soil types and description, water levels, changes in subsurface conditions, and drilling conditions. After completion of field activities, the samples were transported to the laboratory in general accordance with ASTM D 4220. The soil samples were sealed in plastic bags and placed in secured containers prior to being transported to the geotechnical laboratory. Boring logs, which include soil descriptions, water level information, laboratory test data, stratifications, classifications based on the ASTM D 2487 and D2488, and sample types and depths are included in the Appendix. A key to descriptive terms and symbols used on the boring logs is also presented in the Appendix. 2.3 Laboratory Testing Laboratory testing of soils was performed in general accordance with applicable ASTM procedures. The laboratory testing program was established so that the engineering design parameters produced from the tests are appropriate for use in the engineering analyses and in support of the conclusions and recommendations. The geotechnical laboratory testing included the following tests:

1. Classification (ASTM D 2487 / 2488) 2. Moisture Content (ASTM D 2216) 3. Atterberg Limits (ASTM D 4318) 4. Percent Soil Particles Finer than No. 200 Sieve (ASTM D1140) 5. Unconfined Compression Test (ASTM D 2166)

The samples not tested in the laboratory will be stored for a period of 60 days subsequent to submittal of this report and will be discarded after this period, unless other arrangements are made prior to the disposal period. 2.4 Site Geology As shown on the Sherman Sheet of the Geologic Atlas of Texas published by the Bureau of Economic Geology of the University of Texas at Austin, the site is located in an area where Quaternary Age terraced alluvial deposits are located at the surface. The terraced alluvial deposits generally consist of clays, silts, sands, and gravels deposited within the floodplain of the river areas and their tributaries 2.5 Subsurface Conditions The subsurface conditions identified at the boring locations are shown on the boring logs included in the Appendix section of this report. A key to terms and symbols used on the logs is also included in the Appendix. Based on the subsurface conditions identified by the exploratory borings, generalized subsurface profiles at this site is shown in Table 2.2.



TABLE 2.2 GENERALIZED SUBSURFACE PROFILE

Stratum Depth Range

(feet) Description

I 0 to 4.5 Fat Clay (CH), stiff to hard, dark brown

II 2 to 33 Lean Clay (CL), very stiff to hard, brown and light brown, with calcareous deposits

III 30 to 50 Shale, soft to hard, gray

IV 50 to 55 Limestone, hard to very hard, gray

2.6 Groundwater Information The initial water levels were measured in the open boreholes during drilling and attempts were made to measure final water levels. At boring location B-103, groundwater was encountered during drilling at a depth of 22 feet and at the completion of drilling activities at a depth of 22 feet. At boring location B-202 groundwater was encountered during drilling at a depth of 30.5 feet and at the completion of drilling activities at a depth of 29.5 feet. The remaining borings appeared dry at completion. Groundwater levels fluctuate seasonally as a function of rainfall, proximity to creeks, rivers and lakes, the infiltration rate of the soil, seasonal and climatic variations and land usage. Water seepage will largely depend on the permeability of the soils. If more detailed water level information is required, observation wells or piezometers could be installed at the site, and water levels could be monitored. The groundwater levels presented in this report are the levels that were measured at the time of our field activities. It is recommended that the contractor determine the actual groundwater levels at the site at the time of the construction activities to determine the impact, if any, on the construction procedures.



3.0 EVALUATION AND RECOMMENDATIONS 3.1 Soil Shrink-Swell Potential The resu lts of laboratory plasticity tests indicate that moderate to high plasticity clay soils are present at this site. The soils have a tendency to swell when soil moisture increases and shrink when the soil moisture decreases. The amount of potential soil movement due to shrinking and swelling with soil moisture variations is represented or indicated by Potential Vertical Rise (PVR). In designing the soil-supported structures, the structural/civil engineer should take movements associated with shrinking-swelling soils into account. PVR estimates are based on an assumed depth known as “Active Depth” to which the soil moisture variations could occur due to seasonal variations. It is noted that the active depth assumed herein may not represent the moisture variations that can occur at greater depths due to the presence of large tree root systems that could desiccate the soils, the presence of other heating units, or soil wetting due to pipe leaks, poor drainage, etc. It is very difficult to predict the moisture variations under the structure during its service life. The PVR estimates provided herein should be considered approximate probable estimates based on industry standard practice and experience, and the movements predicted herein should not be construed as absolute values that could occur in the field. Using the Texas Department of Transportation (TXDOT) TEX-124-E method, the estimated PVR value is on the order of 1 to 2½ inches. Poor drainage and water infiltration into the foundation soils can be detrimental to the ground supported structures. Excessive wetting of soil (due to accumulation of water), or, excessive drying (due to the presence large trees, etc) could possibly result in greater PVR values than those estimated herein. It is recommended that the moisture-related problems be corrected immediately. It is important to help reduce the possibility of moisture changes by following the precautions shown below: 1. Direct surface runoff away from structures by sloping the subgrade away from the slabs. 2. Extend paving or other impervious coverings, such as sidewalks, to the slab edge. 3. Extend roof drain downspouts so that the discharge is at least 5 feet from the slab. 4. Avoid placing trees or shrubs adjacent to slab. 5. Avoid excessive drying of soil around the slab. 3.2 Geotechnical Discussion Based on the project information as well as field and laboratory results, the proposed developments will be supported by straight shaft pier foundation system. Both grade supported and structurally suspended floor slab systems can be considered for the building. For any ground supported structures, it will be necessary to perform modifications to the subgrade in order to reduce the movement associated with shrinking and swelling soils. Detailed geotechnical recommendations are presented below.



3.3 Site Preparation and Fill Materials The following site preparations apply to the proposed building areas. It is recommended that existing vegetation be removed from the proposed construction area. The removal depth of organics could be 6 inches. A PSI representative should witness the earthwork activities. After stripping of deleterious materials and excavating to the desired grade, the exposed soil should be proof-rolled to locate any soft or loose areas. Proof-rolling shall be performed in accordance with Item 216 of Texas Department of Transportation (TxDOT), Standard specification for construction of highways, streets and bridges (TxDOT Spec) or equivalent procedure. Soils that are observed to rut or deflect excessively under the moving load should be undercut and replaced with properly compacted fill materials. A PSI representative should witness the proof-rolling and undercutting activities. It is advisable to perform the earth-work activities during a period of dry weather. The proof rolled subgrade shall be scarified to a depth of 6-inches and compacted as shown in Table 3.1. After the completion of proof-rolling and undercutting activities, necessary fill placement may commence. Fill materials should be free of organics, miscellaneous debris and of particles greater than 3 inches. If water must be added, it should be uniformly applied and thoroughly mixed into the soil by disking or scarifying. Care should be taken to apply compaction throughout the fill areas. The moisture content and degree of compaction of the fill should be maintained until the construction of structures. Each lift of fill should be tested by a representative of the geotechnical engineer prior to placement of subsequent lifts. Lift thicknesses and compaction requirements are shown in Table 3.1 Compaction Specifications. Common Fill: Common fill should be cohesive soils with a plasticity index of less than 30. Common fill may consist of on-site/imported materials and may be used in structural and non-structural areas of the site. The first layer of common fill material should be placed in a relatively uniform horizontal lift and be adequately keyed into the prepared subgrade soils. Common fill should be placed and compacted to the specifications as shown in Table 3.1. Select Fill: Select fill materials shall be sandy lean clay or lean clay (CL) soils that have a liquid limit not greater than 35 and a plasticity index between 8 and 18. Select fill should be placed and compacted to the specifications as mentioned in Table 3.1. Moisture Conditioned Clay Fill: Moisture conditioned fill is on-site or imported cohesive soil that is pre-swelled by mechanically mixing water during the compaction process which is also referred as Moisture Treated Subgrade (MTS). The first layer of moisture conditioned fill should be placed in a relatively uniform horizontal lift and be adequately keyed into the prepared subgrade soils. Moisture Conditioned Fill shall have a clay lump size of less than 2-inches. Moisture Conditioned Fill should be placed and compacted to the specifications as shown in as shown in Table 3.1. Lime Treated Soils: The lime treated soils are soils that are treated with 6 to 8% of lime expressed as percent of the dry weight of the soil to be treated. In order to determine the percentage of lime addition, lime series testing should be performed in accordance with ASTM D6276 or TxDOT test method TEX-112-E (pH-Series). In addition, the soils should be checked for sulfates (TEX-145-E) prior to the use of lime. Lime treatment should be performed in accordance with the applicable provisions of Item 260 of the TxDOT Specification. Lime Treated



soils can be used as Select Fill materials. Lime treated soil should be placed and compacted to the specifications as shown in Table 3.1.

TABLE 3.1: COMPACTION SPECIFICATIONS

FILL TYPE LOOSE LIFT THICKNESS

MINIMUM PERCENT OF MAXIMUM DRY DENSITY (MDD)

RANGE OF COMPACTION

MOISTURE FROM OPTIMUM MOISTURE

CONTENT (OMC)

PROCTOR TEST

METHOD

Common Fill or Moisture Treated

Soils 8 inches 95 or greater +2% or greater ASTM D 698

Select Fill 8 inches 95 or greater 0% to +4% ASTM D 698

Lime Treated Soils 8 inches 95 or greater 0% to +4% ASTM D 698

3.4 Straight Shaft Drilled Pier Recommendations The column and wall loads for the proposed structure may be supported on drilled straight shafts. The axial load carrying capacity of a drilled shaft can be computed using the static method of analysis. According to this method, axial capacity, Q, at a given penetration is taken as the sum of the skin friction on the side of the shaft, Qs, and the end or point bearing at the shaft tip, Qp, so that:

Q = Qs + Qp = fAs + qAp where As and Ap represent, respectively, the embedded surface area and the end area of the shaft; f and q represent, respectively, the unit skin friction and the unit end or point bearing. The total allowable axial capacity in compression will be the summation of the allowable frictional capacity and the allowable end bearing capacity. The total allowable axial capacity in tension will be the allowable frictional capacity alone neglecting end bearing component. 3.4.1 Axial Capacity: For this site, based on the evaluation of the subsurface conditions, field and laboratory test results, it is recommended that straight drilled shafts bear in the shale or limestone. The drilled shafts should extend at least 3 feet or 2-diameters into shale/rock. Allowable unit skin friction and allowable end bearing values are shown in Table 3.2. Skin friction in the overburden soils should be neglected. A factor of safety of at least 2.0 is included for both the unit skin friction and end bearing to arrive at the allowable values. Based on the final grade at the foundation locations, the length of the shaft and the penetration into the bearing stratum should be determined using the recommended allowable side friction and end bearing values. After the design is finalized, PSI should be given the opportunity to check the final length, embedment depth and bearing elevation.

Table 3.2. Recommended Allowable Unit Skin Friction and End Bearing Values

STRATUM TOP OF ROCK DEPTH (FEET) SKIN FRICTION (TSF) END BEARING (TSF)

Gray Shale Encountered between 30 and

35 feet 1.25 12



3.4.2 Expansive Soil Considerations: Drilled shafts extending through potentially expansive soils are subjected to vertical uplift loads should the soils become moist or wet and swell against the shaft. For this reason, each drilled shaft should be designed with sufficient steel reinforcement to resist the tensile stresses caused by the expansive soil uplift. Drilled shafts placed within swelling soils and should be checked for an expansive soil uplift load of 38d kips; where d is the diameter of the shaft in feet. The reinforcement in the shaft should be checked for this uplift load alone neglecting any dead loads on the shaft. The uplift load is calculated based on 1,000 pounds per square foot of uplift friction due to swelling soils along the shaft surface area to a depth of 12 feet. The drilled shaft should be extended to a minimum of 3 feet into the gray limestone layer to provide resistance to the swelling uplift load alone. This penetration is calculated using a factor of safety of 1.3 for friction resistance in the limestone. Wall loads and Grade Beams: Wall loads should be transmitted to the drilled shafts by grade beams and the grade beam should be structurally connected to the shafts. Void boxes can be provided under the grade beams to avoid movements associated with shrinking and swelling soils. A minimum of 6-inch void space is recommended beneath the grade beams. These voids can be produced using compressible cardboard carton forms manufactured specifically for this purpose. Care should be exercised so that the forms are not crushed, damaged or allowed to become saturated prior to placement of the concrete. In addition, barriers that will not rapidly decay should be placed or constructed along the sides of the cardboard carton forms to prevent soil intrusion into the void after the carton forms decay. Galvanized steel or aluminum sheet metals are two examples of materials that can be used for this purpose. 3.4.3 Settlement: An isolated drilled shaft having a diameter of less than 60 inches designed as discussed, the foundation settlement should be about ½ inch. A detailed group settlement analysis was not performed, as the actual group configurations are unknown at this time. However, for a shaft group bearing in limestone, large settlements are not anticipated. If a group settlement analysis is desired, PSI should be contacted to perform such a settlement analysis. 3.4.4 Lateral Capacity: For drilled shafts, the soils as well as the rigidity of the shaft will resists the lateral loads applied to the shaft. After the location, loads, and other pertinent information are provided, PSI can assist in performing lateral load analyses based on methods ranging from chart solutions to the ‘p-y’ approach utilizing computer programs such as LPILE or COM 624. The lateral loads on the shaft can also be designed based on the criteria provided in the FHWA-Drilled Shaft Manual. The lateral design information regarding the ‘p-y’ data is provided in Table 3.3. This relationship between the soil resistance (p) and pile deflection (y) is commonly referred to as ‘p-y’. Along the depth of the shaft, soil resistance (p) is expressed as a non-linear function of lateral shaft deflection (y). Various researchers developed ‘p-y’ criteria for different types of soils. The ‘p-y’ curves can be automatically generated using the computer program LPILE. The program LPILE was developed by Lymon Reese and Shin-Tower Wang, Ensoft, Inc.



TABLE 3.3: SOIL PARAMETERS TO BE USED IN THE LATERAL LOAD ANALYSES

SOIL TYPE ‘P-Y’ CRITERIA

EFFECTIVE UNIT WEIGHT,

(PCF)

SU OR QU KS (PCI) OR KC(PCI) OR

E (PSI) 50 OR KRM RQD

In-Situ Clays

Stiff Clay w/o Free Water

Criteria 125 Su: 1,250 psf

Ks = 500 Kc = 200

50 = 0.007 --

Moisture Conditioned

Clays Soft Clay 125 Su: 750 psf -- 50 = 0.010 --

Gray Shale Weak Rock

Criteria 75 Qu = 150 psi Er = 30,000 krm = 0.0005 70

Note: Su-Undrained Shear Strength (psf); Qu-Unconfined Compressive Strength (psi); Er- Initial Modulus (psi); 50 – strain corresponding to one-half the principle stress; krm – a constant for overall stiffness. RQD- Rock Quality Designation.

3.4.5 Group Action: A group of drilled shafts subjected to vertical or lateral loads may not necessarily have the same capacity as the sum of the capacities of the individual shafts. For axially or laterally loaded drilled shafts, published results indicate that the ratio of capacity per shaft in a group to that of a single isolated shaft typically ranges from 0.5 to 1.0. For axially loaded shafts, this efficiency factor depends on the spacing or distance between each shaft. In planning groups of drilled shafts embedded in rock, a minimum center-to-center spacing of 2D (where D is the diameter or the width) is recommended to avoid the reduction in capacity. For laterally loaded shafts, the efficiency factor depends on the shaft spacing (distance between each shaft) and on the direction of loading with respect to the orientation of the shaft group. Research indicates a minimum spacing of 3 diameters to 6 diameters is required depending on the direction of loading with respect to the orientation of the shafts in a group. Group action should be checked after the actual shaft spacing is determined. Further, if the shaft spacing is designed to be closer, construction sequence and other installation issues must be addressed. PSI should be contacted, after the shaft group orientation, spacing and loading direction is determined. 3.4.6 Groundwater and Construction: Groundwater was encountered during drilling operations at B-103 at a depth of 22 feet and at B-202 at a depth of 29.5 feet. Therefore, drilled shaft excavations are likely to experience groundwater infiltration. Temporary casing may be used where necessary to stabilize pier holes and to reduce water inflow. If more than 4 inches of water collects in the shaft excavation in less than one-half hour a temporary casing is recommended. The successful completion of drilled pier excavations will depend, to a large extent, on the suitability of the drilling equipment together with the skill of the operator. The sequence of operations should be scheduled so that each pier can be drilled, reinforcing steel placed, and the concrete poured in a continuous, rapid, and orderly manner to reduce the time that the excavation is open. Shafts should be clean and be free of all loose materials prior to placement of concrete. The drilled shafts should be installed in accordance with Item 416 of TxDOT specifications, ACI 336.1 specifications, or FHWA-NHI-10-016 guidelines. We recommend a PSI representative be present



to verify the bearing stratum, bearing depth, bearing soil condition, bearing area and that the pier installation procedures meet the specifications. 3.5 Drilled and Underreamed Piers Foundation Recommendations. It is recommended that the development foundations be supported on drilled and underreamed piers. The piers should be placed at a depth of about 12 feet below the existing ground surface bearing on stiff clay soils. Individual piers bearing in the clays can be designed for a maximum allowable net bearing pressure of 6,000 psf for dead plus live loads and 4,000 psf for dead plus sustained live loads, whichever results in the larger underream. Piers extending through expansive soils are potentially subjected to vertical uplift loads should the soils become moist and swell. For this reason, each pier should be designed with sufficient steel reinforcement to resist the tensile stresses. Piers placed within natural swelling soils at this site should be checked for reinforcement with a tension loads of 38d kips; where d is the diameter of the piers in feet. The reinforcement of the pier should be checked for this tension load alone neglecting any dead loads on the pier. A single isolated pier with a bell diameter of about 8 feet or less and designed as discussed should experience a settlement on the order of one-half inch or less. However, if a cluster of closely spaced piers is planned, PSI should be contacted to calculate the estimated amount of settlement. After the foundation sizes and configuration are finalized, PSI should be contacted in estimating the amount of settlement. Wall loads should be transmitted to the drilled piers by grade beams and the grade beam should be structurally connected to the piers. Void boxes should be provided under the grade beams to avoid movements associated with shrinking and swelling soils. A minimum 4-inch void space is recommended beneath the grade beams and pier caps. These voids can be produced using compressible cardboard carton forms manufactured specifically for this purpose. Care should be exercised that that the forms are not crushed, damaged, or allowed to become saturated prior to placement of the concrete. In addition, barriers that will not rapidly decay should be placed or constructed along the sides of the cardboard carton forms to prevent soil intrusion into the void after the carton forms decay. Galvanized steel or aluminum sheet metals are two examples of materials that can be used for this purpose. For the construction of the underream or bell, a bell diameter to pier diameter ratio of 2 to 1 is recommended. We believe that a bell to pier diameter ratio of up to 3 to 1 can be achieved at this site, if the bell angle to the horizontal is 60˚. The uplift capacity of drilled and underreamed piers can be determined from the following semi-empirical relationship:

Qu = Nu *Su **(D2 – d2)/4

Where: Qu = ultimate uplift capacity, tons

Nu = 3.5*(H/D) 9 Su = Undrained Shear Strength, tons per square feet D = diameter of underream or bell, feet d = diameter of shaft, feet



H = depth to base of bell below ground surface, feet For bells excavated within the natural clay, the value of Undrained Shear Strength, “Su” in the above equation can be taken as 0.75 tons per square foot. The ultimate value should be reduced by a factor of safety of 2.0 for transient and wind loads and 3.0 for sustained loads. The lateral loads on shallow drilled and underreamed piers can be resisted by passive resistance of the soil. The allowable passive resistance of soil may be taken as 1,000 psf. The value includes a factor of safety of 2.0. Determination of the lateral load carrying capacity using the passive earth pressure does not predict the lateral pier-head load versus pier-head deflection behavior of the drilled pier. It is recommended that the passive resistance from the upper two feet of soil be neglected and the passive resistance from any uncompacted fill material be neglected. The successful completion of drilled and underreamed excavations will depend, to a large extent, on the suitability of the drilling and underreaming equipment together with the skill of the operator. The sequence of operations should be scheduled so that each underream can be completed, reinforcing steel placed and the concrete poured in a continuous, rapid and orderly manner to reduce the time that the excavation is open. Groundwater was not encountered during drilling operations. Therefore, drilled pier excavations are not likely to experience groundwater infiltration. Due to the fluctuations of the groundwater table with the season and amount of precipitation, the possibility of encountering groundwater during field operations cannot be dismissed. Temporary casing may be used where necessary to stabilize pier holes and to reduce water inflow. If more than 4 inches of water collects in the pier excavation in less than one-half hour a temporary casing is recommended. Underream excavations and the bearing area should be clear and free of loose materials prior to placement of concrete. Placement of concrete in the excavations should commence immediately after the underream excavation is complete. A PSI representative should verify that the underream installation procedures meet specifications. Installation of the piers can be carried out in accordance with ACI 336.1, Item 416 of TxDOT specifications, or the guidelines provided in the Drilled Shaft Manual, Publication No. FHWA-IS-99-025. 3.6 Shallow Foundations Recommendations The proposed building may be supported on shallow spread footings/grade beams or monolithic, steel reinforced stiffened slab-on-grade foundation system (i.e., a waffle type grade beam configuration), provided that some differential movement can be tolerated and provided the recommended subgrade preparation activities are performed.

For the support of isolated columns using conventional spread footings or continuous footings or grade beams, structural fill option (Option 1) is recommended; and, moisture conditioning (Option 2) should not be performed. The subgrade should be prepared as mentioned in Section 3.7.2, Option 1: Select Fill.

For monolithic, steel reinforced stiffened slab-on-grade foundation system (i.e., a waffle type grade beam configuration), structural fill option or moisture conditioning should be performed and the subgrade should be prepared as mentioned in Section 3.7.2.



Shallow foundations could be placed at least two feet below the finished grade on properly compacted structural fill soils and can be designed for a net allowable bearing pressure of 2,400 psf for dead load plus live loads, and 1,600 psf for dead plus sustained live loads, whichever results in a larger bearing area. The grade beams should have a minimum width of 10 inches even if the actual bearing pressure

is less than the design value. The perimeter grade beams should bear at least 24 inches below adjacent surface grades (i.e. bottoms of beams and pads should bear at least 24 inches below the adjacent ground surface). If soft or loose soils are encountered at the design bearing level, they should be undercut to stiff or dense soils and the excavation back-filled with concrete. Single isolated footing, with width no larger than eight feet, designed as discussed above, should experience a settlement of less than one inch. If a cluster of closely spaced footings (i.e., if the center to center spacing of the footings is less than two times the width of the footing) are planned, PSI should be contacted to calculate the amount of settlement. The base adhesion/frictional resistance and the passive soil resistance will resist the horizontal loads on shallow foundations. For a footing cast against natural clay soil or compacted soil, the adhesion/frictional resistance and the passive soil resistance values for both transient and sustained loading conditions are given herein. For transient loading conditions, an ultimate base adhesion resistance of 440 psf and an ultimate passive resistance of 1,600 psf can be used. For sustained loading conditions, a frictional co-efficient of 0.36 and an ultimate passive resistance of 240 psf per foot depth is recommended. A factor of safety of 2.0 is recommended to arrive at the allowable values. Passive resistance from the upper two feet of soil should be neglected. Also, the passive resistance of any un-compacted fill material should be neglected. The uplift resistance of a shallow foundation formed in an open excavation will be limited to the weight of the foundation concrete and the soil above it. For design purposes, the ultimate uplift resistance should be based on effective unit weights of 120 and 150 pcf for soil and concrete, respectively. This value should then be reduced by an appropriate factor of safety to arrive at the allowable uplift load. If there is a chance of submergence, the buoyant unit weights should be used. The foundation excavations should be observed by a representative of PSI prior to steel or concrete placement to assess that the foundation materials are capable of supporting the design loads and are consistent with the materials discussed in this report. Soft or loose soil zones encountered at the bottom of the footing or grade beam excavations should be removed and replaced with properly compacted fill as directed by the geotechnical engineer. After opening, footing or grade beam excavations should be observed and concrete placed as quickly as possible to avoid exposure of the footing or grade beam bottoms to wetting and drying. Surface run-off water should be drained away from the excavations and not be allowed to pond. If possible, the foundation concrete should be placed during the same day the excavation is made. If it is required that footing or grade beam excavations be left open for more than one day, they should be protected to reduce evaporation or entry of moisture. 3.7 Floor Slab Recommendations Based on the subsurface conditions at this site, the soil movements associated with shrink-swell potential will govern the design of the floor slab. The use of a structurally suspended floor slab



system is one appropriate means to isolate the proposed building structure from the underlying subgrade. If a grade supported floor slab system is desired, remedial earthwork measures should be performed as described in this section. Detailed geotechnical recommendations are present below. 3.7.1 Structurally Supported Floor Slab Systems In order to mitigate the movements associated with soil shrink-swell, it is recommended that the slab system be structurally suspended above grade on appropriate deep foundation system with a minimum of 6-inch of void space between the structures (grade beams, pier caps and floor slab system) and the soil. For structurally suspended slab system, no significant site preparation is anticipated other than general site grading. These voids can be produced using compressible cardboard carton forms manufactured specifically for this purpose. Care should be exercised so that the forms are not crushed, damaged or allowed to become saturated prior to placement of the concrete. In addition, barriers that will not rapidly decay should be placed or constructed along the sides of the cardboard carton forms to prevent soil intrusion into the void after the carton forms decay. Galvanized steel or aluminum sheet metals are two examples of materials that can be used for this purpose. 3.7.2 Grade Supported Floor Slab Systems A slab-on-grade floor slab can be constructed provided the site is prepared in accordance with the recommendations mentioned herein. Based on the subsurface conditions at this project site, the estimated PVR is on the order of 1 to 2½ inches. Typically, it is the industry practice to consider 1-inch soil movement as the tolerable level for structures of this type. In order to reduce the soil movements, the following options for subgrade preparation should be followed: Option 1: Select Fill

In order to reduce the PVR to about one inch and provide uniform support to the floor slab system, it is recommended that at least 5 feet of low-expansive select fill should be placed below the floor-slab. The select fill should be placed within the plan area of the structure and to a distance of at least 5 feet beyond the perimeter of the structure including areas sensitive to movement such as building entrances and flatwork. Plasticity and compaction requirements for the select fill are provided in Section 3.3 Site Preparation and Fill Materials of this report.

Option 2: Select Fill and Moisture Conditioned Clay For this option, in order to reduce the PVR to about one inch and provide uniform support to the floor slab system, the engineered soil layers are given in Table 3.5.

TABLE 3.5: MOISTURE CONDITION CLAY RECOMMENDATIONS

PVR MATERIAL TYPE LAYER THICKNESS,

FEET ELEVATION RANGE BELOW

FINISHED GRADE, FEET

1 inch

Select Fill or Flexible Base or Lime Treated Clay Cap

1 +0 to -1

Moisture Conditioned Clay 6 -1 to -7

Note: Finished Grade Elevation is assumed to be +0 feet.



The moisture conditioned soil should be placed within the plan area of the structure and to a distance of at least five feet beyond the perimeter of the structure and include building entrances and flatwork sensitive to movements. Placement and compaction requirements are provided in the Section 3.3 Site Preparation and Fill Materials of this report.

For this option, moisture levels must be maintained throughout the life of the project. It is noted that if the moisture conditioned clay dries there is possibility for shrinking movements to occur. Keeping the soils moist can be accomplished by the addition of landscape irrigation and construction of impermeable surfaces such as the floor and site paving to limit moisture loss. Larger vegetation should be placed at least the mature height of the vegetation away from the structure to limit the impact of the root system on the soils supporting the floor slab.

An allowable net bearing pressure of 600 psf can be used for slab-on-grade provided the subgrade is prepared as recommended above. For the recommended subgrade preparation below floor slab, a total estimated settlement of less than one inch should be expected under the floor slab. A vapor retarder such as polyethylene sheeting should be provided directly beneath the ground supported slab. Adequate construction joints and reinforcement should be provided to reduce the potential for cracking of the floor slab due to differential movement. 3.8 Seismic Design

The International Building Code (IBC) 2012 edition was used in this report. As part of this code, the design of structures must consider dynamic forces resulting from seismic events. These forces are dependent upon the magnitude of the earthquake event, as well as, the properties of the soils that underlie the site. Part of the IBC code procedure to evaluate seismic forces requires the evaluation of the Seismic Site Class, which categorizes the site based upon the characteristics of the subsurface profile within the upper 100 feet of the ground surface. To define the Seismic Site Class for this project, we have interpreted the results of our test borings drilled within the project site and estimated appropriate soil properties below the base of the borings, as permitted by the code. The estimated soil properties were based upon data available in published geologic reports as well as our experience with subsurface conditions in the general site area. Based upon the evaluation, the subsurface conditions within the site are consistent with the characteristics of the Specific Site Class C as defined in the building code.



4.0 PAVEMENT RECOMMENDATIONS 4.1 Subgrade Soil Preparation Based on subsurface soil information, PSI recommends that at least the top 8 inches of the surficial soils be lime stabilized. It is important to note that increasing the depth of lime treatment to 12 inches below the surface will cause significant improvements in the pavement life. Lime treatment should extend at least one foot outside the perimeter of the pavement. Lime treatment of subgrade soils is described in Section 3.3 Site Preparation and Fill Materials. If lime stabilization is not desired, 12 inches of select fill can be provided below the pavement materials. 4.2 Pavement Section AASHTO design methodology can be used to design the pavements. According to AASHTO design methodology, the pavement design thickness primarily depends on strength of the subgrade soils and type of traffic. Traffic includes several types of vehicles with various magnitudes of axle loads that may be subjected to the pavement during its service life. The design involves a traffic analysis that converts various types of vehicles with various magnitudes axle loads to a number of 18-kip equivalent single axle load (ESAL) repetitions. The design engineer should perform the traffic analyses to compute the number of ESALs repetitions that would be subjected to the pavement during its service life or design life. Based on the computed ESALs, an economical and appropriate pavement can be designed accordingly. AASHTO low volume design methodology can also be used to design pavements. The low volume design methodology depends on typical subgrade conditions for 6 different U.S climatic zones and provides minimum thickness for 3 different levels of traffic. Based on AASHTO low volume design and our previous experience, we have provided pavement thickness for both flexible pavement and rigid pavement systems in tables 4.1 and 4.2 below. The tables include thickness design corresponding to 3 levels of traffic (low, medium and high). It is recommended that the pavement design thicknesses correspond to following:

Low traffic condition: Parking areas expected to receive only car traffic.

Medium traffic condition: Secondary drive areas and/or parking areas expected to receive delivery vans, light trucks, and busses.

High traffic condition: Parking and drive areas with heavy or frequent traffic, fire lanes, trash pickup areas, main access drive ways, and 18-wheeler loading/unloading.

TABLE 4.1: MINIMUM RIGID PAVEMENT SECTION

PAVEMENT MATERIAL(S) DESIGN THICKNESS

LOW MEDIUM HIGH

Portland Cement Concrete 5.0 inches 6.0 inches 7.0 inches

Pavement Subgrade As Discussed in Section 4.1



TABLE 4.2: MINIMUM FLEXIBLE PAVEMENT SECTION

PAVEMENT MATERIAL(S) DESIGN THICKNESS

LOW MEDIUM HIGH

Hot Mix Asphalt Concrete

Item 340 TXDOT-Type D 2.0 inches 2.0 inches 3.0 inches

Granular Base Material

Item 247. TXDOT-Type A or D, Grade 1 or 2 6.0 inches 8.0 inches 8.0 inches

Pavement Subgrade As Discussed in Section 4.1

Large front-loading garbage trucks 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, it is recommended that the pavement in trash pickup areas consist of a minimum 7-inch thick, reinforced concrete slab. During the construction phase of this project, site grading should be kept in such a way that the water drains freely off the construction areas. Proper finishing of concrete pavements requires the use of sawed and sealed joints. Construction joints should be designed in accordance with current Portland Cement Association guidelines. Joints should be sealed to reduce the potential for water infiltration into pavement joints and subsequent infiltration into the supporting soils. Joint spacing is recommended at 15-foot intervals for plain concrete. Dowel bars should be used to transfer loads at the transverse joints. Normal periodic maintenance will be required. The design of steel reinforcement should be in accordance with accepted codes. The concrete should have a minimum compressive strength of 3,500 psi at 28 days. The concrete should also

be designed with 5 1 percent entrained air to improve workability and durability. Pavement materials and construction procedures should conform to TXDOT or appropriate city and county requirements. Surface water infiltration to the pavement subgrade layers may soften the subgrade soils. Considering several factors in the pavement design can reduce surface infiltration. The following are some of the factors that need to be emphasized in order to maintain proper drainage.

1) Appropriate slopes should be provided to drain the water freely away from the pavement surface.

2) Joints should be properly sealed and maintained.

3) Side drains or sub drains along a pavement section may be provided.

4) Proper pavement maintenance programs such as sealing surface cracks, and immediate repair of distressed pavement areas should be adopted.

5) If a curb and gutter system is used, the curb should extend through the base and at least 3 inches into the subgrade. This will help reduce migration of subsurface water into the pavement base course from adjacent areas.



5.0 CONSTRUCTION CONSIDERATIONS 5.1 Secondary Design Considerations The following information has been developed after review of numerous problems concerning foundations throughout the area. It is presented here for your convenience. If these features are incorporated in the overall design and specifications for the project, performance of the project will be improved.

1. Prior to construction, the area to be covered by building should be prepared so that water will not pond beneath or around the building after periods of rainfall. In addition, water should not be allowed to pond on or around pavements.

2. Roof drainage should be collected and transmitted by pipe to a storm drainage system or to an area where the water can drain away from buildings and pavements without entering the soils supporting buildings and pavements.

3. Sidewalks should not be structurally connected to buildings. They should be sloped away from buildings so that water will be drained away from structures.

4. Paved areas and the general ground surface should be sloped away from buildings on all sides so that water will always drain away from the structures. Water should not be allowed to pond near buildings after the floor slabs and foundations have been constructed.

5. Backfill for utility lines that are located in pavement, sidewalk and building areas should consist of on-site fill. The backfill should be compacted as described in the Site Preparation and Fill Materials section of this report. Lesser lift thicknesses may be required to obtain adequate compaction.

6. Care should be exercised to make sure that ditches for utility lines do not serve as conduits that transmit water beneath structures or pavements. The top of the ditch should be sealed to inhibit the inflow of surface water during periods of rainfall.

7. Flower beds and planting areas should not be constructed along building perimeters. Constructing sidewalks or pavements adjacent to buildings would be preferable. If required, flower beds and planting areas could be constructed beyond the sidewalks away from the buildings. If it is desired to have flower beds and planting areas adjacent to a building, the use of above grade concrete box planters, or other methods that reduce the likelihood of large changes in moisture content of soils adjacent to or below structures should be considered.

8. Water sprinkling systems should not be located where water will be sprayed onto building walls and subsequently drain downward and flow into the soils beneath foundations.

9. Trees in general should not be planted closer to a structure than the mature height of the tree. A tree planted closer to a structure than the recommended distance may extend its roots beneath the structure, allowing removal of subgrade moisture and/or causing structural distress.

10. Utilities that project through slab-on-grade floors should be designed with some degree of flexibility and/or with a sleeve to reduce the potential for damage to the utilities should movement occur.



11. Soil supported floor slabs are subject to vertical movements. This often causes distress to interior wall partitions supported on soil supported floor slabs. This should be considered in the design of soil supported floor slabs.

5.2 Construction Materials Testing It is recommended that PSI be retained to provide observation and testing of construction activities involved in the foundations, earthwork, and related activities of this project. PSI cannot accept any responsibility for any conditions that deviates from those described in this report, nor for the performance of the foundations if not engaged to also provide construction observation and testing for this project. Observation of all foundation bearing materials, peir construction activities, structural steel and subgrade treatment operations should be performed by a representative of PSI. Density testing should be performed at a rate of one per 2,500 square feet per 8-inch lift in building areas, one test per 10,000-square feet per 8-inch lift in paved areas and 1 per 100 linear feet per 8-inch lift in utility trench backfill. A moisture-density relationship (Proctor), Atterberg’s limit and minus 200 sieve test should be performed for each material encountered at finished subgrade elevation. 5.3 Moisture Sensitive Soils/Weather Related Concerns The upper fine-grained soils discovered at this site could be sensitive to disturbances caused by construction traffic and changes in moisture content. During wet weather periods, increases in the moisture content of the soil can cause significant reduction in the soil strength and support capabilities. In addition, soils that become wet may be slow to dry and thus significantly retard the progress of grading and compaction activities. Construction schedules should account for these conditions during wetter times of the year. 5.4 Drainage and Groundwater Concerns Water should not be allowed to collect in the foundation excavation, on floor slab areas, or on prepared subgrades of the construction area either during or after construction. Undercut or excavated areas should be sloped toward one corner to facilitate removal of any collected rainwater, ground water, or surface runoff. Positive site surface drainage should be provided to reduce infiltration of surface water around the perimeter of the building and beneath the floor slabs. The grades should be sloped away from the building and surface drainage should be collected and discharged such that water is not permitted to infiltrate the backfill and floor slab areas of the building. PSI recommends that the contractor determine the actual ground water levels at the site at the time of the construction activities. It may be expedient to drill auger holes or excavate test pits adjacent to the building area immediately prior to construction to determine the prevailing water level elevation. Any water accumulation should be removed from excavations by pumping. Should excessive and uncontrolled amounts of seepage occur, the geotechnical engineer should be consulted. 5.5 Excavations In Federal Register, Volume 54, No. 209 (October 1989), the United States Department of Labor, Occupational Safety and Health Administration (OSHA) amended its "Construction Standards for



Excavations, 29 CFR, part 1926, Subpart P". This document was issued to better insure the safety of workmen entering trenches or excavations. It is mandated by this federal regulation that excavations, whether they be utility trenches, basement excavation or footing excavations, be constructed in accordance with the new OSHA guidelines. It is our understanding that these regulations are being strictly enforced and if they are not closely followed the owner and the contractor could be liable for substantial penalties. The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations as required to maintain stability of both the excavation sides and bottom. The contractor's "responsible person", as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations. We are providing this information solely as a service to our client. PSI does not assume responsibility for construction site safety or the contractor's or other party’s compliance with local, state, and federal safety or other regulations.



6.0 REPORT LIMITATIONS The recommendations submitted in this report are based on the available subsurface information obtained by PSI and design details furnished by the client for the proposed developments at Denton Public Training Facility in Denton, Texas. If there are any revisions to the plans for this project, or if deviations from the subsurface conditions noted in this report are encountered during construction, PSI should be notified immediately to determine if changes in the foundation recommendations are required. If PSI is not notified of such changes, PSI will not be responsible for the impact of those changes on the project. The geotechnical engineer warrants that the findings, recommendations, specifications, or professional advice contained herein have been made in accordance with generally accepted professional geotechnical engineering practices in the local area. No other warranties are implied or expressed. This report may not be copied, except in the entirety, without expressed written permission from PSI. PSI is not responsible for any claims, damages, or liability associated with the interpretation or re-use of the subsurface data or engineering analysis or the conclusions or recommendations of others based on the findings and recommendations presented herein. After the plans and specifications are more complete, the geotechnical engineer should be retained and provided the opportunity to review the final design plans and specifications to check that our engineering recommendations have been properly incorporated into the design documents. At that time, it may be necessary to submit supplementary recommendations. If PSI is not retained to perform these functions, PSI will not be responsible for the impact of those conditions on the project. This geotechnical report has been prepared for the exclusive use of the City of Denton and their representatives for the specific application of the proposed Denton Public Training Facility in Denton, Texas.


PROFESSIONAL SERVICE INDUSTRIES, INC.

APPENDIX A

N

Site Vicinity Map

PSI Project No.: 03421219

Project Site

Denton Public Training Facility

4111 Vintage Boulevard

Denton, Texas310 Regal Row, Suite 500

Dallas, Texas 75247

PHONE: (214) 330-9211 – FAX: (214) 333-2853

310 Regal Row, Suite 500

Dallas, Texas 75247

PHONE: (214) 330-9211 – FAX: (214) 333-2853

Aerial Plan

with Boring Location

PSI Project No.: 03421219

N

2015 Aerial Photo

Denton Public Training Facility

4111 Vintage Boulevard

Denton, Texas

25

21

16

17

18

16

6

15

25

27

28

113

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GROUND WATER DURING DRILLING: Not EncounteredGROUND WATER AFTER DRILLING: DryDELAYED GROUND WATER: N/A

DATE DRILLED: 8/22/16DEPTH TO GROUND WATER

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LATITUDE:LONGITUDE:

APPROX. SURFACE ELEVATION:

TYPE OF BORING: SOLID FLIGHT AUGERLOCATION: See Boring Location Plan PSI Project No.: 03421219

Denton Public Training Facility4111 Vintage Boulevard, Denton, Texas

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0

5

10

15

20

25

30

35

40

45

50

LIMESTONE, very hard, gray

156.00T:100(0.50")

LL

UN

IT D

RY

WT

.(P

CF

)

CO

MP

RE

SS

IVE

ST

RE

NG

TH

(ts

f)

LOG OF BORING B-201



PLA

ST

ICIT

YIN

DE

X

PL PI

UUUCSO

IL T

YP

E

% P

AS

SIN

G#2

00 S

IEV

E

DESCRIPTION


PLA

ST

ICLI

MIT



LIQ

UID

LIM

IT


SP

T -

NT

CP

- T

(BLO

WS

/FT

.)

0 1 2 3 4 5

SA

MP

LES

NOTES:

HP

COMPRESSIVESTRENGTH

TONS/SQ.FT.

MO

IST

UR

EC

ON

TE

NT

(%

)

DE

PT

H,

FT

.

BL_

DA

LLA

S -

PS

IHO

US

TO

N.G

DT

- 9

/2/1

6 1

5:4

7 -

P:\0

342

DA

LLA

S G

EO

\201

6 G

EO

PR

OJE

CT

S\0

3421

219

DE

NT

ON

PU

BLI

C T

RA

ININ

G F

AC

ILIT

Y, D

EN

TO

N, T

X -

CIT

Y O

F D

EN

TO

N -

FA

CIL

ITIE

S M

AN

AG

EM

EN

T\A

PP

EN

DIX

\034

2121

9.G

PJ

50

55

60

65

70

75

80

85

90

95

100

24

21

24

13

14

14

10

11

11

17

21

127

FILL - FAT CLAY, very stiff, brown

LEAN CLAY (CL), hard, light brown and gray

-with calcareous deposits above 10 feet

-with sand below 20 feet

SHALE, soft to hard, gray

9.43

T:100(1.25")

T:100(5.5")

LL

UN

IT D

RY

WT

.(P

CF

)

CO

MP

RE

SS

IVE

ST

RE

NG

TH

(ts

f)

LOG OF BORING B-202

GROUND WATER DURING DRILLING: 30.5 FeetGROUND WATER AFTER DRILLING: 29.5 FeetDELAYED GROUND WATER: N/A


PLA

ST

ICIT

YIN

DE

X

PL PI

UUUCSO

IL T

YP

E

% P

AS

SIN

G#2

00 S

IEV

E

DESCRIPTION


PLA

ST

ICLI

MIT


LATITUDE:LONGITUDE:




LIQ

UID

LIM

IT


SP

T -

NT

CP

- T

(BLO

WS

/FT

.)

0 1 2 3 4 5

SA

MP

LES

NOTES:

HP

COMPRESSIVESTRENGTH

TONS/SQ.FT.

MO

IST

UR

EC

ON

TE

NT

(%

)

DE

PT

H,

FT

.

BL_

DA

LLA

S -

PS

IHO

US

TO

N.G

DT

- 9

/2/1

6 1

5:4

7 -

P:\0

342

DA

LLA

S G

EO

\201

6 G

EO

PR

OJE

CT

S\0

3421

219

DE

NT

ON

PU

BLI

C T

RA

ININ

G F

AC

ILIT

Y, D

EN

TO

N, T

X -

CIT

Y O

F D

EN

TO

N -

FA

CIL

ITIE

S M

AN

AG

EM

EN

T\A

PP

EN

DIX

\034

2121

9.G

PJ

0

5

10

15

20

25

30

35

40

45

50

CONSISTENCY N-VALUE

(Blows/Foot) SHEAR STRENGTH

(tsf) HAND PEN VALUE

(tsf)

Very Soft 0 TO 2 0 TO 0.125 0 TO 0.25

Soft 2 TO 4 0.125 TO 0.25 0.25 TO 0.5

Firm 4 TO 8 0.25 TO 0.5 0.5 TO 1.0

Stiff 8 TO 15 0.5 TO 1.0 1.0 TO 2.0

Very Stiff 15 TO 30 1.0 TO 2.0 2.0 TO 4.0

Hard >30 >2.0 OR 2.0+ >4.0 OR 4.0+

KEY TO TERMS AND SYMBOLS USED ON LOGS

CONSISTENCY OF COHESIVE SOILS

DESCRIPTION OF ROCK QUALITY

RQD

Very Poor (VPo) 0 TO 25

Poor (Po) 25 TO 50

Fair (F) 50 TO 75

Good (Gd) 75 TO 90

Excellent (ExInt) 90 TO 100

ROCK QUALITY DESIGNATION

(RQD)

DESCRIPTION OF RECOVERY

% CORE RECOVERY

Incompetent < 40

Competent 40 TO 70

Fairly Continuous 70 TO 90

Continuous 90 TO 100

RECOVERY

ROCK CLASSIFICATION

DENSITY (GRANULAR)

CONSISTENCY (COHESIVE)

THD (BLOWS/FT)

FIELD IDENTIFICATION

Very Loose (VLo) Very Soft (VSo) 0 TO 8 Core (height twice diameter) sags under own weight

Loose (Lo) Soft (So) 8 TO 20 Core can be pinched or imprinted easily with finger

Slightly Compact (SICmpt)

Stiff (St) 20 TO 40 Core can be imprinted with considerable pressure

Compact (Cmpt) Very Stiff (VSt) 40 TO 80 Core can only be imprinted slightly with fingers

Dense (De) Hard (H) 80 TO 5”/100 Core cannot be imprinted with fingers but can be penetrated with pencil

Very Dense (VDe) Very Hard (VH) 5”/100 to 0”/100

Core cannot be penetrated with pencil

SOIL DENSITY OR CONSISTENCY

DEGREE OF PLASTICITY

PLASTICITY INDEX (PI)

SWELL POTENTIAL

None or Slight 0 to 4 None

Low 4 to 20 Low

Medium 20 to 30 Medium

High 30 to 40 High

Very High >40 Very High

DEGREE OF PLASTICITY OF COHESIVE SOILS

MORHS’ SCALE

CHARACTERISTICS EXAMPLES APPROXIMATE THD

PEN TEST

5.5 to 10 Rock will scratch knife Sandstone, Chert, Schist, Granite, Gneiss, some Limestone

Very Hard (VH)

0” to 2”/100

3 to 5.5 Rock can be scratched with knife blade

Siltstone, Shale, Iron Deposits, most Limestone

Hard (H) 1” to

5”/100

1 to 3 Rock can be scratched with fingernail

Gypsum, Calcite, Evaporites, Chalk, some Shale

Soft (So) 4” to

6”/100

BEDROCK HARDNESS

DESCRIPTION CONDITION

Absence of moisture, dusty, dry to touch

DRY

Damp but no visible water MOIST

Visible free water WET

MOISTURE CONDITION OF COHESIVE SOILS

U.S. STANDARD SIEVE SIZE(S)

6" 3" 3/4" 4 10 200

GRAVEL SAND

152 76.2 19.1 4.76 2.0 0.42 0.074 0.002

GRAIN SIZE IN MM

SILT OR CLAY CLAYFINE

40

COARSE FINE COARSE MEDIUMCOBBLESBOULDERS

SAMPLER TYPES SOIL TYPES

APPARENT DESNITY

SPT (BLOWS/FT)

CALIFORNIA SAMPLER

(BLOWS/FT)

MODIFIED CA. SMAPLER

(BLOWS/FT)

RELATIVE DENSITY (%)

Very Loose 0 to 4 0 to 5 0 to 4 0 to 15

Loose 4 to 10 5 to 15 5 to 12 15 to 35

Medium Dense 10 to 30 15 to 40 12 to 35 35 to 65

Dense 30 to 50 40 to 70 35 to 60 65 to 85

Very Dense >50 >70 >60 85 to 100

RELATIVE DENSITY FOR GRANULAR SOILS

ABBREVIATIONS

CLASSIFICATION OF GRANULAR SOILS

PL – Plastic Limit

LL – Liquid Limit

WC – Percent Moisture

QP – Hand Penetrometer

QU – Unconfined Compression Test

UU – Unconsolidated Undrained Triaxial

Note: Plot Indicates Shear Strength as Obtained By Above TestsINITIAL GROUND WATER

FINAL GROUND WATER

CONSISTENCY OF ROCK CORES

CONSISTENCY UNCONF. COMP.

STRENGTH IN TSF

Very Soft 10 TO 250

Soft 250 TO 500

Hard 500 TO 1000

Very Hard 1000 TO 2000

Extra Hard >2000


PROFESSIONAL SERVICE INDUSTRIES, INC.

APPENDIX B

Jff Information M[To Build On m

Engineering • Consulting • Testing

June 24, 2008

City of Denton 215 E. McKinney Street Denton, Texas 76201

Attention: Mr. Herman Lawson

RE: Addendum to Geotechnical Engineering Services Report Proposed Public Training Facility 4111 Vintage Boulevard Denton, Texas PSI Project No.: 342-85019 Addendum 1

Dear Mr. Lawson:

As requested by Mr. Roger LeBoeuf of Elliott, LeBoeuf & McElwain Engineering, Professional Service Industries, Inc. (PSI) is pleased to submit this addendum to our original geotechnical report for the above referenced project. This addendum report should be read in conjunction with our original geotechnical report dated April 8, 2008, and PSI report number 342-85019. Based on the new information provided by Mr. Roger LeBoeuf, maximum wall loads are 15 kips per linear foot, with typical wall loads between 4 laps per linear foot and 10 kips per linear foot. Maximum column loads are understood to be 360 kips. The structural systems are reinforced concrete slabs supported on load bearing masonry walls. Also, Mr. Roger LeBoeuf requested PSI to provide:

• A straight shaft driller pier recommendation ® The lateral load design parameters ® Pier uplift force resisting capacity to resist overturning loads ® Earth pressure and other design criteria for retaining walls • A reduced pier cluster spacing

Straight Shaft Drilled Pier Recommendations

Consideration may be given to supporting the building loads on straight shaft drilled piers as requested by Mr. Roger LeBoeuf. We understand that maximum column loads are 360 kips. Based on the subsurface conditions encountered, weathered gray shale was not present at all the boring locations and PSI strongly recommends verifying the depth to the weathered gray shale by performing two (2) additional deep borings to a minimum depth of 15 feet into the weathered gray shale or to a total depth of 55 feet. A minimum penetration of 15 feet into the weathered gray shale is recommended verify the bearing capacity of the weathered gray shale below the calculated pier penetrations.

Public Training Facility PSI Project No.: 342-85019 Addendum 1

June 24, 2008 Page 1 of 8

Professional Service Industries, Inc. • 4087 Shilling Way • Dallas, TX 75237 * Phone 214/330-9211 • Fax 214/333-2853

geotechnical engineering services report...1. classification (astm d 2487 / 2488) 2. moisture...

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