geotechnical engineering investigation · 2018. 1. 3. · engineering environmental (esa i & ii)...

Geotechnical Engineering Study Remuda Elementary 3400 North 3000 West

Farr West, UT

PREPARED FOR:

Scott Zellmer Director of Facilities and Operations

Weber School District 955 West 12th Street Ogden, Utah 84404

PREPARED BY:

CMT Engineering Laboratories

CMT Project No. 10001

August 9, 2017

ENGINEERING ENVIRONMENTAL (ESA I & II) MATERIALS TESTING SPECIAL INSPECTIONS ORGANIC CHEMISTRY

LOGAN OFFICE: 2005 NORTH 600 WEST, SUITE A, LOGAN, UTAH 84321 • TEL: (435) 753-6815 • FAX: (435) 787-4983 OGDEN OFFICE: 707 24th STREET, SUITE 1A, OGDEN, UTAH 84401 • TEL: (801) 870-6730

SALT LAKE CITY OFFICE: 2796 S. REDWOOD ROAD, SALT LAKE CITY, UTAH 84119 • TEL: (801) 908-5954 • FAX: (801) 972-9075 UTAH COUNTY OFFICE: 496 EAST 1750 NORTH, SUITE B, VINEYARD, UTAH 84057 • TEL: (801) 492-4132

ATL/ARIZONA OFFICE: 2921 NORTH 30th AVENUE, PHOENIX, ARIZONA 85017 • TEL: (602) 241-1097 • FAX: (602) 2771306 EMAIL = [email protected]

August 9, 2017 Scott Zellmer Director of Facilities and Operations Weber School District 955 West 12th Street Ogden, Utah 84404 Subject: Geotechnical Engineering Study Remuda Elementary 3400 North 3000 West Farr West, Utah CMT Engineering Project Number: 10001 Mr. Zellmer, Submitted herewith is the report of our geotechnical engineering study for the subject site. This report contains our findings and an engineering interpretation of the results with respect to the available project characteristics. It also contains recommendations to aid in the design and construction of the earth related phases of this project. On June 30, 2017, a CMT Engineering Laboratories (CMT) engineer was on-site and supervised the drilling of thirteen test borings extending approximately 5.5 to 51.5 feet below the existing grades. Soil samples were obtained during the field operations and were then transported to our laboratory where select samples were tested for pertinent engineering characteristics. Based on the findings of the subsurface explorations the site may be prepared for support of the proposed school by following the recommendations in the detailed discussion of design and construction criteria presented in this report. We appreciate the opportunity to work with you on this project. CMT offers a full range of Geotechnical Engineering, Geological, Material Testing, Special Inspection services, and Phase I and II Environmental Site Assessments. With 4 offices throughout Northern Utah, and in Arizona, our staff is capable of efficiently serving your project needs. If we can be of further assistance or if you have any questions regarding this project, please do not hesitate to contact us at (801) 492-4132. To schedule materials testing please call (801) 908-5859. Sincerely, CMT Engineering Laboratories

Jeffrey J. Egbert, P.E., LEED A.P., M. ASCE Bryan N. Roberts, P.E. Senior Geotechnical Engineer Senior Geotechnical Engineer

8/9/17

Table of Contents 1.0 INTRODUCTION ............................................................................................................................................ 1

1.1 Objectives and Scope.................................................................................................................................... 1 1.2 Authorization ................................................................................................................................................ 1

2.0 EXECUTIVE SUMMARY .............................................................................................................................. 2 3.0 PROPOSED CONSTRUCTION ...................................................................................................................... 3 4.0 SITE CONDITIONS AND FIELD INVESTIGATION ................................................................................... 3

4.1 General Geology .......................................................................................................................................... 3 4.2 Existing Surface Conditions ....................................................................................................................... 4 4.3 Field Exploration......................................................................................................................................... 6

4.3.1 Soil Observations ................................................................................................................................. 6 4.3.2 Infiltration Test .................................................................................................................................... 7

4.4 Sub-Surface Soils ......................................................................................................................................... 7 4.5 Ground Water ............................................................................................................................................... 7 4.6 Site Subsurface Variations ............................................................................................................................ 8 4.7 Seismic Setting ............................................................................................................................................. 9

4.7.1 Faulting ................................................................................................................................................. 9 4.7.2 Liquefaction .......................................................................................................................................... 9 4.7.3 Seismic Site Classification ................................................................................................................. 10 4.7.4 Ground Motions ................................................................................................................................. 10

5.0 LABORATORY TESTING ..................................................................................................................... 11 5.1 General ....................................................................................................................................................... 11 5.2 Natural Moisture Content ........................................................................................................................... 11 5.3 Atterberg Limits ......................................................................................................................................... 11 5.4 Consolidation Tests .................................................................................................................................... 12 5.4 Gradation Tests ........................................................................................................................................... 12

6.0 SITE PREPARATION AND GRADING ...................................................................................................... 13 6.1 General Site Grading ................................................................................................................................. 13 6.2 Excavations ............................................................................................................................................... 13 6.3 Fill Material ............................................................................................................................................... 14

6.3.1 Structural/Engineered Fill: ............................................................................................................... 14 6.3.2 Non-Structural Fill: ............................................................................................................................ 14

6.4 Trenches .................................................................................................................................................... 14 6.5 Fill Placement and Compaction ............................................................................................................... 15 6.6 Stabilization ............................................................................................................................................... 15

7.0 FOUNDATIONS ............................................................................................................................................ 16 7.1 Foundation Support .................................................................................................................................. 16 7.2 Estimated Settlement ............................................................................................................................... 18

8.0 LATERAL EARTH PRESSURES ..................................................................................................................... 18 9.0 FLOOR SLABS.............................................................................................................................................. 19 10.0 SURFACE DRAINAGE RECOMMENDATIONS ..................................................................................... 19 11.0 PAVEMENTS .............................................................................................................................................. 20

Pavement Design ........................................................................................................................................ 21 12.0 QUALITY CONTROL................................................................................................................................. 21

12.1 Field Observations .................................................................................................................................. 21 12.2 Fill Compaction ....................................................................................................................................... 22 12.3 Vibration Monitoring .............................................................................................................................. 22 12.4 Concrete and Asphalt Quality ................................................................................................................ 22

13.0 LIMITATIONS ............................................................................................................................................ 22 14.0 REFERENCES ............................................................................................................................................. 23

APPENDIX Figure 1: Vicinity Map Figure 3: Geologic Map Figure 17: Key to Symbols Figure 2: Site Map Figures 4-16: Boring Logs

Geotechnical Engineering Study Page 1 Remuda Elementary Farr West, Utah CMT Project No. 10001




ATL/ARIZONA OFFICE: 2921 NORTH 30th AVENUE, PHOENIX, ARIZONA 85017 • TEL: (602) 241-1097 • FAX: (602) 277-1306 EMAIL = [email protected]

1.0 INTRODUCTION CMT Engineering Laboratories (CMT) was retained by Mr. Scott Zellmer of Weber School District to conduct a geotechnical engineering study for the proposed construction of an elementary school to be located at about 3400 North 3000 West in Farr West, Utah (See Figures 1 and 2 in the Appendix).

1.1 Objectives and Scope The objectives and scope of our study were planned in communications between Mr. Skyler Rubel with MHTN Architects, Mr. Dustin Bay with Gardner Engineering, and Mr. Jeffrey Egbert of CMT Engineering Laboratories (CMT). In general, the objectives of this study were to:

1. Define and evaluate the subsurface soil and groundwater conditions across the site.

2. Provide appropriate foundation, earthwork, and pavement

recommendations and geoseismic information to be utilized in the design and construction of the proposed school.

In accomplishing these objectives, our scope has included the following:

1. A field program consisting of the drilling, logging, and sampling of 13 subsurface soil borings.

2. A laboratory testing program.

3. An office program consisting of the correlation of available data, engineering

analyses, and the preparation of this summary report.

1.2 Authorization Mr. Scott Zellmer with Weber School District authorized this study by signing our proposal dated June 20, 2017.






2.0 EXECUTIVE SUMMARY

Based upon the findings and results of our exploration and testing the most significant geotechnical aspects affecting the proposed construction at this site include:

1. Relatively shallow ground water. 2. Potentially liquefiable subsurface sand layers across the site.

Following is a brief summary of our findings and conclusions:

1. On the surface at the boring locations we encountered approximately 4 inches of natural clayey and sandy soil with roots and organic material (topsoil). Below the topsoil we encountered layers of relatively thin surficial clay overlying a moderately thick sequence of sand with varying silt content extending to about 25 feet below the surface underlain with silt and clay soil layers to the maximum depth penetrated, 51.5 feet.

2. Groundwater was initially encountered at depths of between 3 and 5.5 feet below the surface in the borings during drilling and later measured at depths ranging from 3.9 to 6.5 feet below the existing site grades.

3. Subsurface, saturated, sand layers appear to have a moderate to high susceptibility to liquefaction during the design earthquake. Our evaluation indicates that liquefaction related settlements could be on the order of 2 to 5 inches. Lateral spread displacement are estimated to be on the order of 2 to 3 inches. Liquefaction could also result in ground rupture at some locations and the liquefied sand soils “boiling” onto the surface. Potential liquefaction related differential movements can be reduced by using ground improvement methods such as rammed aggregate piers, or resisted by tying foundations together with reinforced grade beams.

4. Conventional footings tied with grade beams may be established on suitable, undisturbed, uniform natural soils, or entirely on a minimum zone of structural/engineered fill extending to suitable, undisturbed natural soils. A maximum allowable soil bearing pressure of 2,500 psf may be utilized for design of footings on the natural soils. If ground improvement methods are implemented such as rammed aggregate piers, a higher bearing pressure for conventional concrete spread footings is likely. Additionally, grade beams would likely not be necessary over improved ground.

5. Use of the natural sand soils as site grading fill below the building and pavements may be possible but additional testing would be required. These soils are likely above optimum moisture content currently and would require drying prior to re-utilization as structural fill. The natural clay soils may be utilized as site grading fill in playing field






and landscape areas but these soils will likely be difficult to control the moisture content needed for proper compaction.

3.0 PROPOSED CONSTRUCTION

We understand the proposed structure will be an elementary school, but no building details were available at the time this report was prepared. We project the building will be constructed slab on grade with masonry walls. We project that wall loads will not exceed 10,000 pounds per linear foot, column loads will not exceed 150,000 pounds, and uniform floor loads will not exceed 150 pounds per square foot. If actual foundation loads exceed these levels, additional recommendations will likely be required. We anticipate that utilities will be installed to service the school building and that asphalt concrete paved playground areas, drop-off lanes, driveways and parking areas will be constructed. We also anticipate that some minimal cutting and filling will take place across the site.

4.0 SITE CONDITIONS AND FIELD INVESTIGATION

Existing surface and subsurface conditions associated with the subject property are presented in this section.

4.1 General Geology The subject site is located in the north-central portion of Weber County in north-central Utah at an elevation of approximately 4,235 feet above sea level. The site is located in the northeast portion of a valley bound by the Wasatch Mountains on the east and Antelope Island (Great Salt Lake) and the Promontory Mountains to the west. The valley is a deep, sediment-filled basin that is part of the Basin and Range Physiographic Province. The valley was formed by extensional tectonic processes during the Tertiary and Quaternary geologic time periods. The Valley is located within the Intermountain Seismic Belt, a zone of ongoing tectonism and seismic activity extending from southwestern Montana to southwestern Utah. The active (evidence of movement in the last 10,000 years) Wasatch Fault Zone is part of the Intermountain Seismic Belt and extends from southeastern Idaho to central Utah along the western base of the Wasatch Mountain Range. Much of northwestern Utah, including the valley in which the subject site is located, was also previously covered by the Pleistocene age Lake Bonneville. The Great Salt Lake, located along the western margin of the valley and beyond, is a remnant of this ancient fresh water






lake. Lake Bonneville reached a high-stand elevation of approximately 5,092 feet above sea level at between 18,500 and 17,400 years ago. Approximately 17,400 years ago, the lake breached its basin in southeastern Idaho and dropped by almost 300 feet relatively fast as water drained into the Snake River. Following this catastrophic release, the lake level continued to drop slowly over time, primarily driven by drier climatic conditions, until reaching the current level of the Great Salt Lake. Shoreline terraces formed at the high-stand elevation of the lake and several subsequent lower lake levels are visible in places on the mountain slopes surrounding the valley. Much of the sediment within the Valley was deposited as lacustrine sediments during both the transgressive (rise) and regressive (fall) phases of Lake Bonneville. A geologic map that includes the location of the subject site has been completed by Harty and others1. The surficial geology over the majority of the location of the subject site and adjacent properties is mapped as “Lacustrine fine-grained deposits” (Map Unit Qlf) dated to be Holocene to upper Pleistocene. On the western portion of the site deposits mapped as “Marsh deposits” (Map Unit Qsm) are shown at the surface. Unit Qsm is dated as Holocene. No fill has been mapped at the location of the site on the geologic map. Unit Qlf is described on the referenced map as “Intervals of mixed fine-grained sediment, clay to silt, and intervals of rhythmically interbedded fine to medium sand; commonly calcareous; typically laminated or thin bedded; deposited in low-energy, generally offshore environments at elevations below the Provo shoreline; thickness typically less than 5 meters (15 ft).” Unit Qsm is described as “Wet, fine-grained, organic-rich sediment associated with springs and seeps; thickness probably less than 1 meter (3 ft) in most areas.” Refer to Figure 3, Geologic Map. No surface fault traces are shown on the referenced geologic map crossing, adjacent to, or projecting toward the subject site. No landslide deposits or features, including lateral spread deposits, are mapped on or adjacent to the site. The site is not located within a known or mapped potential debris flow, stream flooding, or rock-fall hazard area.

4.2 Existing Surface Conditions At the time the subsurface explorations were performed the site consisted of an undeveloped alfalfa field (see photo 1 below). The site appears to have been cultivated in the past. Site grade drops slightly downward to the south and west. Based upon aerial photographs readily available on-line, dating back to 1993, the site appears to have been an open field since that time. The site is bound on the north and east by single family residential developments, on the south by an open, unlined canal (see photo 2 below), and on the west by a field (see Figures 1 and 2 in the Appendix). 1Harty, K.M., Lowe, M., and Kirby, S.M., 2012, Geologic Map of the Plain City Quadrangle, Weber and Box Elder Counties, Utah; Utah Geological Survey Map 253DM, Scale 1:24,000.






Photo 1. Looking west across the site.

Photo 2. Existing canal along the south end of the site. Flowing water was present at time of drilling.






4.3 Field Exploration 4.3.1 Soil Observations The subsurface soil conditions were observed by drilling thirteen (13) test borings at the approximate locations shown on Figure 2 in the Appendix. The borings extended approximately 4.5 to 51.5 feet below the existing grades. Samples of the subsurface soils encountered in the borings were collected at varying depths through the hollow stem drill augers. During the course of the drilling operations, a continuous log of the subsurface conditions encountered was maintained. The field portion of our study was performed under the direct control and continual supervision of an experienced member of our geotechnical staff. In addition, samples of the typical soils encountered were obtained for subsequent laboratory testing and examination. The subsurface conditions encountered in the explorations are discussed in Section 4.4, below. A 3.25-inch outside diameter, 2.42-inch inside diameter drive sampler (Dames & Moore) and a 2.0-inch outside diameter, 1.38-inch inside diameter drive sampler (SPT) were utilized for subsurface sampling at select locations. The blow counts recorded on the boring logs were those required to drive the sampler 12 inches with a 140-pound hammer dropping 30 inches. The blow count provides a reasonable approximation of the relative density of granular soils, but only a limited indication of the relative consistency of fine grained soils because the consistency of these soils is significantly influenced by the moisture content. The collected samples were logged and described in general accordance with ASTM 2488, packaged, and transported to our laboratory. The soils were classified in the field based upon visual and textural examination. These classifications have been supplemented by subsequent inspection and testing in our laboratory. Detailed graphical representations of the subsurface conditions encountered are presented on Figures 4 through 16, Bore Hole Log provided in the Appendix. Sampling information and other pertinent data and observations are also included on the logs. In addition, a Key to Symbols defining the terms and symbols used on the logs is provided as Figure 17 in the Appendix. Following completion of drilling operations, 1.25-inch diameter slotted PVC pipe was installed in 9 of the bore holes in order to provide a means of monitoring the groundwater fluctuations. The borings were backfilled with auger cuttings.






4.3.2 Infiltration Test To assess the water infiltration rate of the natural soils an infiltration test was performed in boring B-2. The hole was extended to a depth of 1.5 feet below the surface into the near surface clay soil. The hole was filled with water and the drop in water level over time was measured and a rate of infiltration was calculated. The final calculated rate was on the order of approximately 15 minutes per inch. Due to siltation and the introduction of possible debris and other deposits over time we recommend an infiltration rate of 30 minutes per inch be utilized for the natural clay soils at the site.

4.4 Sub-Surface Soils On the surface at the boring locations we encountered natural clayey and sandy soils with roots and organic material (topsoil) extending about 4 inches in depth. Where the site has been cultivated in the past disturbed soils and/or organic material may extend deeper. Below the topsoil a layer of silty/fine sandy CLAY (CL) was encountered at borings B-1 through B-3, B-5 through B-8, B-10, and B-11 extending about 1.0 to 3.5 feet below the surface. Below this surficial clay layer at the above boring locations and from the surface at the remaining boring locations we predominately encountered layers of natural, moist to wet, brown to gray SILTY/GRAVELLY SAND (SM/SP), SILTY SAND (SM), and Fine SAND (SP) extending as deep as 25 feet below the ground surface at Boring B-10. Based upon the blow counts the sand layers had relative densities which ranged from loose to medium dense. Due to the shallow groundwater many of the sand layers encountered are potentially liquefiable during the design earthquake. See Section 4.7.2, Liquefaction for additional information. In the deeper boring, B-10, below the sand at about 25 feet we encountered a layer of soft to medium stiff SILT (ML) extending to about 35 feet below the surface underlain by a deeper layer of clay extending to the full depth penetrated, about 51.5 feet below the surface. For a detailed description of the soil profiles encountered in each exploration see the exploration logs (Figures 4 through 16) in the Appendix. Sampling information and other pertinent data and observations are also included on the logs. In addition, a Key to Symbols sheet defining the terms and symbols used on the logs, is provided as Figure 17 in the Appendix. See Figure 2 for approximate exploration locations.

4.5 Ground Water Groundwater was encountered in each boring during drilling. Slotted PVC pipes were placed in several of the borings prior to backfilling in order to provide a means for measuring groundwater levels at a later time when water levels had stabilized. Accordingly we returned






to the site on July 17, 2017, approximately 17 days after drilling, and measured groundwater levels within installed PVC pipes. A summary of groundwater elevations is presented in the following table.

Boring No.

Groundwater Depth (feet)

June 30, 2017* July 17, 2017 B-1 4 No pipe installed B-2 4 Pipe not found B-3 4.5 No pipe installed B-4 5 No pipe installed B-5 4.5 No pipe installed B-6 3 3.9 B-7 4.5 4.25 B-8 3.5 4.4 B-9 3.5 3.9

B-10 3 Pipe not found B-11 3.5 5.75 B-12 5.5 6.6

B-13 4.5 Pipe plugged at 4 feet, no water to that depth *During drilling, not stabilized Groundwater levels often fluctuate as much as 1.5 to 2 feet seasonally. Numerous other factors such as heavy precipitation, flow in the adjacent canal, irrigation of neighboring land, and other unforeseen factors, may also influence ground water elevations at the site. The detailed evaluation of these and other factors, which may be responsible for ground water fluctuations, is beyond the scope of this study. Groundwater will most likely be encountered in utility trench excavations, and could possibly be encountered in footing excavations on portions of the site, depending on final grades. Piping the canal where it borders the site could have an influence on groundwater levels at the site but the piping would most likely need to extend much further east and west of the site.

4.6 Site Subsurface Variations Based on the results of the subsurface explorations, and our experience, variations in the continuity and nature of subsurface conditions should be anticipated. The boundaries between the various soil layers shown on the boring logs are approximate, the actual






transitions may be gradual. Due to the heterogeneous characteristics of natural soils, care should be taken in interpolating or extrapolating subsurface conditions between or beyond the exploratory locations. Seasonal fluctuations in ground water conditions may also occur.

4.7 Seismic Setting 4.7.1 Faulting As stated in Section 4.1, General Geology, not surface fault traces are mapped on or adjacent to the site. The nearest mapped fault trace considered to be active is associated with the Brigham City Segment of the Wasatch Fault and is located approximately 2 miles northeast of the site. The Wasatch Fault is considered a “normal” fault because movement along the fault is typically vertical. The east side of the fault, or the mountain block, typically moves upward relative to the valley block on the west side of the fault. The fault generally dips to the west below the valleys. In an earthquake, the point where the fault initially ruptures is called the ‘focus” and generally occurs about 10 miles below the surface. The point on the surface directly above the focus, the epicenter, typically out in the valley, is usually where the strongest ground shaking occurs. The Wasatch Fault is one of the longest and most active normal faults in the world. 4.7.2 Liquefaction The site is mapped by the Utah Geological Survey within an area designated as having “High” liquefaction potential. Liquefaction of a soil is defined as the condition when saturated, loose, cohesion-less, (sand-type) soils have a sudden, large decrease in their ability to support loads. This occurs because the ground shaking associated with a seismic event increases the water pressures between soil particles pushing them apart. Cohesive (clay type) soils typically do not liquefy during a seismic event. We encountered near surface sand layers, and at some boring locations surface sand layers, which appear to have loose to medium dense relative densities. We also encountered shallow groundwater (3.9 to 6.6 feet below the surface) across the site. We assessed the liquefaction potential of the subsurface soils using methodologies described in Soil Liquefaction during Earthquakes Monograph by Idriss and Boulanger 2014 and a peak ground acceleration for the site of 0.62 g, which is adjusted for Site Class D. The result of our assessment indicate a potential for between 2 and 5 inches of liquefaction related settlement near the surface of the site. Liquefaction could also result in ground rupture and the liquefied sand soils “boiling” onto the surface.






Another hazard associated with liquefaction is a potential for the liquefied soil to “flow” latterally, known as lateral spread. Based upon methods developed by Youd, et. al. (2002) we estimate that 2 to 3 inches of lateral spread displacement could occur if the near surface sand layers liquefy during the design seismic event. Methods for reducing the potential for liquefaction related differential movements include tying footings together with reinforced grade beams so that the foundation system performs more as a unit, or by reducing the potential for the subsurface soils to liquefy by ground improvement such as rammed aggregate piers. These are discussed in Section 7.0, Foundations. 4.7.3 Seismic Site Classification Our assessments indicate that the subsurface sand layers encountered in most of the borings could liquefy during the design seismic event (see Section 4.7.2, “Liquefaction” above). According to the IBC 2015, which references ASCE-7-10, Chapter 20, “Soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils...” are designated under site Class F. If ground improvement is performed in accordance with the specifications we have provided, and the potential settlements due to liquefaction are reduced to about 2.0 inches or less, this magnitude of settlement can typically be tolerated by an adequately designed structure to protect life safety. Therefore, it is our opinion that for dynamic structural analysis, the Site Class D – Stiff Soil Profile, as defined in Chapter 20 of ASCE 7 (per Section 1613.3.2, Site Class Definitions, of IBC 2015) can be utilized for footings constructed over improved ground. If ground improvement is not performed we recommend that a site specific seismic evaluation be performed by conducting a seismic cone penetration test. 4.7.4 Ground Motions The IBC 2015 code is based on 2008 USGS mapping, which provides values of short and long period accelerations for the Site Class B boundary for the Maximum Considered Earthquake (MCE). This Site Class B boundary represents average bedrock values for the Western United States and must be corrected for local soil conditions. The following table summarizes the peak ground and short and long period accelerations for the MCE event and incorporates the appropriate soil amplification factor for a Site Class D soil profile. Based on the site latitude and longitude (41.322 degrees north and -112.053 degrees west, respectively), the values for this site, based upon Site Class D for improved subsurface soils, are tabulated below:






SpectralAcceleration

Value, TPeak Ground Acceleration Fa = 1.000

0.2 Seconds (Short Period Acceleration)

SS = 153.9 Fa = 1.000 SMS = 153.9 SDS = 103

1.0 Second (Long Period Acceleration)

S1 = 52.0 Fv = 1.500 SM1 = 78 SD1 = 52

Site Class B

SiteCoefficient

DesignValues(% g)41.161.6

(% g)mapped values

BoundarySite Class D

61.6(% g)

class effects][adjusted for site

5.0 LABORATORY TESTING

5.1 General In order to provide data necessary for our engineering assessments, a laboratory testing program was performed. The program included natural moisture content tests, Atterberg limits, one-dimensional consolidation, and mechanical gradations. The following paragraphs describe the tests and summarize the test data.

5.2 Natural Moisture Content To assess the moisture content of the natural soils moisture tests were performed on selected undisturbed samples. The results of these tests are presented on the boring logs. 5.3 Atterberg Limits To aid in classifying the soils, Atterberg limit tests were performed on select samples of the fine-grained soils. Results of the tests are tabulated in the table on the following page:






Boring No.

Depth (feet)

Liquid Limit

(percent)

Plastic Limit

(percent)

Plasticity Index

(percent) Soil

Classification

B-2 0 28 20 8 CL

B-6 2 38 22 16 CL

B-10 25 25 22 3 ML

B-10 30 29 25 4 ML

B-10 45 38 20 18 CL 5.4 Consolidation Tests To provide data necessary for our settlement analyses, a consolidation test was performed on each of two representative samples of the near surface clay soils encountered in the exploration borings. The results of these tests indicate that the clays are over consolidated and will exhibit moderate compressibility. Detailed results of the tests are maintained within our files and can be transmitted to you, at your request.

5.4 Partial Gradation Tests Partial gradation tests were performed to aid in classifying soils. The tests results are tabulated below:

Boring No.

Depth (feet)

Percent Passing

Sieve Soil

Classification No. 4

No. 200

B-3 8 100 2 SP

B-7 8 99 3 SP

B-8 14 100 2 SP

B-11 9.5 100 5 SP-SM

B-12 2 99 47 SM






6.0 SITE PREPARATION AND GRADING

6.1 General Site Grading Initial site preparation will consist of the removal of surface vegetation, topsoil, non-engineered fills (if encountered) and any other deleterious materials, from beneath an area extending out at least 4 feet from the perimeter of the proposed building and 2 feet beyond pavements and exterior flatwork areas. Vegetation and other deleterious materials should be removed from the site. Topsoil, although unsuitable for utilization as structural fill, may be stockpiled for subsequent landscaping purposes. At the boring locations we encountered clayey sandy soils with roots and organic material on the surface approximately 4 inches in thickness. In general, we estimate that grubbing of the upper 4 to 6 inches of the surface will remove the most significant zone of roots and organic material. Where the site has been cultivated in the past, loose or disturbed soils and/or organic material may extend deeper. Site grubbing and excavations should be examined by a CMT geotechnical engineer to assess if all deleterious materials/unsuitable soils have been removed from beneath the proposed structure prior to placement of fill materials or forming for footings. Fill placed over large areas to raise overall site grades can induce settlements in the underlying natural soils. If more than 3 feet of site grading fill is anticipated to be placed over the existing surface of any portion of the site we should be notified to assess potential settlements and provide additional recommendations as needed. These recommendations may include placement of the site grading fill far in advance to allow potential settlements to occur prior to construction.

6.2 Excavations For temporary excavations less than 5 feet deep, either in the native soils or structural fill and above the groundwater, slopes should not be steeper that 0.5:1 (horizontal to vertical). Excavations encountering saturated cohesionless soils will be very difficult and will require very flat sideslopes and/or shoring, bracing and dewatering. All excavations should be made following OSHA safety guidelines.






6.3 Fill Material The natural soils were found to predominately consist of sands with a low fines content. It may be possible to utilize these soils as site grading fill below the building and pavements but these soil may be very moist to wet and require some drying prior to re-utilization. The natural clay soils should not be used as site grading fill in structurally loaded areas but could be utilized as site grading fill in playing field and landscape areas. The natural clay soils will be difficult to rework due to problems controlling the moisture content needed for proper compaction. The following types of fill are recommended for their specific applications: 6.3.1 Structural/Engineered Fill: Fill utilized below the building, exterior concrete flatwork, and pavements should be composed of a well-graded granular soil free of organics, debris, or other deleterious materials. Generally, we recommend a well-graded mixture of sands and gravels with no more than 20 percent fines (material passing the No. 200 sieve) and no more than 30 percent retained on the three-quarter-inch sieve. 6.3.2 Non-Structural Fill: Non-structural site grading fill is defined as all fill material not designated as structural fill and may consist of any cohesive or granular soils not containing excessive amounts of degradable material. The natural soils may be very difficult to work with, particularly in colder/wetter seasons.

6.4 Trenches Most utility companies and City-County governments are now requiring that Type A-1a or A-1b (AASHTO Designation – basically granular soils with limited fines) soils be used as backfill over utilities. These organizations are also requiring that in public roadways the backfill over major utilities be compacted over the full depth of fill to at least 96 percent of the maximum dry density as determined by the AASHTO T-180 (ASTM D-1557) method of compaction. In private utility areas, natural soils may be re-utilized as trench backfill over the bedding layer provided that they are properly moisture prepared and compacted to the minimum requirements stated in section 6.5 Fill Placement and Compaction below.






6.5 Fill Placement and Compaction The various types of compaction equipment available have their limitations as to the maximum lift thickness that can be compacted. For example, hand operated equipment (jumping jack) is limited to lifts of about 4 inches and most “trench compactors” have a maximum, consistent compaction depth of about 6 inches. Large rollers, depending on soil and moisture conditions can achieve compaction at 8 to 12 inches. For fill depths not exceeding 5 feet the full thickness of each lift should be compacted to at least the following percentages of the maximum dry density as determined by ASTM D-1557:

Location

Total Fill Thickness

(feet)

Minimum Percentage of Maximum Dry

Density Beneath an area extending at least 4 feet beyond the perimeter of the structure 0 to 5 95

Site grading fills outside area defined above 0 to 5 92

Utility trenches within structural areas -- 96

Roadbase/Subbase - 96 Subsequent to stripping and prior to the placement of structural site grading fill, the subgrade shall be prepared as discussed in Section 6.1, Site Preparation, of this report. In confined areas, subgrade preparation should consist of the removal of all vegetation, topsoil, and loose or disturbed soils. Field density tests should be performed on each lift as necessary to ensure that compaction is being achieved. As a minimum, 33% of all spot footings, and one test for every 50 lineal feet of continuous wall footings shall be tested for each lift.

6.6 Stabilization The natural near surface clay soils will easily rut and pump when wet. The likelihood of disturbance or rutting and/or pumping is a function of the load applied to the surface, as well as the frequency of the load and moisture content. Consequently, rutting and pumping can be minimized by avoiding concentrated traffic, minimizing the load applied to the surface by using lighter equipment and/or partial loads, by working in drier times of the year, or by






providing a working surface for the equipment. Rubber-tired equipment particularly, because of high pressures, promotes instability in wet, soft soils. If rutting or pumping occurs, traffic should be stopped and the disturbed soils should be removed and replaced with granular material. Typically a minimum of 18 inches of the disturbed soils must be removed to be effective. However, deeper removal is sometimes required. The most effective granular material for stabilization is a clean angular, well-graded gravel such as a pit run or crushed rock with a maximum size of about four inches. We suggest that the initial lift be approximately 12 inches thick and be compacted with a static roller-type compactor. The more angular and coarse the material, the thinner the lift that will be required. Often the amount of granular material can be reduced with the use of a geotextile fabric such as Mirafi RS280i or equivalent. Its use will also help avoid the mixing of the subgrade soils with the granular material. After the excavation of the disturbed soils, the fabric should be spread across the bottom of the excavation and up the sides a minimum of 18 inches. Otherwise, it should be placed in accordance with the manufacturer’s recommendation, including proper overlaps. The granular material can then be placed over the fabric in compacted lifts as described above.

7.0 FOUNDATIONS

The following recommendations have been developed on the basis of the previously described project characteristics and projected foundation loads discussed in Section 3.0 of this report, on the findings of the subsurface explorations, the results of the laboratory testing, and on common engineering practice in this area at this time.

7.1 Foundation Support As previously discussed, there is a moderate to high potential for the subsurface sand layers to liquefy during the design seismic event. Liquefaction could results in an estimated 2 to 5 inches of differential settlement, and 2 to 3 inches of lateral spread as well as isolated areas of ground rupture. To reduce the potential for liquefaction related differential movement’s conventional foundations could be tied together with a series of reinforced grade beams. Grade beams can facilitate the foundation system acting as a unit. A structural engineer should be consulted to assess if grade beams can provide sufficient resistance to the estimate liquefaction related differential movements and life safety to building occupants. Conventional footings supporting loads not exceeding those specified in Section 3.0, Proposed






Construction, and tied with grade beams, may be established on suitable, undisturbed, uniform natural sand soils or entirely on granular structural replacement fill extending to natural sand soils. A maximum allowable soil bearing pressure of 2,500 psf may be utilized for design of conventional footings. The general design recommendations for conventional foundations given below should also be followed:

• Unsuitable soils including topsoil, organic soils, loose or disturbed soils, debris, or any other deleterious materials must be removed from below the building footprint to the placement of foundations or structural fill.

• To reduce the potential for differential settlement we recommend that footings not be supported on cut/fill transitions or on clay/sand combinations. Where this is anticipated all footings should be underlain by a minimum zone of structural fill equivalent to 1/3 the maximum depth of required fill under any other portion of the foundation. For example if 6 feet of structural fill is required under footings on one portion of the site, a minimum of 2 feet of structural fill should be placed below all remaining footings.

• Footing areas should be excavated using a cutting bar or other smooth-bladed equipment to minimize disturbance to the underlying soils.

• Base soil should be examined by a CMT geotechnical engineer to assess if suitable bearing soils have been exposed.

• All imported structural fill should be placed and compacted in accordance to Section 6.3

• Continuous footing width should be a minimum of 20 inches. • Spot footings should be a minimum of 30 inches in width. • Exterior footings should be placed a minimum of 30 inches below final grade and

interior footing shall be placed a minimum of 12 inches below grade. The allowable bearing pressure may be increased by 1/3 for temporary loads such as wind and seismic forces. Another method for reduction of the potential liquefaction related movements is by reducing the potential for the subsurface soils to liquefy by ground improvement such as rammed aggregate piers. A number of local contractors perform ground improvement. Ground improvement methods are typically a design build process. As a minimum we recommend that ground improvement elements be placed in a grid pattern with each element extended at least 15 feet below bottom of floor slab, and a minimum of 20 feet below all footings to reduce potential liquefaction related settlement to less than 2 inches. We recommend that spacing of the ground improvement elements be such that a minimum






SPT blow count of between 15 and 20 blows per foot be provided for the improved natural soils between pier elements. The selected ground improvement contractor will determine spacing and any potential increase in bearing pressure. We can provide contact information for local ground improvement contractors if desired.

7.2 Estimated Settlement Foundations designed and constructed in accordance with our recommendations could experience some settlement. If the recommendations in this report are followed we estimate that static settlement should not exceed 1 inch with differential settlements estimated to not exceed ½ inch. Additional settlement could occur if foundation loads exceed the maximum levels we have projected. As discussed in Section 4.7.2, Liquefaction, the subsurface sand layers are potentially liquefiable during the design seismic event. We estimate that liquefaction could result in additional differential settlement between about 2 to 5 inches unless ground improvement methods are implemented.

8.0 LATERAL EARTH PRESSURES It is anticipated that the structure will be primarily slab on grade. However, the following discussion is for subgrade walls, utilities etc., extending about 4 feet below the surface. We predominately encountered natural sand soils in the borings. We anticipate these soils would be utilized as backfill against foundations. For these soils the following lateral soil pressures should be used for design:

1. An equivalent fluid pressure of 38 pounds per cubic foot (pcf) for the active case. That is when the structure is allowed to yield, i.e. move away from the soil. This requires a minimum movement or rotation at the top of the wall of 0.001H, where “H” is the height of the wall (bottom of footing to top of wall).

2. 59 pcf for the at rest case. This case occurs when the wall is not allowed to yield. 3. 300 pcf for the passive case. In this situation, the wall moves into the soil. For seismic loading of retaining/below-grade walls, the following uniform lateral pressures, in pounds per square foot (psf), should be added based on wall depth and wall case:






Uniform Seismic Lateral Pressures Wall Height

(Feet) Active Pressure Case

(psf) At Rest/Non-Yielding

Case (psf)

4 39 104

If imported soils are used as backfill, we recommend that this office review the materials and determine if the above design earth pressures are still appropriate.

9.0 FLOOR SLABS Floor slabs with uniform floor loads not exceeding those we have projected may be supported on suitable, undisturbed natural soils, or entirely on structural/engineered fill. If ground improvement is selected for reducing the potential for liquefaction related movements we anticipate that a working “mat” of structural fill will be placed to aid the ground improvement process. To aid in distributing the floor loads and to create a capillary break, we also recommend that all slabs, including exterior flatwork, be underlain by a minimum of 4 inches of free draining granular material. To help control normal shrinkage and stress cracking, the floor slabs should have the following features:

1. Adequate reinforcement for the anticipated floor loads with the reinforcement continuous through interior floor joints;

2. Frequent crack control joints; and 3. Non-rigid attachment of the slabs to foundation walls and bearing slabs.

10.0 SURFACE DRAINAGE RECOMMENDATIONS

We recommend that the following actions be completed to facilitate surface water being directed away from the foundation bearing soils:

1. All areas around the building should be sloped to provide drainage away from the foundation. We recommend a minimum slope of 6 inches in the first 10 feet away






from the structure. This slope should be maintained throughout the lifetime of the structure.

2. All roof drainage should be collected in rain gutters with downspouts designed to

discharge at least 10 feet from the building, or well beyond the backfill limits, whichever is greater.

3. Adequate compaction of the foundation backfill should be provided. We suggest a

minimum of 90% of the maximum laboratory density as determined by ASTM D-1557. Water consolidation methods should not be used under any circumstances.

4. Sprinklers should be aimed away from the foundation walls. The sprinkling systems

should be designed with proper drainage and be well-maintained. Over watering should be avoided.

5. Other precautions may become evident during construction.

11.0 PAVEMENTS

We project that asphalt concrete paved drop-off lanes, driveways, parking areas and playground areas will be constructed as part of the development. Pavement design is dependent upon traffic volume and vehicle types. We project that the natural near surface clay soils will exhibit poor pavement support capabilities when saturated or nearly saturated. For the natural near surface clay soils at the school site we estimate a CBR value of 3. We project that playground areas will have very light, if any, vehicular traffic, and parking areas and student drop off lanes will have a light to moderate traffic load of 3 equivalent 18-kip single axel loads (EASL’s) per day. The entrance driveway, bus lanes, fire lane and service yard areas will have a moderate to heavy traffic load of 8 equivalent 18-kip axel loads per day. The following minimum pavement sections are recommended as shown in table on the following page:






Pavement Design

Material

Pavement Section

Thickness (in) Playground

Areas

Pavement Section

Thickness (in) Parking Areas/

Student Drop Off

Pavement Section Thickness (in)

Entrance Driveway Bus Drop Off Service Yard

Fire Lane Asphalt 2 3.5 4 Road-Base 6 8 6 Sub-base 0 0 6 Total Thickness 8 11.5 16

Sub base should consist of granular soils that meet the specification for structural fill given in this report and have a minimum CBR of 30 percent. Untreated base course (UTBC) should conform to city or 1-inch-minus UDOT specifications for A-1-a/NP and have a CBR value greater than 70%. Asphalt should conform to the standard city or UDOT specification. All engineered fill materials used in pavement areas should be compacted in accordance with Section 6.5 of this report. The asphalt pavement should be compacted to 96% of the maximum density for the asphalt material. If soft soils are encountered, additional sub-base and/or a stabilization fabric may be required to provide a stable surface for the remainder of the pavement materials.

12.0 QUALITY CONTROL We recommend that CMT be retained as part of a comprehensive quality control testing and observation program to help facilitate implementation of our recommendations and to address, in a timely manner, any subsurface conditions encountered which vary from those described in this report. Without such a program CMT cannot be responsible for application of our recommendations to subsurface conditions which may vary from those described herein. This program may include, but not necessarily be limited to, the following:

12.1 Field Observations Observations should be completed during all phases of construction such as site preparation, foundation excavations, structural fill placement, etc.






12.2 Fill Compaction Compaction testing by CMT is required for all structural supporting fill materials. Maximum Dry Density (Proctor-ASTM 1557) tests should be requested by the contractor immediately after delivery of any granular fill materials. The maximum density information should then be used for field density tests on each lift as necessary to insure that the required compaction is being achieved.

12.3 Vibration Monitoring Construction activities, particularly site grading and fill placement, can induce vibrations in existing structures adjacent to the site. Such vibrations can cause damage to adjacent buildings, depending on the building composition and underlying soils. It can be prudent to monitor vibrations from construction activities to maintain records that vibrations did not exceed a pre-defined threshold known to potentially cause damage. CMT can provide this monitoring if desired.

12.4 Concrete and Asphalt Quality We recommend that freshly mixed concrete and asphalt be tested by CMT in accordance with all applicable standards.

13.0 LIMITATIONS The recommendations provided herein were developed by evaluating the information obtained from the subsurface explorations. The subsurface exploration logs reflect the subsurface conditions only at the specific location at the particular time designated on the logs. Soil and ground water conditions may differ from conditions encountered at the actual exploration locations. The nature and extent of any variation in the explorations may not become evident until during the course of construction. If variations do appear, it may become necessary to re-evaluate the recommendations of this report after we have observed the variation. Our professional services have been performed, our findings obtained, and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices. This warranty is in lieu of all other warranties, either expressed or implied.






We appreciate the opportunity to be of service to you on this project. CMT offers a full range of Geotechnical Engineering, Geological, Material Testing, Special Inspection services, and Phase I and II Environmental Site Assessments. With 4 offices throughout Northern Utah, and in Arizona, our staff is capable of efficiently serving your project needs. If we can be of further assistance or if you have any questions regarding this project, please do not hesitate to contact us at (801) 492-4132. To schedule materials testing please call (801) 908-5859.

14.0 REFERENCES ASTM, American Society for Testing and Materials 2010 Harty, K.M., Lowe, M., and Kirby, S.M., 2012, Geologic Map of the Plain City Quadrangle, Weber and Box Elder Counties, Utah; Utah Geological Survey Map 253DM, Scale 1:24,000. Liquefaction Special Study Areas, Wasatch Front and Nearby Areas, Utah Geological Survey, 2008 IBC, International Building Code, 2015 Edition, International Conference of Building Officials, Whittier, CA.

Appendix

Date:Job #

Figure:

1Vicinity MapRemuda Elementary School3400 N 3000 W, Farr West, UT 11-Jul-1710001

N

SITE

Date:Job #

Remuda Elementary School Figure:23400 N 3000 W, Farr West, UT Site Map 11-Jul-1710001

B-3

B-2B-1 B-4

B-5

B-6

B-7

B-8B-9

B-10

N

GroundwaterDepth (feet)6/30/17

4.5'

B-11B-12

B-13

5.5'

3.5'

3.5'

3.0'

3.5'

4.5'

3.0'

4.5'

5.0'

4.5'

4.0'4.0'

Date:Job #

Remuda Elementary School Figure:33400 N 3000 W, Farr West, UT Geologic Map 11-Jul-1710001

N

SITE

CLAY (CL) loosewith some fine sand; major roots (topsoil) to 4"; brown slightly moistSILTY SAND/SAND (SM/SP) moist 4fine grained; with some silt; cementation; brown medium dense 1 7 27

20

grades fine sand with trace to some silt saturated 42 9 16

7End at 5.5'

Remarks:

Excavated By:Logged By:

Page:4

Bore Hole Log B-1

Figure:

Remuda Elementary School Date:Total Depth:3400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger

Job #:5.5'4'

6/30/17

Groundwater encountered during drilling at depth of 4 feet.

Water Depth:

Soil DescriptionBlows (N)

Surface Elev. (approx): 10001

Great Basin DrillingRobert Grenda

1 of 1

Gradation Atterberg

0

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)

Dry

Den

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(pcf

)

Gra

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Sand

%

Fine

s %

LL PL PI

CLAY (CL) with some fine sand; major roots (topsoil) to 4"; brown slightly moist 4

to moist 3 9 18 10.9 28 20 8very stiff 9

SILTY SAND/ GRAVELLY SAND (SM/SP) fine grained; with trace to some silt; cementation; brown

very moist 7medium dense 4 11 20

saturated 9End at 4.5'

Remarks:


Page:

Remuda Elementary School Bore Hole Log B-26/30/17

Surface Elev. (approx): 3400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 4.5' Date:

Soil DescriptionBlows (N) Gradation Atterberg

Water Depth: 4' Job #: 10001

Groundwater encountered during drilling at depth of 4 feet. Figure:Slotted PVC pipe installed to depth of 4.5'

5Great Basin DrillingRobert Grenda1 of 1

0

4

8

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Dep

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Type

Sam

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)

Dry

Den

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(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

CLAY (CL) with some fine sand; major roots (topsoil) slightly moistto 4"; brown

moist 4stiff 5 6 14

8

SAND (SP) fine grained; brown grading gray saturated

medium dense 106 9 14

5

3grades with trace silt loose 7 4 8 25 0 98 2

4

18 2 4

2End at 11.5'

Remarks:


Page:




Water Depth: 4.5' Job #: 10001

Groundwater encountered during drilling at depth of 4.5 feet. Figure:


0

4

8

12

16

20

24

28

Dep

th (f

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GR

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Sam

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Type

Sam

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#

Tota

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stur

e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

SILTY SAND (SM) loose to 6" fine grained; with thin interbedded clay layers up to 1" thick;major roots (topsoil) to 4"; brown

moist 8medium dense 9 10 26

16

saturated 9grades with medium to coarse sand and clay loose 10 9 15layers up to 2" thick 6

FINE SAND (SP) gray saturated 1

loose 11 1 1110

15medium dense 12 23 53

30End at 11'

Remarks:


Page:


Surface Elev. (approx): 3400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 11' Date:


Water Depth: 5' Job #: 10001

Groundwater encountered during drilling at depth of 5 feet. Figure:


0

4

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12

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20

24

28

Dep

th (f

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GR

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Sam

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Type

Sam

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Moi

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)

Dry

Den

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(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

CLAY (CL) with some fine sand; major roots (topsoil) slightly moist 7to 4"; brown very stiff 13 9 23

14

SAND (SP) fine grained; with trace to some silt; brown 4

very moist 14 8 19medium dense 11

End at 4.5'

Remarks:


Page:




Water Depth: 4.5' Job #: 10001

Groundwater encountered during drilling at depth of 4.5 feet. Figure:


0

4

8

12

16

20

24

28

Dep

th (f

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GR

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G

Sam

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Type

Sam

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#

Tota

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Moi

stur

e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

CLAY (CL) loose to 6" with some fine sand, trace gravel; major roots (topsoil) to 4"; brown

moiststiff 5

15 7 21 23.8 98.2 38 22 16FINE SAND (SP) saturated 14gray

3loose 16 6 14

8


16

6 grades moderately cemented 18 11 29

18


23


14End at 21'

Remarks:


Page:

Groundwater encountered during drilling at depth of 3 feet and measured on 7/17/17 at depth of 3.9 feet. Figure:Slotted PVC pipe installed to depth of 21'



Water Depth: 3', 3.9' Job #: 100013400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 21' Date: 6/30/17

Surface Elev. (approx):

Remuda Elementary School Bore Hole Log B-6

0

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Type

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)

Dry

Den

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(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

SILTY CLAY (CL) with some fine sand; major roots (topsoil) to 4"; slightly moistbrown with mottling to moist 9

stiff 21 15 3217

SILTY SAND/GRAVELLY SAND (SM/SP) fine grained; with some silt; brown 4

saturated 22 5 12medium dense 7

grades gray 4SAND (SP) saturated 23 4 10 24.1 1 96 3fine grained; with trace gravel and silt; gray medium dense 6

424 11 23

12

825 9 16

7End at 15.5'

Remarks:


Page:

Groundwater encountered during drilling at depth of 4.5 feet and measured on 7/17/17 at depth of 4.25 feet. Figure:Slotted PVC pipe installed to depth of 14.5'



Water Depth: 4.5', 4.25' Job #: 100013400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 15.5' Date: 6/30/17



0

4

8

12

16

20

24

28

Dep

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GR

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Sam

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Type

Sam

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#

Tota

l

Moi

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e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

CLAY (CL) with some fine sand, trace organics; major slightly moist 6roots (topsoil) to 4"; brown with mottling to moist 26 12 27

stiff 15

SAND (SP) 3fine to medium grained; with trace silt; brown saturated 27 6 17

medium dense 11

grades gray 828 6 13

7

529 6 11

5

grades fine sand 730 8 15 25.8 0 98 2

7End at 15.5'

Remarks:


Page:

Groundwater encountered during drilling at depth of 3.5 feet and measured on 7/17/17 at depth of 4.4 feet. Figure:Slotted PVC pipe installed to depth of 10'



Water Depth: 3.5', 4.4' Job #: 100013400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 15.5' Date: 6/30/17



0

4

8

12

16

20

24

28

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GR

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ICLO

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Sam

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Type

Sam

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#

Tota

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Moi

stur

e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

SILTY SAND (SM) fine grained; brown

moist 5medium dense 31 6 13

7SAND (SP) very moistfine grained; gray to saturated 4

medium dense 32 4 117

End at 5'

Remarks:


Page:

Groundwater encountered during drilling at depth of 3.5 feet and measured on 7/17/17 at depth of 3.9 feet. Figure:Slotted PVC pipe installed to depth of 5'



Water Depth: 3.5', 3.9' Job #: 100013400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 5' Date: 6/30/17



0

4

8

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20

24

28

Dep

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GR

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ICLO

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Sam

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Type

Sam

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#

Tota

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Moi

stur

e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

CLAY (CL) with some fine sand; major roots (topsoil) to 4"; slightly moistbrown very stiff

very moist 733 9 18

SAND (SP) saturated 9fine grained; with some silt; cementation; brown

grades with trace silt; oxidation medium dense 634 8 18

10

835 11 25

14

1136 14 28

14

grades gray 1137 14 24

10

grades with fine sandy silt layers up to 2" thick dense 1338 20 40

20

SILT (ML) saturated 4with some fine sand; brown soft 39 1 4 34.9 25 22 3

3

Remarks:


Page:

Groundwater encountered during drilling at depth of 3 feet. Figure:Slotted PVC pipe installed to depth of 51.5'



Water Depth: 3' Job #: 100013400 North 3000 West, Farr West, Utah Boring Type: Hollow-Stem Auger Total Depth: 51.5' Date: 6/30/17



0

4

8

12

16

20

24

28

Dep

th (f

t)

GR

APH

ICLO

G

Sam

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Type

Sam

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#

Tota

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Moi

stur

e (%

)

Dry

Den

sity

(pcf

)

Gra

vel %

Sand

%

Fine

s %

LL PL PI

occasional layers of clayey silt with some fine sand medium stiff 3up to 3" thick 40 3 6 29 25 4

3

CLAY (CL) 0some fine sand; gray 41 2 6

4

soft 042 1 3

2

143 1 4 38.7 38 20 18

3

044 1 3

2End at 51.5'

Remarks:

Excavat

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