2-Geotechnical Report.pdf

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1497 West 40 South Lindon, Utah - 84042 Phone (801) 225-5711

840 West 1700 South #10 Salt Lake City, Utah - 84104 Phone (801) 787-9138

1596 W. 2650 S. #108 Ogden, Utah - 84401 Phone (801) 399-9516

Geotechnical Study Vineyard Skate Park

125 South Main Street Vineyard, Utah

Project No. 250082G

March 7, 2025

Prepared For:

Vineyard City Attention: Mr. Brian Vawdrey

125 South Main Street Vineyard, UT 84059

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TABLE OF CONTENTS

1.0 SUMMARY

2.0 INTRODUCTION

3.0 PROPOSED CONSTRUCTION

4.0 GENERAL SITE DESCRIPTION

4.1 Site Description

4.2 Geologic Setting

5.0 SUBSURFACE EXPLORATION

5.1 Soil Exploration

6.0 LABORATORY TESTING

7.0 SUBSURFACE CONDITIONS

7.1 Soil Types

7.2 Collapsible/Expansive Soils

7.3 Groundwater Conditions

8.0 SITE GRADING

8.1 General Site Grading

8.2 Temporary Excavations

8.3 Fill Material Composition

8.4 Fill Placement and Compaction

8.5 Stabilization Recommendations

9.0 SEISMIC AND GEOLOGIC CONSIDERATIONS

9.1 Seismic Design

9.2 Faulting

9.3 Liquefaction Potential

10.0 FOUNDATIONS

10.1 General

10.2 Strip/Spread Footings

10.3 Estimated Settlements

10.4 Lateral Load Resistance

11.0 FLOOR SLABS AND FLATWORK

12.0 DRAINAGE

12.1 Surface Drainagezzz

12.2 Subsurface Drainage

13.0 GENERAL CONDITIONS

ATTACHED FIGURES

No. 1 VICINITY MAP No. 2 AERIAL PHOTOGRAPH SHOWING LOCATION OF TEST PITS Nos. 3 – 6 TEST PIT LOGS No. 7 LEGEND Nos. 8 – 10 CONSOLIDATION-SWELL TEST

APPENDIX A

Chemtech-Ford Laboratories OSHPD-U.S. Seismic Design Maps

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Project No.: 250082G

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1.0 SUMMARY

This entire report presents the results of Earthtec Engineering’s completed geotechnical study for the Vineyard Skate Park in Vineyard, Utah. This summary provides a general synopsis of our recommendations and findings. Details of our findings, conclusions, and recommendations are provided within the body of this report.

• The native soils have a slight to moderate potential for collapse (settlement) and a slight to moderate potential for compression under increased moisture contents and anticipated load conditions. (see Section 6)

• Conventional strip and spread footings may be used to support the structures, with foundations placed entirely on firm, undisturbed, uniform native soils (i.e. completely on clay soils, or completely on sand soils, etc.), or entirely on a minimum of 18 inches of properly placed, compacted, and tested structural fill extending to undisturbed native soils for structural loads up to 1,000 pounds per linear foot and on a minimum of 18 inches of properly placed, compacted, and tested structural fill extending to undisturbed native soils for structural loads up to 5,000 pounds for column loads. If loads exceed these see Section 10 for further recommendations.

Based on the results of our field exploration, laboratory testing, and engineering analyses, it is our opinion that the subject site may be suitable for the proposed development, provided the recommendations presented in this report are followed and implemented during design and construction.

Failure to consult with Earthtec Engineering (Earthtec) regarding any changes made during design and/or construction of the project from those discussed herein relieves Earthtec from any liability arising from changed conditions at the site. We also strongly recommend that Earthtec observes the building excavations to verify the adequacy of our recommendations presented herein, and that Earthtec performs materials testing and special inspections for this project to provide continuity during construction.

2.0 INTRODUCTION

The project is located at approximately 125 South Main Street in Vineyard, Utah. The general location of the site is shown on Figure No. 1, Vicinity Map and Figure No. 2, Aerial Photograph Showing Location of Test Pits, at the end of this report. The purposes of this study are to evaluate the subsurface soil conditions at the site, assess the engineering characteristics of the subsurface soils, and provide geotechnical recommendations for general site grading and the design and construction of foundations, concrete floor slabs, and miscellaneous concrete flatwork.

The scope of work completed for this study included field reconnaissance, subsurface exploration, field and laboratory soil testing, geotechnical engineering analysis, and the preparation of this report. This report was prepared according to the signed agreement dated January 28, 2025.

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3.0 PROPOSED CONSTRUCTION

We understand that the proposed project, as described to us by Mr. Brain Vawdrey, consists of developing the approximately 0.7-acre existing parcel with the construction of a new skate park.

We anticipated that the proposed structures will consist of cast in place concrete structures and concrete slabs-on-grade. We have based our recommendations in this report that the anticipated foundation loads for the proposed structures will not exceed 1,000 pounds per linear foot for bearing walls, 5,000 pounds for column loads, and 100 pounds per square foot for floor slabs. If structural loads will be greater Earthtec should be notified so that we may review our recommendations and make modifications, if necessary.

In addition to the construction described above, we anticipate that utilities will be installed to service the proposed buildings, exterior concrete flatwork will be placed in the form of curb, gutter, and sidewalks.

4.0 GENERAL SITE DESCRIPTION

4.1 Site Description

At the time of our subsurface exploration the site was an undeveloped parcel vegetated with grass weeds and trees. The ground surface appears to be relatively flat; we anticipate less than 3 feet feet of cut and fill may be required for site grading. The lot was bounded on the north by Vineyard City Office, on the east and south by undeveloped land and residential properties, and on the west by South Main Street.

4.2 Geologic Setting

The subject property is located in the central portion of Utah Valley near the eastern shore of Utah Lake. Utah 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 bordered by the Wasatch Mountain Range on the east and the Lake Mountains on the west. Much of northwestern Utah, including Utah Valley, was previously covered by the Pleistocene age Lake Bonneville. Utah Lake, which currently covers much of the western portion of the valley, is a remnant of this ancient fresh water lake. The surficial geology of much of the eastern margin of the valley has been mapped by Constenius, 20111. The surficial geology at the location of the subject site and adjacent properties is mapped as “Spring and marsh deposits” (Map Unit Qsm) dated to Holocene to upper Pleistocene. These soil or deposits are generally described in the referenced mapping as “fine, organic-rich sediment associated with springs, ponds, seeps, and wetlands.” However, a geologic hazard study was not performed for the subject site during this study.

1 Constenius, K.N., Clark, D.L., King, J.K., Ehler, J.B., 2011, Interim Geologic Map of the Provo Quadrangle, Utah, Wasatch and Salt Lake Counties, Utah; U.S. Geological Survey, Open-File 586DM, Scale 1: 62,500

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5.0 SUBSURFACE EXPLORATION

5.1 Soil Exploration

Under the direction of a qualified member of our geotechnical staff, subsurface explorations were conducted at the site on February 13, 2025 by the excavation of four (4) test pits to depths of 4 to 11½ feet below the existing ground surface using a a track-mounted mini excavator. The approximate locations of the test pits are shown on Figure No. 2, Aerial Photograph Showing Location of Test Pits. Graphical representations and detailed descriptions of the soils encountered are shown on Figure Nos. 3 through 6, Test Pit Log at the end of this report. The stratification lines shown on the logs represent the approximate boundary between soil units; the actual transition may be gradual. Due to potential natural variations inherent in soil deposits, care should be taken in interpolating between and extrapolating beyond exploration points. A key to the symbols and terms on the logs is presented on Figure No. 7, Legend.

Disturbed bag samples and relatively undisturbed block samples were collected at various depths in each test pit. The soil samples collected were classified by visual examination in the field following the guidelines of the Unified Soil Classification System (USCS). The samples were transported to our Lindon, Utah laboratory where they will be retained for 30 days following the date of this report and then discarded, unless a written request for additional holding time is received prior to the 30-day limit.

6.0 LABORATORY TESTING

Representative soil samples collected during our field exploration were tested in the laboratory to assess pertinent engineering properties and to aid in refining field classifications, if needed. Tests performed included natural moisture contents, dry density tests, liquid and plastic limits determinations, mechanical (partial) gradation analyses, and one-dimensional consolidation tests. The laboratory test results are also included on the attached Test Pit Logs at the respective sample depths, and on Figure Nos. 8 through 10, Consolidation-Swell Test.

As part of the consolidation test procedure, water was added to the samples to assess moisture sensitivity when the samples were loaded to an equivalent pressure of approximately 1,000 psf.

The native soils have a slight to moderate potential for collapse (settlement) and a slight to moderate potential for compression under increased moisture contents and anticipated load conditions.

A water-soluble sulfate test was performed on a representative sample obtained during our field exploration which indicated a value of 461 parts per million. Based on this result, the risk of sulfate attack to concrete appears to be “moderate” according to American Concrete Institute standards.

Therefore, we recommend that Type II Portland cement be used for concrete in contact with on-site soils. The results can be found in Appendix A.

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7.0 SUBSURFACE CONDITIONS

7.1 Soil Types

On the surface of the site, we encountered fill and topsoil which is estimated to extend about 3 to 4 feet in depth at the test pit locations. Below the fill and topsoil we encountered layers of clay, silt, sand, and gravel extending to depths of 4 to 11½ feet below the existing ground surface.

Graphical representations and detailed descriptions of the soils encountered are shown on Figure Nos. 3 through 6, Test Pit Log at the end of this report. Based on our experience and observations during field exploration, the clay and silt soils visually ranged from medium stiff to stiff in consistency and the sand and gravel soils visually had a relative density varying from medium dense to very dense.

It should be considered that a limited number of test pits were used during the course of our subsurface exploration. Topsoil and fill material composition and contacts are difficult to determine from test pit sampling. Variation in topsoil and fill depths may occur at the site.

7.2 Collapsible/Expansive Soils

Collapsible soils are typically characterized by a pinhole structure and relatively low unit weights.

Foundations, floor slabs, and roadways supported on these soils may be susceptible to large settlements and structural distress when wetted. Significantly collapsible soils were not encountered in our explorations.

7.3 Groundwater Conditions

Groundwater was not encountered within the excavations at the depths explored. We did not observe oxidation or other indicators in the soils which would indicate signs of past water or seepage levels shallower than the groundwater. No artesian conditions were encountered during our explorations. Note that groundwater levels will fluctuate in response to the season, precipitation, snow melt, irrigation, and other on and off-site influences. Quantifying these fluctuations would require long term monitoring, which is beyond the scope of this study. The contractor should be prepared to dewater excavations as needed.

8.0 SITE GRADING

8.1 General Site Grading

All surface vegetation and unsuitable soils (such as topsoil, organic soils, undocumented fill, soft, loose, or disturbed native soils, collapsible, and any other inapt materials) should be removed from below foundations, floor slabs, and exterior concrete flatwork. We encountered fill and topsoil on the surface of the site. The fill encountered on the site is considered undocumented (untested).

The fill and topsoil (including soil with roots larger than about ¼ inch in diameter) should be completely removed, even if found to extend deeper, along with any other unsuitable soils that may be encountered. Over-excavations below footings and slabs also may be needed, as

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Fill placed over large areas, even if only a few feet in depth, can cause consolidation in the underlying native soils resulting in settlement of the fill. Because the site is relatively flat, we anticipate that less than 3 feet of grading fill will be placed. If more than 3 feet of grading fill will be placed above the existing surface (to raise site grades), Earthtec should be notified so that we may provide additional recommendations, if required. Such recommendations will likely include placing the fill several weeks (or possibly more) prior to construction to allow settlement to occur.

8.2 Temporary Excavations

Temporary excavations that are less than 4 feet in depth and above groundwater should have side slopes no steeper than ½H:1V (Horizontal:Vertical). Temporary excavations where water is encountered in the upper 4 feet or that extend deeper than 4 feet below site grades should be sloped or braced in accordance with OSHA2 requirements for Type B soils. Choose an item.

8.3 Fill Material Composition

The existing fill soils are not suitable for use as placed and compacted engineered fill. Excavated soils, including clay and silt, may be stockpiled for use as fill in landscape areas.

Structural fill is defined as imported fill material that will ultimately be subjected to any kind of structural loading, such as those imposed by footings, floor slabs, pavements, etc. Gradation requirements stated below shall be verified in intervals not exceeding 1,000 tons. We recommend that imported structural fill consist of sandy/gravelly soils meeting the following requirements in the table below:

Table 1: Imported Structural Fill Recommendations Sieve Size/Other Percent Passing (by weight)

4 inches 100 3/4 inches 70 – 100

No. 4 40 – 80 No. 40 15 – 50

No. 200 0 – 20 Liquid Limit 35 maximum

Plasticity Index 15 maximum

Engineered fill is defined as reworked native, granular (sands or gravels) material that will ultimately be subjected to any kind of structural loading, such as those imposed by footings, floor slabs, pavements, etc. Native clay and silt soils are not suitable for use as engineered fill. We recommend that a professional engineer or geologist verify that the engineered fill to be used on this project meets the requirements. Engineered fill should be clear of all organics, have a maximum particle size of 4 inches, less than 70 percent retained on the ¾-seive, a maximum

2 OSHA Health and Safety Standards, Final Rule, CFR 29, part 1926.

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Liquid Limit of 35, and a maximum Plasticity Index of 15.

In some situations, particles larger than 4 inches and/or more than 30 percent coarse gravel may be acceptable but would likely make compaction more difficult and/or significantly reduce the possibility of successful compaction testing. Consequently, stricter quality control measures than normally used may be required, such as using thinner lifts and increased or full-time observation of fill placement.

We recommend that utility trenches below any structural load be backfilled using structural fill or engineered fill. Local governments or utility companies required specification for backfill should be followed unless our recommendations stricter.

If native soil is used as fill material, the contractor should be aware that native clay and silt soils (as observed in the explorations) may be time consuming to compact due to potential difficulties in controlling the moisture content needed to obtain optimum compaction and changes proctor values.

If required (i.e. fill in submerged areas), we recommend that free draining granular material (clean sand and/or gravel) meet the following requirements in the table below:

Table 2: Free-Draining Fill Recommendations Sieve Size/Other Percent Passing (by weight)

3 inches 100 No. 10 0 – 25 No. 40 0 – 15

No. 200 0 – 5 Plasticity Index Non-plastic

Three-inch minus washed rock (sometimes called river rock or drain rock) and pea gravel materials usually meet these requirements and may be used as free draining fill. If free draining fill will be placed adjacent to soil containing a significant amount of sand or silt/clay, precautions should be taken to prevent the migration of fine soil into the free draining fill. Such precautions should include either placing a filter fabric between the free draining fill and the adjacent soil material, or using a well-graded, clean filtering material approved by the geotechnical engineer.

8.4 Fill Placement and Compaction

The thickness of each lift should be appropriate for the compaction equipment that is used. We recommend a maximum lift thickness prior to compaction of 4 inches for hand operated equipment, 6 inches for most “trench compactors” and 8 inches for larger rollers, unless it can be demonstrated by in-place density tests that the required compaction can be obtained throughout a thicker lift. The full thickness of each lift of structural fill placed should be compacted to at least the following percentages of the maximum dry density, as determined by ASTM D-1557:

• In landscape and other areas not below structurally loaded areas: 90%

• Less than 5 feet of fill below structurally loaded areas: 95%

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• 5 feet or greater of fill below structurally loaded areas: 98%

Generally, placing and compacting fill at moisture contents within ±2 percent of the optimum moisture content, as determined by ASTM D-1557, will facilitate compaction. Typically, the further the moisture content deviates from optimum the more difficult it will be to achieve the required compaction.

Fill should be tested frequently during placement, and we recommend early testing to demonstrate that placement and compaction methods are achieving the required compaction. For mass grading or building pads a minimum of one test per 5,000 square feet per lift, with a minimum of 2 tests per lift. For trenches one test per 100 linear feet per lift is required. The contractor is responsible to ensure that fill materials and compaction efforts are consistent so that tested areas are representative of the entire fill.

8.5 Stabilization Recommendations

Near surface soils may rut and pump during grading and construction. The likelihood of rutting and/or pumping, and the depth of disturbance, is proportional to the moisture content in the soil, the load applied to the ground surface, and the frequency of the load. Consequently, rutting and pumping can be minimized by avoiding concentrated traffic, minimizing the load applied to the ground surface by using lighter equipment, partially loaded equipment, tracked equipment, by working in dry times of the year, and/or by providing a working surface for equipment.

During grading the soil in any obvious soft spots should be removed and replaced with granular material. If rutting or pumping occurs traffic should be stopped in the area of concern. The soil in rutted areas should be removed and replaced with granular material. In areas where pumping occurs the soil should either be allowed to sit until pore pressures dissipate (several hours to several days) and the soil firms up or be removed and replaced with granular material. Typically, we recommend removal to a minimum depth of 24 inches.

For granular material, we recommend using angular well-graded gravel, such as pit run, or crushed rock with a maximum particle size of four inches. We suggest that the initial lift be approximately 12 inches thick and be compacted with a static roller-type compactor. A finer granular material such as sand, gravelly sand, sandy gravel or road base may also be used.

Materials which are more angular and coarse may require thinner lifts in order to achieve compaction. We recommend that the fines content (percent passing the No. 200 sieve) be less than 15%, the liquid limit be less than 35, and the plasticity index be less than 15.

Using a geosynthetic fabric, such as Mirafi 600X or equivalent, may also reduce the amount of material required and avoid mixing of the granular material and the subgrade. If a fabric is used, following removal of disturbed soils and water, the fabric should be placed over the bottom and up the sides of the excavation a minimum of 24 inches. The fabric should be placed in accordance with the manufacturer’s recommendations, including proper overlaps. The granular material should then be placed over the fabric in compacted lifts. Again, we suggest that the initial lift be approximately 12 inches thick and be compacted with a static roller-type compactor.

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9.0 SEISMIC AND GEOLOGIC CONSIDERATIONS

9.1 Seismic Design

The State of Utah has adopted the 2021 International Building Code (IBC) for seismic design and the structure should be designed in accordance with Chapter 16 of the IBC. Considering our experience in the vicinity of the site and based on the results of our field exploration, we recommend using Site Class D (Default).

The site is located at approximately 40.294 degrees latitude and -111.752 degrees longitude.

Using Site Class D (Default), the design spectral response acceleration parameters are given below.

Table 3: Design Accelerations SS Fa SMS SDS S1

1.281 g 1.2 1.538 g 1.025 g 0.46 g

9.2 Faulting

The subject property is located within the Intermountain Seismic Belt where the potential for active faulting and related earthquakes is present. Based upon published geologic maps3, no active faults traverse through or immediately adjacent to the site and the site is not located within local fault study zones. The nearest mapped fault trace is part of a group of faults beneath Utah Lake located about two miles west of the site.

9.3 Liquefaction Potential

According to current liquefaction maps4 for Utah County, the site is located within an area designated as “High” in liquefaction potential. Liquefaction can occur when saturated subsurface soils below groundwater lose their inter-granular strength due to an increase in soil pore water pressures during a dynamic event such as an earthquake. Loose, saturated sands are most susceptible to liquefaction, but some loose, saturated gravels and relatively sensitive silt to low-plasticity silty clay soils can also liquefy during a seismic event. Subsurface soils encountered were composed of unsaturated clay, silt, sand and gravel soils.

The soils encountered at this project do not appear liquefiable, but the liquefaction susceptibility of underlying soils (deeper than our explorations) is not known and would require deeper explorations to quantify.

3 U.S. Geological Survey, Quaternary Fault and Fold Database of the United States, November 3, 2010.

4 Christenson, G.E., Shaw, L.M., 2008, Liquefaction Special Study Areas, Wasatch and Nearby Areas, Utah; Utah Geological Survey, Map to Circular 106, Scale 1:250,000

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10.0 FOUNDATIONS

10.1 General

The foundation recommendations presented in this report are based on the soil conditions encountered during our field exploration, the results of laboratory testing of samples of the native soils, the site grading recommendations presented in this report, and the foundation loading conditions presented in Section 3.0, Proposed Construction, of this report. If loading conditions and assumptions related to foundations are significantly different, Earthtec should be notified so that we can re-evaluate our design parameters and estimates (higher loads may cause more settlement), and to provide additional recommendations if necessary.

Conventional strip and spread footings may be used to support the proposed structures after appropriate removals as outlined in Section 8.1. Foundations should not be installed on topsoil, undocumented fill, debris, combination soils, organic soils, frozen soil, or in ponded water. If foundation soils become disturbed during construction, they should be removed or compacted.

10.2 Strip/Spread Footings

We recommend that conventional strip and spread foundations be constructed entirely on firm, undisturbed, uniform native soils (i.e. completely on clay soils, or completely on sand soils, etc.), or entirely on a minimum of 18 inches of properly placed, compacted, and tested structural fill extending to undisturbed native soils for structural loads up to 1,000 pounds per linear foot and on a minimum of 18 inches of properly placed, compacted, and tested structural fill extending to undisturbed native soils for structural loads up to 5,000 pounds for column loads. If loads exceed 1,000 pounds per linear foot for bearing walls, 5,000 pounds for column loads, please contact Earthtec for further recommendations. For foundation design we recommend the following:

• Footings founded on undisturbed native soils may be designed using a maximum allowable bearing capacity of 1,500 pounds per square foot. Footings founded on a minimum of 18 inches of structural fill extending to undisturbed native soil may be designed using a maximum allowable bearing capacity of 2,000 pounds per square foot. The values for vertical foundation pressure can be increased by one-third for wind and seismic conditions per Section 1806 when used with the Alternative Basic Load Combinations found in Section 1605.2 of the 2021 International Building Code.

• Continuous and spot footings should be uniformly loaded and should have a minimum width of 20 and 30 inches, respectively.

• Exterior footings should be placed below frost depth which is determined by local building codes. In general, 30 inches of cover is adequate for most sites; however local code should be verified by the end design professional. Interior footings, not subject to frost (heated structures), should extend at least 18 inches below the lowest adjacent grade.

• Foundation walls and footings should be properly reinforced to resist all vertical and lateral loads and differential settlement.

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• The bottom of footing excavations should be compacted with at least 4 passes of an approved non-vibratory roller prior to erection of forms or placement of structural fill to densify soils that may have been loosened during excavation and to identify soft spots. If soft areas are encountered, they should be stabilized as recommended in Section 8.5.

• Footing excavations should be observed by the geotechnical engineer prior to beginning fill placement or footing construction if fill is not required to evaluate whether suitable bearing soils have been exposed and whether excavation bottoms are free of loose or disturbed soils.

• Structural fill used below foundations should extend laterally a minimum of 6 inches for every 12 vertical inches of structural fill placed. For example, if 18 inches of structural fill is required to bring the excavation to footing grade, the structural fill should extend laterally a minimum of 9 inches beyond the edge of the footings on both sides.

10.3 Estimated Settlements

If the proposed foundations are properly designed and constructed using the parameters provided above, we estimate that total settlements should not exceed one inch and differential settlements should be one-half of the total settlement over a 25-foot length of continuous foundation, for non-earthquake conditions. Additional settlement could occur during a seismic event due to ground shaking, if more than 3 feet of grading fill is placed above the existing ground surface, if loading conditions are greater than anticipated in Section 2, if any of the recommendations in Section 12 are not followed, and/or if foundation soils are allowed to become wetted.

10.4 Lateral Load Resistance

Lateral loads are typically resisted by friction between the underlying soil and footing bottoms.

Resistance to sliding may incorporate the friction acting along the base of foundations, which may be computed using a coefficient of friction of soils against concrete of 0.20 for native clay and silts, 0.25 for native sands, and 0.35 for native gravels, clean gravel, or structural fill meeting the recommendations presented herein. The values for lateral resistance can be increased by one-third for wind and seismic conditions per Section 1806 when used with the Alternative Basic Load Combinations found in Section 1605.3.2 of the 2021 International Building Code.

11.0 FLOOR SLABS AND FLATWORK

Concrete floor slabs and exterior flatwork may be supported on a minimum of 12 inches properly placed, compacted, and tested engineered fill or imported structural fill extending to undisturbed native soils after appropriate removals and grading as outlined in Sections 7.2 and 8.1 are completed. We recommend placing a minimum of 4 inches of free-draining fill material (see Section 8.3) beneath floor slabs to facilitate construction, act as a capillary break, and aid in distributing floor loads. For exterior flatwork, we recommend placing a minimum of 4 inches of road-base material. Prior to placing the free-draining fill or road-base materials, the native sub-grade should be proof-rolled to identify soft spots, which should be stabilized as discussed above

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For slab design, we recommend using a modulus of sub-grade reaction of 120 pounds per cubic inch. The thickness of slabs supported directly on the ground shall not be less than 3½ inches. A 6-mil polyethylene vapor retarder with joints lapped not less than 6 inches shall be placed between the ground surface and the concrete, as per Section 1907.1 of the 2021 International Building Code.

To help control normal shrinkage and stress cracking, we recommend that floor slabs have adequate reinforcement for the anticipated floor loads with the reinforcement continuous through interior floor joints, frequent crack control joints, and non-rigid attachment of the slabs to foundation and bearing walls. Special precautions should be taken during placement and curing of all concrete slabs and flatwork. Excessive slump (high water-cement ratios) of the concrete and/or improper finishing and curing procedures used during hot or cold weather conditions may lead to excessive shrinkage, cracking, spalling, or curling of slabs. We recommend all concrete placement and curing operations be performed in accordance with American Concrete Institute (ACI) codes and practices.

12.0 DRAINAGE

12.1 Surface Drainage

As part of good construction practice, precautions should be taken during and after construction to reduce the potential for water to collect near foundation walls. Accordingly, we recommend the following:

• The contractor should take precautions to prevent significant wetting of the soil at the base of the excavation. Such precautions may include: grading to prevent runoff from entering the excavation, excavating during normally dry times of the year, covering the base of the excavation if significant rain or snow is forecast, backfill at the earliest possible date, frame floors and/or the roof at the earliest possible date, other precautions that might become evident during construction.

• Adequate compaction of foundation wall backfill must be provided i.e. a minimum of 90% of ASTM D-1557. Water consolidation methods should not be used.

• The ground surface should be graded to drain away from the building in all directions. We recommend a minimum fall of 8 inches in the first 10 feet.

• Roof runoff should be collected in rain gutters with down spouts designed to discharge well outside of the backfill limits, or at least 10 feet from foundations, whichever is greater.

• Sprinkler nozzles should be aimed away, and all sprinkler components kept at least 5 feet, from foundation walls. A drip irrigation system may be utilized in landscaping areas within 10 feet of foundation walls to minimize water intrusion of foundation backfill. Also, sprinklers

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• Any additional precautions which may become evident during construction.

12.2 Subsurface Drainage

Walls or portions thereof that retain earth and enclose interior spaces and floors below grade shall conform to Section 1805 of the 2021 International Building Code for damp proofing and water proofing.

13.0 GENERAL CONDITIONS

The exploratory data presented in this report was collected to provide geotechnical design recommendations for this project. The explorations may not be indicative of subsurface conditions outside the study area or between points explored and thus have a limited value in depicting subsurface conditions for contractor bidding. Variations from the conditions portrayed in the explorations may occur and which may be sufficient to require modifications in the design. If during construction, conditions are different than presented in this report, Earthtec should be advised immediately so that the appropriate modifications can be made.

The findings and recommendations presented in this geotechnical report were prepared in accordance with generally accepted geotechnical engineering principles and practice in this area of Utah at this time. No warranty or representation is intended in our proposals, contracts, letters, or reports. Failure to consult with Earthtec regarding any changes made during design and/or construction of the project from those discussed herein relieves Earthtec from any liability arising from changed conditions at the site.

This geotechnical report is based on relatively limited subsurface explorations and laboratory testing. Subsurface conditions may differ in some locations of the site from those described herein, which may require additional analyses and possibly modified recommendations. Thus, we strongly recommend consulting with Earthtec regarding any changes made during design and construction of the project from those discussed herein. Failure to consult with Earthtec regarding any such changes relieves Earthtec from any liability arising from changed conditions at the site.

To maintain continuity, Earthtec should also perform materials testing and special inspections for this project. The recommendations presented herein are based on the assumption that an adequate program of tests and observations will be followed during construction to verify compliance with our recommendations. We also assume that we will review the project plans and specifications to verify that our conclusions and recommendations are incorporated and remain appropriate (based on the actual design). Earthtec should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Earthtec also should be retained to provide observation and testing services during grading, excavation, foundation

Geotechnical Study Page 13

125 South Main Street

Professional Engineering Services ~ Geotechnical Engineering ~ Geologic Studies ~ Code Inspections ~ Special Inspection / Testing ~ Non-Destructive Examination ~ Failure Analysis construction, and other earth-related construction phases of the project.

This report is valid until the legislative adoption of an updated IBC/IRC code. At that time, an update to this report will be required to validate the results. This report is for the exclusive use of the Client named on the title page of this report and may not be relied upon by any party other than the Client. Some or all of the information in this report may come into the possession of third parties. No such third parties shall have rights of recourse or action against EE, its officers, employees, vendors, successors, or assigns in the absence of a written agreement from EE granting such reliance to third parties. All general conditions within the signed proposal between Earthtec Engineering and the Client remain applicable to this report.

We appreciate the opportunity of providing our services on this project. If we can answer questions or be of further service, please contact Earthtec at your convenience.

Respectfully;

EARTHTEC ENGINEERING

03/07/2025

Jeremy A. Balleck, E.I.T. Timothy A. Mitchell, P.E.

Staff Engineer Vice President

PROJECT NO.: 250082G FIGURE NO.: 1

VICINITY MAP

VINEYARD SKATE PARK

125 SOUTH MAIN STREET

VINEYARD, UTAH

N

Not to Scale

Approximate Site Location

PROJECT NO.: 250082G FIGURE NO.: 2

AERIAL PHOTOGRAPH SHOWING

LOCATION OF TEST PITS

VINEYARD SKATE PARK

125 SOUTH MAIN STREET

VINEYARD, UTAH

N

Not to Scale

TP-1

TP-2

Approximate Test Pit Locations

TP-3

TP-4

D ep th

Sa m pl e

Ty pe

Gr ap hi c

Lo g

No groundwater encountered

Lithologic Description

FILL

lean clay, moist, brown, debris

SILT

medium stiff (estimated), slightly moist, light brown, porous, light to heavy cementation

_Silty _GRAVEL _with sand medium dense (estimated), moist, light brown, porous, cemented

_Lean CLAY medium stiff (estimated), moist, brown

Test Pit Terminated at 11½ feet

US

CS

So il

Cl as s

GM

M oi st ur e

D ry

D en sit y

Gr av el

Sa nd

Fi ne s

Li qu id Li m it

Pl as tic In de x

NP

O th er Te st s

C

R

SL

og

Te st

P it

Lo g

(L et te r)

/ e ar th te c-en gi ne er in g / a dm in

M ar ch

6, :5

AM

TEST PIT LOG:TP-1

COORD.:

LOGGED BY: JAB

DATE: 2025-02-13

Mini Excavator OPERATOR: D. Judd

EQUIPMENT:

LOCATION: See Figure No. 2

ELEVATION:

CLIENT:

PROJECT TITLE:

Vineyard City

FIGURE NO.: 3PROJECT NO.: 250082G

th

Sa m pl e

Ty pe

Gr ap hi c

Lo g

No groundwater encountered

Lithologic Description

FILL

lean clay, moist, dark brown, debris

TOPSOIL

lean clay, moist, dark brown, roots

_Sandy SILT medium stiff (estimated), slightly moist, light brown, light to heavy cementation

_Lean CLAY medium stiff (estimated), moist, brown to gray, mottled, slightly porous

... blocky

Test Pit Terminated at 11 feet

US

CS

So il

Cl as s

ML

M oi st ur e

D ry

D en sit y

Gr av el

Sa nd

Fi ne s

Li qu id Li m it

Pl as tic In de x

O th er Te st s

C

R

SL

og

Te st

P it

Lo g

(L et te r)

/ e ar th te c-en gi ne er in g / a dm in

M ar ch

6, :5

AM

TEST PIT LOG:TP-2

COORD.:

LOGGED BY: JAB

DATE: 2025-02-13

Mini Excavator OPERATOR: D. Judd

EQUIPMENT:

LOCATION: See Figure No. 2

ELEVATION:

CLIENT:

PROJECT TITLE:

Vineyard City

FIGURE NO.: 4PROJECT NO.: 250082G

th

Sa m pl e

Ty pe

Gr ap hi c

Lo g

No groundwater encountered

Lithologic Description

FILL

lean clay, slightly moist, light brown, debris

TOPSOIL

lean clay, moist, brown

_Silty SAND dense to very dense (estimated), dry, brown, heavily cemented

Test Pit Terminated at 4 feet due to equipment refusal

US

CS

So il

Cl as s

M oi st ur e

D ry

D en sit y

Gr av el

Sa nd

Fi ne s

Li qu id Li m it

Pl as tic In de x

O th er Te st s

R

SL

og

Te st

P it

Lo g

(L et te r)

/ e ar th te c-en gi ne er in g / a dm in

M ar ch

6, :5

AM

TEST PIT LOG:TP-3

COORD.:

LOGGED BY: JAB

DATE: 2025-02-13

Mini Excavator OPERATOR: D. Judd

EQUIPMENT:

LOCATION: See Figure No. 2

ELEVATION:

CLIENT:

PROJECT TITLE:

Vineyard City

FIGURE NO.: 5PROJECT NO.: 250082G

th

Sa m pl e

Ty pe

Gr ap hi c

Lo g

No groundwater encountered

Lithologic Description

FILL

lean clay, moist, brown, sod

_Silty SAND dense (estimated), slightly moist, gray, cemented

Sandy Lean_CLAY medium stiff (estimated), moist, dark brown to light brown, porous, rootholes

_Silty SAND medium dense (estimated), moist, light brown

Test Pit Terminated at 10 feet

US

CS

So il

Cl as s

CL

M oi st ur e

D ry

D en sit y

Gr av el

Sa nd

Fi ne s

Li qu id Li m it

Pl as tic In de x

O th er Te st s

SS

C

R

SL

og

Te st

P it

Lo g

(L et te r)

/ e ar th te c-en gi ne er in g / a dm in

M ar ch

6, :5

AM

TEST PIT LOG:TP-4

COORD.:

LOGGED BY: JAB

DATE: 2025-02-13

Mini Excavator OPERATOR: D. Judd

EQUIPMENT:

LOCATION: See Figure No. 2

ELEVATION:

CLIENT:

PROJECT TITLE:

Vineyard City

FIGURE NO.: 6PROJECT NO.: 250082G

UNIFIED SOIL CLASSIFICATION SYSTEM

COARSE

GRAINED

SOILS

(More than 50% retaining on No.

200 Sieve)

FINE

GRAINED

SOILS

(More than 50% passing No. 200

Sieve)

GRAVELS

(More than 50% of coarse fraction retained on No. 4

Sieve)

GRAVELS

WITH FINES

(More than 12% fines)

CLEAN GRAVELS

(Less than 5% fines)

CLEAN SANDS

(Less than 5% fines)

SANDS

WITH FINES

(More than 12% fines)

SILTS AND CLAYS

(Liquid Limit less than 50)

SILTS AND CLAYS

(Liquid Limit Greater than 50)

HIGHLY ORGANIC SOILS

Well Graded Gravel, May Contain Sand, Very Few Fines

Poorly Graded Gravel, May Contain Sand, Very Few Fines

Silty Gravel, May Contain Sand

Clayey Gravel, May Contain Sand

Well Graded Sand, May Contain Gravel, Very Few Fines

Poorly Graded Sand, May Contain Gravel, Very Few Fines

Silty Sand, May Contain Gravel

Clayey Sand, May Contain Gravel

Lean Clay, Inorganic, May Contain Gravel and/or Sand

Silt, Inorganic, May Contain Gravel and/or Sand

Organic Silt or Clay, May Contain Gravel and/or Sand

Fat Clay, Inorganic, May Contain Gravel and/or Sand

Elastic Silt, Inorganic, May Contain Gravel and/or Sand

Organic Clay or Silt, May Contain Gravel and/or Sand

Peat, Primarily Organic Matter

FIGURE NO.:

LEGEND

SAMPLER DESCRIPTIONS

SPLIT SPOON SAMPLER

(1 3/8 inch inside diameter)

WATER SYMBOLS

Water level encountered during field exploration

Water level encountered at completion of field exploration

MAJOR SOIL DIVISIONS

USCS

SYMBOL TYPICAL SOIL DESCRIPTIONS

NOTES:

MODIFIED CALIFORNIA SAMPLER

(2 inch outside diameter)

SHELBY TUBE

(3 inch outside diameter)

ROCK CORE RUN

BLOCK SAMPLE

BAG/BULK SAMPLE

1. The logs are subject to the limitations, conclusions, and recommendations in this report.

2. Results of tests conducted on samples recovered are reported on the logs and any applicable graphs.

3. Strata lines on the logs represent approximate boundaries only. Actual transitions may be gradual.

4. In general, USCS symbols shown on the logs are based on visual methods only: actual designations

(based on laboratory tests) may vary.

GW

GP

GM

GC

SW

SP

SM

SC

CL

ML

OL

CH

MH

OH

PT

SANDS

(50% or more of coarse fraction passes No. 4

Sieve)

PROJECT NO.: 250082G 7

Project: Vineyard Skate Park Location: TP-1 Sample Depth, ft: 6 Description: Block Soil Type: Silty GRAVEL with sand (GM) Natural Moisture, %: 14 Dry Density, pcf: 101 Liquid Limit: 29 Plasticity Index: NP Water Added at: 1 ksf Percent Collapse: 0.3

PROJECT NO.: 250082G FIGURE NO.: 8

CONSOLIDATION - SWELL TEST

-18

-16

-14

-12

-10

-8

-6

-4

-2

0.1 1 10

C on so lid at io n

Pressure (ksf)

Location: TP-2 Sample Depth, ft: 3 Description: Block Soil Type: Sandy SILT (ML) Natural Moisture, %: 8 Dry Density, pcf: 104 Liquid Limit: --- Plasticity Index: --- Water Added at: 1 ksf Percent Collapse: 1.2

PROJECT NO.: 250082G FIGURE NO.: 9

CONSOLIDATION - SWELL TEST

-18

-16

-14

-12

-10

-8

-6

-4

-2

0.1 1 10

C on so lid at io

Location: TP-4 Sample Depth, ft: 7½ Description: Block Soil Type: Sandy Lean CLAY (CL) Natural Moisture, %: 32 Dry Density, pcf: 92 Liquid Limit: 29 Plasticity Index: 8 Water Added at: 1 ksf Percent Collapse: 0.2

PROJECT NO.: 250082G FIGURE NO.: 10

CONSOLIDATION - SWELL TEST

-18

-16

-14

-12

-10

-8

-6

-4

-2

0.1 1 10

C on so lid at io

APPENDIX A

xx

Serving the Intermountain West Since 1953

Certificate of Analysis

9632 South 500 West

Sandy, UT 84070

O:(801) 262-7299 F: (866) 792-0093 www.ChemtechFord.com

BGT Partners (dba Earthtec Engineering)

Jeremy Balleck

1497 West 40 South

Lindon, UT 84042

PO#:

Receipt:

Date Reported:

Project Name:

250082G

2/14/25 13:45 @ 21.6 °C

2/20/2025

Vineyard Skate Park

Sample ID: 250082 TP4 @ 4

Lab ID: 25B1154-01Matrix: Solid

Flag(s)Units

Analysis

Date/Time

Date Sampled: 2/13/25 11:00

Preparation

Date/Time

Sampled By: Client

Minimum

Reporting

Limit MethodResult

Inorganic mg/kg dry 2/18/252/18/2513 EPA 300.0461Sulfate, Soluble (IC)

% 2/18/252/18/250.1 CTF800076.6Total Solids

Project Name: Vineyard Skate Park CtF WO#: 25B1154 www.ChemtechFord.com Page 1 of 3Page 1 of 3 xx

Serving the Intermountain West Since 1953

Certificate of Analysis

9632 South 500 West

Sandy, UT 84070

O:(801) 262-7299 F: (866) 792-0093 www.ChemtechFord.com

BGT Partners (dba Earthtec Engineering)

Jeremy Balleck

1497 West 40 South

Lindon, UT 84042

PO#:

Receipt:

Date Reported:

Project Name:

250082G

2/14/25 13:45 @ 21.6 °C

2/20/2025

Vineyard Skate Park

Report Footnotes

Abbreviations

ND = Not detected at the corresponding Minimum Reporting Limit (MRL).

1 mg/L = one milligram per liter or 1 mg/kg = one milligram per kilogram = 1 part per million.

1 ug/L = one microgram per liter or 1 ug/kg = one microgram per kilogram = 1 part per billion.

1 ng/L = one nanogram per liter or 1 ng/kg = one nanogram per kilogram = 1 part per trillion.

On calculated parameters, there may be a slight difference between summing the rounded values shown on the report vs the unrounded values used in the calculation.

Chemtech-Ford, Inc

Joyce Applegate, Project Manager

Analyses presented in this report were performed in accordance with the

National Environmental Laboratory Accreditation Conference , unless otherwise noted.

Project Name: Vineyard Skate Park CtF WO#: 25B1154 www.ChemtechFord.com Page 2 of 3Page 2 of 3

USGS web services were down for some period of time and as a result this tool wasn't operational, resulting in timeout error.

USGS web services are now operational so this tool should work as expected.

Latitude, Longitude: 40.29420279151112, -111.75240610017276

Date 3/6/2025, 11:19:27 AM

Design Code Reference Document ASCE7-16

Risk Category II

Site Class D - Default (See Section 11.4.3)

Type Value Description SS 1.281 MCER ground motion. (for 0.2 second period)

S1 0.46 MCER ground motion. (for 1.0s period)

SMS 1.538 Site-modified spectral acceleration value

SM1 null -See Section 11.4.8 Site-modified spectral acceleration value

SDS 1.025 Numeric seismic design value at 0.2 second SA

SD1 null -See Section 11.4.8 Numeric seismic design value at 1.0 second SA

Type Value Description SDC null -See Section 11.4.8 Seismic design category

Fa 1.2 Site amplification factor at 0.2 second

Fv null -See Section 11.4.8 Site amplification factor at 1.0 second

PGA 0.576 MCEG peak ground acceleration

FPGA 1.2 Site amplification factor at PGA

PGAM 0.691 Site modified peak ground acceleration

TL 8 Long-period transition period in seconds

SsRT 1.281 Probabilistic risk-targeted ground motion. (0.2 second)

SsUH 1.473 Factored uniform-hazard (2% probability of exceedance in 50 years) spectral acceleration

SsD 3.087 Factored deterministic acceleration value. (0.2 second)

S1RT 0.46 Probabilistic risk-targeted ground motion. (1.0 second)

S1UH 0.519 Factored uniform-hazard (2% probability of exceedance in 50 years) spectral acceleration.

S1D 1.2 Factored deterministic acceleration value. (1.0 second)

PGAd 1.229 Factored deterministic acceleration value. (Peak Ground Acceleration)

PGAUH 0.576 Uniform-hazard (2% probability of exceedance in 50 years) Peak Ground Acceleration

CRS 0.87 Mapped value of the risk coefficient at short periods

3/6/25, 11:19 AM U.S. Seismic Design Maps https://www.seismicmaps.org 1/3

Type Value Description CR1 0.886 Mapped value of the…