77-6 GeoTech Report KRAZAN 052-24055.pdf

GEOTECHNICAL ENGINEERING INVESTIGATION

CAMERON CREEK CHECK STRUCTURES

TULARE COUNTY, CALIFORNIA

PROJECT NO. 052-24055

SEPTEMBER 9, 2024

Prepared for:

MR. MATT KLINCHUCH

PROVOST & PRITCHARD CONSULTING GROUP

130 NORTH GARDEN STREET

VISALIA, CALIFORNIA 93291

Prepared by:

CTL-KRAZAN

GEOTECHNICAL ENGINEERING DIVISION

710 SOUTH KAWEAH AVENUE

EXETER, CALIFORNIA 93221

(559) 592-3555

G E O T E C H N I C A L E N G I N E E R I N G E N V I R O N M E N T A L E N G I N E E R I N G C O N S T R U C T I O N T E S T I N G & I N S P E C T I O N

Offices Serving the Western United States

710 South Kaweah Avenue Exeter CA 93221 (559) 592-3555 Fax: (559) 592-3553 05224055 Report (Cameron Creek)

September 9, 2024 CTL-Krazan Project No. 052-24055

Mr. Matt Klinchuch Provost & Pritchard Consulting Group 130 North Garden Street Visalia, California 93291

RE: Geotechnical Engineering Investigation

Cameron Creek Check Structures Tulare County, California

Dear Mr. Klinchuch:

In accordance with your request, we have completed a Geotechnical Engineering Investigation for the above-referenced site. The results of our investigation are presented in the attached report.

If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (559) 592-3555.

Respectfully submitted, CTL-Krazan

Steven W. Short Engineering Manager RCE No. 85455

SWS:mc sshort

DATED STAMP

Adobe Signature

TABLE OF CONTENTS

INTRODUCTION

PURPOSE AND SCOPE

PROPOSED CONSTRUCTION

SITE LOCATION, SITE HISTORY AND SITE DESCRIPTION

GEOLOGIC SETTING

FIELD AND LABORATORY INVESTIGATIONS

SOIL PROFILE AND SUBSURFACE CONDITIONS

GROUNDWATER

CONCLUSIONS AND RECOMMENDATIONS

Administrative Summary Groundwater Influence on Structures/Construction Site Preparation Slope Construction/Reconstruction Engineered Fill Drainage and Landscaping Utility Trench Backfill Foundations Lateral Earth Pressures and Retaining Walls Seismic Parameters – 2022 CBC Soil Cement Reactivity Compacted Material Acceptance Testing and Inspection

LIMITATIONS

SITE PLANS

LOGS OF BORINGS (1 TO 3) .............................................................................................. Appendix A

GENERAL EARTHWORK SPECIFICATIONS ................................................................Appendix B

September 9, 2024 KA Project No. 052-24055

GEOTECHNICAL ENGINEERING INVESTIGATION

CAMERON CREEK CHECK STRUCTURES

TULARE COUNTY, CALIFORNIA

INTRODUCTION

This report presents the results of our Geotechnical Engineering Investigation for proposed check structure at three locations along Cameron Creek to be located in Tulare County California. Discussions regarding site conditions are presented herein, together with conclusions and recommendations pertaining to site preparation, Engineered Fill, utility trench backfill, drainage and landscaping, foundations, and lateral earth pressures and retaining walls.

Site plans showing the approximate boring locations are presented following the text of this report. A description of the field investigation, boring logs, and the boring log legend are presented in Appendix A. Appendix A contains a description of the laboratory testing phase of this study along with the laboratory test results. Appendix B contains a guide to earthwork specifications. When conflicts in the text of the report occur with the general specifications in the appendices, the recommendations in the text of the report have precedence.

PURPOSE AND SCOPE

This investigation was conducted to evaluate the soil and groundwater conditions at the site, to make geotechnical engineering recommendations for use in design of specific construction elements, and to provide criteria for site preparation and Engineered Fill construction.

Our scope of services was outlined in our proposal dated July 12, 2024 (CTL-Krazan Proposal No. T24- 164CAE) and included the following:

A site reconnaissance by a member of our engineering staff to evaluate the surface conditions at the project site.

A field investigation consisting of drilling 3 borings to a depth of approximately 20.5 feet for evaluation of the subsurface conditions at the project site.

Performing laboratory tests on representative soil samples obtained from the borings to evaluate the physical and index properties of the subsurface soils.

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Krazan & Associates, Inc. dba CTL-Krazan

05224055 Report (Cameron Creek)

Evaluation of the data obtained from the investigation and an engineering analysis to provide recommendations for use in the project design and preparation of construction specifications.

Preparation of this report summarizing the results, conclusions, recommendations, and findings of our investigation.

PROPOSED CONSTRUCTION

We understand that design of the proposed check structures is currently underway; structural load information and other final details pertaining to the structures are unavailable. On a preliminary basis, it is understood that the project involves constructing three concrete structures along Cameron Creek for the purpose of regulating water flow in the creek. The structures will extend no more than ten (10) feet below surface grade.

In the event these structural or grading details are inconsistent with the final design criteria, the Soils Engineer should be notified so that we may update this writing as applicable.

SITE LOCATION, SITE HISTORY AND SITE DESCRIPTION

There are three locations for the project located in channel easements. The first location, B1 (Measurement Check), is approximately 100 ft east of Rd 156 and 0.2 miles south of Ave 292 on the north bank, the second location, B3 (Rector Check), is approximately 0.36 miles south of E. Walnut Ave and 350 ft west of Rd 148 on the west bank, and the third location, B2 (Lovers Lane Check), is approximately 125 ft north of Ave 280 and 100 ft east of Lovers Lane, on the north bank in Tulare County, California. The locations are surrounded by agricultural land.

Site history was obtained by reviewing historical aerial photographs taken in 1994, 2005, 2008 and 2016. From 1994 to 2005 the aerial photography indicates that the project sites were open channel canal structures.

Review of the 2008 aerial photograph indicates that at the project locations an attempt at checking the flow of Cameron Creek appeared and consisted of rubble or rip-rap.

Review of the 2016 aerial photograph indicates that conditions at the project locations continued from 2008. Since 1994 all three locations have been bordered by agriculture primarily consisting of orchards and seasonal crops.

The surface soils have a loose consistency. The locations are relatively level with no major changes in grade.

GEOLOGIC SETTING

The San Joaquin Valley, which includes the Tulare County area, is a topographic and structural basin that is bounded on the east by the Sierra Nevada and on the west by the Coast Ranges. The Sierra Nevada, a fault block dipping gently southwestward, is made up of igneous and metamorphic rocks of

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05224055 Report (Cameron Creek) pre-Tertiary age that comprise the basement complex beneath the Valley. The Coast Ranges contain folded and faulted sedimentary rocks of Mesozoic and Cenozoic age, which are similar to those rocks that underlie the Valley at depth and nonconformably overlie the basement complex; gently dipping to nearly horizontal sedimentary rocks of Tertiary and Quaternary age overlie the older rocks. These younger rocks are mostly of continental origin and in the Tulare County area, they were derived from the Sierra Nevada.

The Kaweah and Tule Rivers are the principal rivers in the area. Alluvial fans formed by these rivers are the largest geomorphic features in the Tulare County area. The formation of the fans has resulted in a rather flat regional topography.

The Coast Ranges evolved as a result of folding, faulting and accretion of diverse geologic terrains.

They are composed chiefly of sedimentary and metamorphic rocks that are sharply deformed into complex structures. They are broken by numerous faults, the San Andreas Fault being the most notable structural feature.

The southern Sierra Nevada represents a tilted fault block composed of a sequence of Mesozoic granitic plutons interspersed with Paleozoic to Mesozoic metamorphic pendants. Mesozoic ultrabasic rocks are present along the western margin of the mountain range.

Both the Sierra Nevada and Coast Range are geologically young mountain ranges and possess active and potentially active fault zones. Major active faults and fault zones occur at some distance to the east, west and south of the Tulare County area. The Owens Valley Fault Zone bounds the eastern edge of the Sierra Nevada block and contains both active and potentially active faults. The San Andreas Fault Zone is located along the Coastal and Diablo Ranges to the west.

Portions of the Ortigalita, Calaveras, Hayward and Rinconada Faults, which are to the west, are considered potentially active. The San Andreas Fault is possibly the best-known fault and is located about 60 to 70 miles to the west.

There are no active fault traces in the project vicinity. Accordingly, the project area is not within an Earthquake Fault Zone (Special Studies Zone).

Tulare County residents could feel the effects of a large seismic event on one of the nearby active or potentially active fault zones. Tulare County has experienced groundshaking from earthquakes in the historical past. According to the Five County Seismic Safety Element, groundshaking of VII intensity (Modified Mercali Scale) was felt in Tulare County from the 1872 Owens Valley Earthquake. This is the largest known earthquake event affecting the Tulare County area.

Secondary hazards from earthquakes include rupture, seiche, landslides, liquefaction, and subsidence.

Since there are no known faults within the immediate area, ground rupture from surface faulting should not be a potential problem. Seiche and landslides are not hazards in the area either. Liquefaction potential (sudden loss of shear strength in a saturated cohesionless soil) should be low since groundwater

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05224055 Report (Cameron Creek) occurs below 50 feet. Lastly, deep subsidence problems may be low to moderate according to the conclusions of the Five County Seismic Safety Element. However, there are no known occurrences of structural or architectural damage due to deep subsidence in the Tulare County area.

FIELD AND LABORATORY INVESTIGATIONS

Subsurface soil conditions were explored by drilling 3 borings to a depth of approximately 20.5 feet below existing site grade, using a truck-mounted drill rig. The approximate boring locations are shown on the site plans. During drilling operations, penetration tests were performed at regular intervals to evaluate the soil consistency and to obtain information regarding the engineering properties of the subsoils. Soil samples were retained for laboratory testing. The soils encountered were continuously examined and visually classified in accordance with the Unified Soil Classification System. A more detailed description of the field investigation is presented in Appendix A.

Laboratory tests were performed on selected soil samples to evaluate their physical characteristics and engineering properties. The laboratory testing program was formulated with emphasis on the evaluation of natural moisture, density, gradation, shear strength, consolidation potential, and moisture-density relationships of the materials encountered. Details of the laboratory test program and results of the laboratory tests are summarized in Appendix A. This information, along with the field observations, was used to prepare the final boring logs in Appendix A.

SOIL PROFILE AND SUBSURFACE CONDITIONS

Based on our findings, the subsurface conditions encountered appear typical of those found in the geologic region of the site. In general, the upper soils consisted of approximately 6 to 12 inches of very loose silty sand or silty sand with trace clay. These soils are disturbed, have low strength characteristics and are highly compressible when saturated.

Approximately 4 feet of fill material was encountered in Boring No. B2 located near the planned Lovers Creek check structure. The fill material predominately consisted of silty sand with clay and gravel. The thickness and extent of fill material was determined based on limited test borings and visual observation.

Thicker fill may be present at the site. Limited testing was performed on the fill soils during the time of our field and laboratory investigations. Preliminary testing indicates that the fill soils have varying strength characteristics ranging from loosely placed to compacted.

Below the loose surface soils and fill material, approximately 3 to 3½ feet of loose to medium dense silty sand, silty sand with trace clay, silty sand/sand and sand were encountered. Field and laboratory tests suggest that these soils are moderately strong and slightly compressible. Penetration resistance ranged from 15 to 39 blows per foot. Dry densities ranged from 107 to 111 pcf. A representative soil sample consolidated approximately 4½ percent under a 2 ksf load when saturated. A representative soil sample had an internal angle of friction of 28 degrees.

Below approximately 4 to 7½ feet, predominately loose to medium dense clayey sand and sand were encountered. Field and laboratory tests suggest that these soils are moderately strong and slightly compressible. Penetration resistance ranged from 11 to 30 blows per foot. Dry densities ranged from 91

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05224055 Report (Cameron Creek) to 107 pcf. Representative soil samples consolidated approximately 2 to 3 percent under a 2 ksf load when saturated. Representative soil samples had angles of internal friction of 30 and 36 degrees. These soils had similar strength characteristics as the upper soils and extended to the termination depth of our borings.

For additional information about the soils encountered, please refer to the logs of borings in Appendix A.

GROUNDWATER

Test boring locations were checked for the presence of groundwater during and immediately following the drilling operations. Free groundwater was encountered at a depth of 18½ feet in Boring No. B3.

Groundwater was not encountered in the other two boring locations.

It should be recognized that water table elevations may fluctuate with time, being dependent upon seasonal precipitation, irrigation, land use and climatic conditions, as well as other factors. Therefore, water level observations at the time of the field investigation may vary from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report.

CONCLUSIONS AND RECOMMENDATIONS

Based on the findings of our field and laboratory investigations, along with previous geotechnical experience in the project area, the following is a summary of our evaluations, conclusions, and recommendations.

Administrative Summary

In brief, the subject site and soil conditions, with the exception of the loose surface soils, fill material and surrounding agricultural development, appear to be conducive to the development of the project.

The surface soils have a loose consistency. These soils are disturbed, have low strength characteristics and are highly compressible when saturated. Accordingly, it is recommended that the surface soils be recompacted. This compaction effort should stabilize the surface soils and locate any unsuitable or pliant areas not found during our field investigation.

Approximately 4 feet of fill material was encountered within Boring No. B2 located near the planned Lovers Creek check structure. The fill material predominately consisted of silty sand with clay and gravel. The thickness and extent of fill material was determined based on limited test borings and visual observation. Thicker fill may be present at the site. Limited testing was performed on the fill soils during the time of our field and laboratory investigations. Preliminary testing indicates the fill soils have varying strength characteristics ranging from loosely placed to compacted. Therefore, it is recommended that the fill soils be excavated and stockpiled so that the native soils can be properly prepared. The fill material should be moisture-conditioned as necessary and recompacted to a minimum of 90 percent of maximum density based on ASTM Test Method D1557. Prior to fill placement, Krazan & Associates, Inc. should inspect the bottom of the excavation to verify no additional removal will be required.

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The three locations presently consist of graded channel embankments. Agricultural developments surround the locations. Associated with these developments are buried structures, such as utility and irrigation lines that may extend into the site. Any buried structures, including utilities or loosely backfilled excavations, encountered during construction should be properly removed and the resulting excavations backfilled with Engineered Fill.

Relatively clean sands were encountered at various locations throughout the site. The possibility exists that site grading operations could expose these soils in areas of proposed buildings, pavements, and/or retaining walls. The Contractor should note that these soils lack the cohesion necessary to stand vertically, even in shallow excavations such as footing trenches. If these conditions are encountered, it will be necessary to over-excavate the affected area(s) to a minimum of 12 inches below the proposed bearing surface. These areas may be backfilled using a mix of the silty sand and sand soils that contains at least 20 percent fines and meeting the requirements for Engineered Fill. This material may be obtained from elsewhere at the site, imported to the site from an approved off-site source, or manufactured through blending of the excavated clean sand with other suitable material containing a higher percentage of fines to result in material meeting the requirements for Engineered Fill.

Sandy soil conditions were encountered at the site. These cohesionless soils have a tendency to cave in trench wall excavations. Shoring or sloping back trench sidewalls may be required within these sandy soils.

After completion of the recommended site preparation, the site should be suitable for shallow footing support. The proposed structure footings may be designed utilizing allowable bearing pressure of 2,500 psf for dead-plus-live loads. Footings should have a minimum embedment of 48 inches below the bottom of the creek due to potential scour.

Groundwater Influence on Structures/Construction

Based on our findings and historical records, it is not anticipated that groundwater will rise within the zone of structural influence or affect the construction of foundations for the project. However, if earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated, “pump,” or not respond to densification techniques. Typical remedial measures include:

discing and aerating the soil during dry weather; mixing the soil with dryer materials; removing and replacing the soil with an approved fill material; or mixing the soil with an approved lime or cement product. Our firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations.

Site Preparation

General site clearing should include removal of concrete; vegetation and existing utilities; trees and associated root systems; rubble; rubbish; and any loose and/or saturated materials. Site stripping should extend to a minimum depth of 2 to 4 inches, or until all organics in excess of 3 percent by volume are removed. Deeper stripping may be required in localized areas. These materials will not be suitable for reuse as Engineered Fill. However, stripped topsoil may be stockpiled and reused in landscape or non-structural areas.

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The three locations presently consist of levee embankment. Agricultural developments surround the locations. Associated with these developments are buried structures, such as irrigation lines that may extend into the project site. Any buried structures, including utilities or loosely backfilled excavations, encountered during construction should be properly removed and the resulting excavations backfilled.

Excavations, depressions, or soft and pliant areas extending below planned finished subgrade levels should be cleaned to firm, undisturbed soil and backfilled with Engineered Fill. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by the Soils Engineer. Any other buried structures should be removed in accordance with the recommendations of the Soils Engineer. The resulting excavations should be backfilled with Engineered Fill.

Approximately 4 feet of fill material was encountered within Boring No. B2 located near the planned Lovers Creek check structure. The fill material predominately consisted of silty sand with clay and gravel. The thickness and extent of fill material was determined based on limited test borings and visual observation. Thicker fill may be present at the site. Limited testing was performed on the fill soils during the time of our field and laboratory investigations. Preliminary testing indicates the fill soils have varying strength characteristics ranging from loosely placed to compacted. Therefore, it is recommended that the fill soils be excavated and stockpiled so that the native soils can be properly prepared. The fill material should be moisture-conditioned as necessary and recompacted to a minimum of 90 percent of maximum density based on ASTM Test Method D1557. Prior to fill placement, Krazan & Associates, Inc. should inspect the bottom of the excavation to verify no additional removal will be required.

It is recommended that following stripping, demolition and fill removal operations, the upper 12 inches of the native soils below bottom of the check structure foundations be excavated, worked until uniform and free from large clods, moisture-conditioned as necessary, and recompacted to a minimum of 90 percent of maximum density based on ASTM Test Method D1557. Over-excavation should extend to a minimum of 5 feet beyond proposed check structure limits. The exposed subgrade soils should be proof rolled and observed by Krazan & Associates, Inc. to verify stability. Soft or pliant areas should be excavated to firm native ground. The excavation should be backfilled with Engineered Fill, compacted to a minimum of 90 percent of maximum density based on ASTM Test Method D1557.

Following stripping, the exposed subgrade within exterior flatwork and pavement areas should be excavated/scarified to a depth of at least 12 inches, worked until uniform and free from large clods, moisture-conditioned as necessary, and recompacted to a minimum of 90 percent (flatwork) and 95 percent (pavement) of maximum density based on ASTM Test Method D1557. Limits of recompaction should extend a minimum of 2 feet beyond flatwork and pavements. This compaction effort should stabilize the surface soils and locate any unsuitable or pliant areas not found during our field investigation.

Relatively clean sands were encountered at various locations throughout the site. The possibility exists that site grading operations could expose these soils in areas of proposed buildings, pavements, and/or retaining walls. The Contractor should note that these soils lack the cohesion necessary to stand vertically, even in shallow excavations such as footing trenches. If these conditions are encountered, it

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05224055 Report (Cameron Creek) will be necessary to over-excavate the affected area(s) to a minimum of 12 inches below the proposed bearing surface. These areas may be backfilled using a mix of the silty sand and sand soils that contains at least 20 percent fines and meeting the requirements for Engineered Fill. This material may be obtained from elsewhere at the site, imported to the site from an approved off-site source, or manufactured through blending of the excavated clean sand with other suitable material containing a higher percentage of fines to result in material meeting the requirements for Engineered Fill.

The upper soils, during wet winter months, become very moist due to the absorptive characteristics of the soil. Earthwork operations performed during winter months may encounter very moist unstable soils which may require removal to grade a stable building foundation. Project site winterization consisting of placement of aggregate base and protecting exposed soils during the construction phase should be performed.

A representative of our firm should be present during all site clearing and grading operations to test and observe earthwork construction. This testing and observation is an integral part of our service as acceptance of earthwork construction is dependent upon compaction of the material and the stability of the material. The Soils Engineer may reject any material that does not meet compaction and stability requirements. Further recommendations of this report are predicated upon the assumption that earthwork construction will conform to recommendations set forth in this section and the Engineered Fill section.

Slope Construction/Reconstruction

Slopes can be reconstructed by placement of Engineered Fill utilizing a keying and benching procedure as described below. Reconstructed slopes should be constructed at an inclination not exceeding 2:1 (horizontal to vertical). Krazan and Associates, Inc. should be retained to review all slope reconstruction plans and specifications prior to initiating the repair work.

General site clearing should include removal of vegetation, any loose and/or saturated materials.

Excavations or depressions extending below subgrade levels should be cleaned to firm, undisturbed soil and backfilled with Engineered Fill, placed and recompacted in accordance with the recommendations stated herein.

Where fills greater than 8 feet are to be constructed on original ground that slopes at inclinations steeper than 6:1 (horizontal to vertical), benches should be cut into the existing slope as the filling operations proceed. Each bench should consist of a level terrace a minimum of 10 feet wide, with the rise to the next bench held to 4 feet or less. Where fills of comparable height will be constructed on ground that slopes at an inclination steeper than 4:1 (horizontal to vertical), a keyway should be provided in addition to the benches. Each keyway should consist of a level trench at least 10 feet wide and at least 2 feet deep, with side slopes not exceeding 1:1 (horizontal to vertical), cut into the existing slope. Where fills of comparable height will be constructed on ground that slopes at an inclination steeper than 2:1 (horizontal to vertical), geotextile fabric and retaining structures should be utilized in slope construction where subsequent specific building site investigations warrant.

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Site grading near the crowns of the reconstructed slopes should be accomplished such that excessive sheet run-off is prevented.

The completed slopes should be seeded or otherwise vegetated to protect from future erosion. Well vegetated slopes at the recommended configuration should be reasonably protected from typical erosional effects. However, vegetated slopes may not be protected from unusual flow conditions, such as flood events or over-topping of the development’s storm drainage system. If erosion control from unusual flow conditions is desired, more substantial erosion protection measures, such as grouted cobble slope facing or manufactured slope protection products should be considered.

Engineered Fill

The on-site, upper native soils are predominately silty sands or sands. These soils will be suitable for reuse as Engineered Fill, provided they are cleansed of excessive organics, debris, and fragments larger than 4 inches in maximum dimension.

Relatively clean sands were encountered at various locations throughout the site. The possibility exists that site grading operations could expose these soils in areas of proposed buildings, pavements, and/or retaining walls. The Contractor should note that these soils lack the cohesion necessary to stand vertically, even in shallow excavations such as footing trenches. If these conditions are encountered, it will be necessary to over-excavate the affected area(s) to a minimum of 12 inches below the proposed bearing surface. These areas may be backfilled using a mix of the silty sand and sand soils that contains at least 20 percent fines and meeting the requirements for Engineered Fill. This material may be obtained from elsewhere at the site, imported to the site from an approved off-site source, or manufactured through blending of the excavated clean sand with other suitable material containing a higher percentage of fines to result in material meeting the requirements for Engineered Fill.

The preferred materials specified for Engineered Fill are suitable for most applications with the exception of exposure to erosion. Project site winterization and protection of exposed soils during the construction phase should be the sole responsibility of the Contractor, since he has complete control of the project site at that time.

Imported Fill material should be predominately non-expansive granular material with a plasticity index less than 10 and an expansion index less than 15. Imported Fill should be free from rocks and clods greater than 4 inches in diameter. All Imported Fill material should be submitted to the Soils Engineer for approval at least 48 hours prior to delivery at the site.

Fill soils should be placed in lifts approximately 6 inches thick, moisture-conditioned as necessary, and compacted to achieve at least 90 percent maximum density as based on ASTM Test Method D1557.

Additional lifts should not be placed if the previous lift did not meet the required dry density or if soil conditions are not stable.

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Drainage and Landscaping

The ground surface should slope away from building pad and pavement areas toward appropriate drop inlets or other surface drainage devices. In accordance with Section 1804 of the 2022 California Building Code, it is recommended that the ground surface adjacent to foundations be sloped a minimum of 5 percent for a minimum distance of 10 feet away from structures, or to an approved alternative means of drainage conveyance. Swales used for conveyance of drainage and located within 10 feet of foundations should be sloped a minimum of 2 percent. Impervious surfaces, such as pavement and exterior concrete flatwork, within 10 feet of building foundations should be sloped a minimum of 1 percent away from the structure. Drainage gradients should be maintained to carry all surface water to collection facilities and off-site. These grades should be maintained for the life of the project.

Utility Trench Backfill

Utility trenches should be excavated according to accepted engineering practices following OSHA (Occupational Safety and Health Administration) standards by a Contractor experienced in such work.

The responsibility for the safety of open trenches should be borne by the Contractor. Traffic and vibration adjacent to trench walls should be minimized and cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation.

Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 90 percent of maximum density based on ASTM Test Method D1557. Utility trench backfill placed in pavement areas should be compacted to at least 95 percent of maximum density based on ASTM Test Method D1557 in the upper 2 ft and 90 percent below the upper 2 ft. Pipe bedding should be in accordance with pipe manufacturer's recommendations.

Sandy soil conditions were encountered at the site. These cohesionless soils have a tendency to cave in trench wall excavations. Shoring or sloping back trench sidewalls may be required within these sandy soils.

The Contractor is responsible for removing all water sensitive soil from the trench regardless of the backfill location and compaction requirements. The Contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction.

Foundations

After completion of the recommended site preparation, the site should be suitable for shallow footing support. The proposed structures may be supported on a shallow foundation system bearing on undisturbed native soils or Engineered Fill. Spread and continuous footings can be designed for the following maximum allowable soil bearing pressures:

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Load Allowable Loading

Dead Load Only 1,500 psf

Dead-Plus-Live Load 2,000 psf

Total Load, including wind or seismic loads 2,650 psf

The footings should have a minimum depth of 48 inches below the bottom of the creek due to potential scour. Footings should have a minimum width of 12 inches, regardless of load. Ultimate design of foundations and reinforcement should be performed by the project’s Structural Engineer.

The total movement is not expected to exceed 1 inch. Differential movement should be less than ½ inch.

Most of the settlement is expected to occur during construction, as the loads are applied. However, additional post-construction movement may occur if the foundation soils are flooded or saturated.

Resistance to lateral footing displacement can be computed using an allowable friction factor of 0.4 acting between the base of foundations and the supporting subgrade. Lateral resistance for footings can alternatively be developed using an equivalent fluid passive pressure of 350 pounds per cubic foot acting against the appropriate vertical footing faces. The frictional and passive resistance of the soil may be combined without reduction in determining the total lateral resistance. A ⅓ increase in the above value may be used for short duration, wind, or seismic loads.

Lateral Earth Pressures and Retaining Walls

Walls retaining horizontal backfill and capable of deflecting a minimum of 0.1 percent of its height at the top may be designed using an equivalent fluid active pressure of 31 pounds per square foot per foot of depth. Walls that are incapable of this deflection or are fully constrained against deflection may be designed for an equivalent fluid at-rest pressure of 52 pounds per square foot per foot of depth.

Expansive soils should not be used for backfill against walls. The wedge of non-expansive backfill material should extend from the bottom of each retaining wall outward and upward at a slope of 2:1 (horizontal to vertical) or flatter. The stated lateral earth pressures do not include the effects of hydrostatic water pressures generated by infiltrating surface water that may accumulate behind the retaining walls; or loads imposed by construction equipment, foundations, or roadways.

During grading and backfill operations adjacent to any walls, heavy equipment should not be allowed to operate within a lateral distance of 5 feet from the wall, or within a lateral distance equal to the wall height, whichever is greater, to avoid developing excessive lateral pressures. Within this zone, only hand-operated equipment (“whackers,” vibratory plates, or pneumatic compactors) should be used to compact the backfill soils.

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Seismic Parameters – 2022 California Building Code

The Site Class per Section 1613 of the 2022 California Building Code (2022 CBC) and ASCE 7-16, Chapter 20 is based upon the site soil conditions. It is our opinion that a Site Class D is most consistent with the subject site soil conditions. For seismic design of the structures based on the seismic provisions of the 2022 CBC, we recommend the following parameters:

Seismic Item Value CBC Reference

Site Class D Section 1613.2.2

Site Coefficient Fa 1.367 Table 1613.2.3 (1)

Ss 0.541 Section 1613.2.1

SMS 0.74 Section 1613.2.3

SDS 0.493 Section 1613.2.4

Site Coefficient Fv 2.168 Table 1613.2.3 (2)

S1 0.216 Section 1613.2.1

SM1 0.468 Section 1613.2.3

SD1 0.312 Section 1613.2.4

TS 0.633 Section 1613.2

* Based on Equivalent Lateral Force (ELF) Design Procedure being used.

Soil Cement Reactivity

Excessive sulfate in either the soil or native water may result in an adverse reaction between the cement in concrete (or stucco) and the soil. HUD/FHA and CBC have developed criteria for evaluation of sulfate levels and how they relate to cement reactivity with soil and/or water.

Soil samples were obtained from the site and tested in accordance with State of California Materials Manual Test Designation 417. The sulfate concentrations detected in these soil samples were less than 150 ppm and are below the maximum allowable values established by HUD/FHA and CBC. Therefore, no special design requirements are necessary to compensate for sulfate reactivity with the cement.

Compacted Material Acceptance

Compaction specifications are not the only criteria for acceptance of the site grading or other such activities. However, the compaction test is the most universally recognized test method for assessing the performance of the Grading Contractor. The numerical test results from the compaction test cannot be used to predict the engineering performance of the compacted material. Therefore, the acceptance of compacted materials will also be dependent on the stability of that material. The Soils Engineer has the option of rejecting any compacted material regardless of the degree of compaction if that material is considered to be unstable or if future instability is suspected. A specific example of rejection of fill

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05224055 Report (Cameron Creek) material passing the required percent compaction is a fill which has been compacted with an in-situ moisture content significantly less than optimum moisture. This type of dry fill (brittle fill) is susceptible to future settlement if it becomes saturated or flooded.

Testing and Inspection

A representative of Krazan & Associates, Inc. should be present at the site during the earthwork activities to confirm that actual subsurface conditions are consistent with the exploratory fieldwork.

This activity is an integral part of our service, as acceptance of earthwork construction is dependent upon compaction testing and stability of the material. This representative can also verify that the intent of these recommendations is incorporated into the project design and construction. Krazan & Associates, Inc. will not be responsible for grades or staking, since this is the responsibility of the Prime Contractor.

LIMITATIONS

Soils Engineering is one of the newest divisions of Civil Engineering. This branch of Civil Engineering is constantly improving as new technologies and understanding of earth sciences advance. Although your site was analyzed using the most appropriate and most current techniques and methods, undoubtedly there will be substantial future improvements in this branch of engineering. In addition to advancements in the field of Soils Engineering, physical changes in the site, either due to excavation or fill placement, new agency regulations, or possible changes in the proposed structure after the soils report is completed may require the soils report to be professionally reviewed. In light of this, the Owner should be aware that there is a practical limit to the usefulness of this report without critical review. Although the time limit for this review is strictly arbitrary, it is suggested that 2 years be considered a reasonable time for the usefulness of this report.

Foundation and earthwork construction is characterized by the presence of a calculated risk that soil and groundwater conditions have been fully revealed by the original foundation investigation. This risk is derived from the practical necessity of basing interpretations and design conclusions on limited sampling of the earth. The recommendations made in this report are based on the assumption that soil conditions do not vary significantly from those disclosed during our field investigation. If any variations or undesirable conditions are encountered during construction, the Soils Engineer should be notified so that supplemental recommendations may be made.

The conclusions of this report are based on the information provided regarding the proposed construction. If the proposed construction is relocated or redesigned, the conclusions in this report may not be valid. The Soils Engineer should be notified of any changes so the recommendations may be reviewed and re-evaluated.

This report is a Geotechnical Engineering Investigation with the purpose of evaluating the soil conditions in terms of foundation design. The scope of our services did not include any Environmental Site Assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater, or atmosphere; or the presence of wetlands. Any statements, or absence of statements, in this report or

Page No. 14

05224055 Report (Cameron Creek) on any boring log regarding odors, unusual or suspicious items, or conditions observed, are strictly for descriptive purposes and are not intended to convey engineering judgment regarding potential hazardous and/or toxic assessment.

The geotechnical engineering information presented herein is based upon professional interpretation utilizing standard engineering practices and a degree of conservatism deemed proper for this project. It is not warranted that such information and interpretation cannot be superseded by future geotechnical engineering developments. We emphasize that this report is valid for the project outlined above and should not be used for any other sites.

If you have any questions or if we may be of further assistance, please do not hesitate to contact our office at (559) 592-3555.

Respectfully submitted, Steven Short Engineering Manager

David R Jarosz, II Managing Engineer RGE No. 2698/RCE No. 60185

SS/DRJ:mc

DATED STAMP

Adobe Signature

Site Location

VICINITY MAP - Not to scale Property located at East of Visalia, CA 93257

APN: N/A

August 16, 2024 SWS CTL-Krazan Project Number 052-24055

R d 156

Lovers Lane

E Caldwell Ave

S C onnor St

Site Location

Site Location

R d 148

BORING MAP - Not to scale Site located 100 ft east of Rd 156, Visalia, CA 93292

GPS: 36.3169144, -119.2242782

August 16, 2024 SWS CTL-Krazan Project Number 052-24055

Boring Locations Soil Sampling

B1

Site located 150 ft west of Lovers Lane, Visalia, CA 93291

GPS: 36.298935, -119.260171

August 16, 2024 SWS CTL-Krazan Project Number 052-24055

B2

Site located at 350 Ft west of Rd 148, Visalia, CA 93291

GPS: 36.307437, -119.244080

August 16, 2024 SWS CTL-Krazan Project Number 052-24055

B3

Appendix A Page A.1

Krazan & Associates, Inc.

APPENDIX A

FIELD AND LABORATORY INVESTIGATIONS

Field Investigation

The field investigation consisted of a surface reconnaissance and a subsurface exploratory program.

Two 6-inch diameter exploratory borings were advanced. The boring locations are shown on the site plan.

The soils encountered were logged in the field during the exploration and, with supplementary laboratory test data, are described in accordance with the Unified Soil Classification System.

Modified standard penetration tests were performed at selected depths. This test represents the resistance to driving a 2½-inch diameter split barrel sampler. The driving energy was provided by a hammer weighing 140 pounds falling 30 inches. Relatively undisturbed soil samples were obtained while performing this test. Bag samples of the disturbed soil were obtained from the auger cuttings. All samples were returned to our Clovis laboratory for evaluation.

Laboratory Investigation

The laboratory investigation was programmed to determine the physical and mechanical properties of the foundation soil underlying the site. Test results were used as criteria for determining the engineering suitability of the surface and subsurface materials encountered.

In-situ moisture content, dry density, consolidation, direct shear, and sieve analysis tests were completed for the undisturbed samples representative of the subsurface material. R-value tests were completed for select bag samples obtained from the auger cuttings. These tests, supplemented by visual observation, comprised the basis for our evaluation of the site material.

The logs of the exploratory borings and laboratory determinations are presented in this Appendix.

UNIFIED SOIL CLASSIFICATION SYSTEM

CONSISTENCY CLASSIFICATION

Description Blows per Foot

Granular Soils Very Loose < 5

Loose 5 – 15 Medium Dense 16 – 40

Dense 41 – 65 Very Dense > 65

Cohesive Soils Very Soft < 3

Soft 3 – 5 Firm 6 – 10 Stiff 11 – 20

Very Stiff 21 – 40 Hard > 40

GRAIN SIZE CLASSIFICATION

Grain Type Standard Sieve Size Grain Size in

Millimeters

Boulders Above 12 inches Above 305

Cobbles 12 to 13 inches 305 to 76.2

Gravel 3 inches to No. 4 76.2 to 4.76

Coarse-grained 3 to ¾ inches 76.2 to 19.1

Fine-grained ¾ inches to No. 4 19.1 to 4.76

Sand No. 4 to No. 200 4.76 to 0.074

Coarse-grained No. 4 to No. 10 4.76 to 2.00

Medium-grained No. 10 to No. 40 2.00 to 0.42

Fine-grained No. 40 to No. 200 0.42 to 0.074

Silt and Clay Below No. 200 Below 0.074

Log of Boring Project No:Project:

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 1 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B1 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-1

Michael Rupright

None None

Ground Surface

SILTY SAND (SM)

Loose, fine- to medium-grained with CLAY; dark brown, moist, drills easily Medium dense below 12 inches

SAND (SP)

Loose, fine- to medium-grained; brown-gray, moist, drills easily

SILTY SAND (SM)

Loose, fine- to medium-grained; brown, damp, drills easily

CLAYEY SAND (SC)

Medium dense, fine- to medium-grained with SILT; dark brown, very moist, drills easily

Fine-grained below 14 feet

107.3

91.7

96.4

91.1

93.2

13.1

4.9

4.9

4.0

15.2

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

8 Inches

David Lopez 20½ Feet

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 2 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B1 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-1

Michael Rupright

None None

End of Borehole

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 1 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B2 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-2

Michael Rupright

None None

Ground Surface

SILTY SAND (SM)

FILL, fine- to medium-grained with CLAY and fine GRAVEL; brown, moist, drills easily With interbeds of SILTY SAND/SAND below 2 feet With GRAVEL at 3 to 5 feet

SILTY SAND (SM)

Medium dense, fine- to medium-grained with trace CLAY; brown, moist, drills easily

SAND (SP)

Medium dense, medium- to coarse-grained with trace CLAY; brown, moist, drills easily

Coarse-grained, with no CLAY below 14 feet

Loose below 19 feet

108.6

111.0

102.7

92.0

101.4

8.5

9.7

4.5

6.7

5.2

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

David Lopez 21½ Feet

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 2 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B2 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-2

Michael Rupright

None None

End of Borehole

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

David Lopez 21½ Feet

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 1 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B3 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-3

Michael Rupright

20 Feet 18½ Feet

Ground Surface

SILTY SAND (SM)

Loose, fine-grained with trace CLAY;

dark brown, moist, drills easily

SILTY SAND/SAND (SM/SP)

Loose, fine- to medium-grained; gray-brown, moist, drills easily

SAND (SP)

Medium dense, fine- to coarse-grained;

brown, damp, drills easily

Medium dense below 4 feet

Saturated at approximately 20 feet

100.0

106.9

100.3

5.5

3.6

11.2

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

Client:

Location:

Figure No.:

Logged By:

Depth to Water> Initial: At Completion:

Drill Rig:

Drill Method: Drill Date:

Hole Size:

Driller: Elevation:

Sheet: 2 of 2

Krazan and Associates

SUBSURFACE PROFILE SAMPLE

D e p th ft

S ym b o l

Description

D ry

D e n si ty p cf

M o is tu re

T yp e

B lo w s/ ft

Penetration Test blows/ft

Water Content (%)

B3 052-24055Cameron Creek

Provost & Pritchard Consulting Group

Caldwell Avenue, Visalia, California

A-3

Michael Rupright

20 Feet 18½ Feet

End of Borehole

20 40 60 10 20 30 40

B80

Hollow Stem 7-12-24

PROJECT: Soils Investigation for PROJECT NO: 052-24055 Cameron Creek Visalia, Ca. DATE RECEIVED: 07/19/2024

TABLE 1

IN-SIT…