2631 WALNUT ST JACKSONS Geotech Report 2025-07-28

1 Jackson's aka PacWest Energy LLC JN 13465 ' December 9, 2013 Page 3 CONCLUSIONS AND RECOMMENDATIONS ' GENERAL ' THIS SECTION CONTAINS A SUMMARY OF OUR STUDY AND.FINDINGS FOR THE PURPOSES OF A GENERAL OVERVIEW ONLY. MORE SPECIFIC RECOMMENDATIONS AND CONCLUSIONS ARE CONTAINED IN THE REMAINDER OF THIS REPORT. ANY PARTY RELYING ON THIS REPORT SHOULD READ THE ENTIRE DOCUMENT. The test borings conducted for this study encountered loose fill that extended to depths of up to about 5 feet in the planned convenience store location. These fill materials are not suitable for support of the planned convenience store. Excessive differential settlement would result if the footings are not excavated through the fill. The structure's foundations should extend to the medium-dense silty sand with gravel encountered below the fill. This includes "thickened edge" slabs, which really Just shallow footing. The explorations in the vicinity of the planned canopy in the west central portion of the site encountered native medium-dense soil at shallow depths. ' Where overexcavation below planned footing grades is necessary either the footings can be extended downward or the overexcavation could be backfilled with structural fill. This is discussed in Conventional Footings. ' The proposed convenience store location partially overlies the area of the existing USTs. When these USTs are removed, placement of structural fill within that excavation should take place under the direction of a geotechnical engineer. it will be important that all loose soils be removed and/or ' recompacted prior to backfllling up to the foundation grades with structural fill. Due to the complexity of the soil conditions at the planned convenience store location, Geotech ' Consultants,. Inc. should be retained to provide geotechnical consultation services during construction. If another firm is retained to observe project earthwork activities, that firm would be responsible for assessing the bearing conditions, as well as the extent of overexcavation and ' backfill in structural areas. The on-site soils are generally silty and moisture sensitive, and some of the near surface soils are wet. It would be feasible to use the on-site soils as structural fill only during hot, dry weather, when drying the wetter soil by aeration is possible. Due to the significant silt content and dense nature of the native site soils, infiltration of stormwater is not feasible at the site. The erosion control measures needed during the site development will depend heavily on the weather conditions that are encountered. The area of clearing should be as limited as possible, as maintaining existing pavements and landscaping will help reduce the potential for erosion control problems. We anticipate that a silt fence may be needed around the downslope sides of any ' cleared areas. Cut slopes and soil stockpiles should be covered with plastic during wet weather. On-site catch basins should be protected for soil and/or debris that may fall into them during demolition and site earthwork. Following rough grading, it may be necessary to mulch or ' hydroseed bare areas that will not be immediately covered with landscaping or an impervious surface.