Laserfiche WebLink
CITY OF SANTA ANA <br />Planning and Building Agency <br />Geotechnical Conditions <br />The subject property is not located within a potential liquefaction <br />subsurface geotechnical investigation to deal with the potential <br />considered necessary for this proposed ADU project. <br />Approved <br />FOR PERMIT ISSUANCE <br />�j�ster�IDo <br />IS M <br />The subject site is a previously graded lot where a house exists. The underlying soils <br />were previously properly treated, as necessary, and previously evaluated to be suitable <br />for structural support prior to approval for construction of the existing house. Distress <br />to the existing house due to settlement and/or any other geotechnical issues was not <br />observed / reported. Therefore, drilling a deep test hole, sampling, and performing <br />consolidation testing for evaluation of the potential deep-seated settlement of the <br />underlying soils is not considered necessary for this project. <br />To verify the near ground surface soils, a 5 ft. deep test hole has been drilled using a <br />hand-held drilling tool and soil samples were collected for laboratory testing. The <br />approximate location of the test hole is depicted on the Site Plan / Geotechnical Map. The <br />geotechnical boring log and summary of results of the laboratory testing are included in <br />Appendix B. <br />Based on our field observation and testing, the near -ground surface soils at the site <br />generally consisted of silty fine sand with minor clay and fine gravel, moist, medium <br />dense, and have a very low expansion potential. <br />C1rni111dx ntPr <br />Free standing groundwater was not encountered in our test hole. <br />Based on the "Historically Highest Ground Water Contours and Borehole Log Data <br />Locations, Orange Quadrangle", Plate 1.2 of the Open -File Report 97-19 prepared by <br />California Division of Mines and Geology (CDMG), Department of Conservation, the <br />historically highest groundwater level at the subject site is about 40 ft. below the ground <br />surface. <br />Free standing ground water was not reported to be an issue at the site and in the vicinity. <br />Deep footings/excavations are not proposed for the site; therefore adverse effects due to <br />groundwater are not anticipated for the proposed development. <br />Note: it is not anticipated; however, if wet soils are encountered, removal of the wet soils <br />and replacement with drier soils/cement slurry can be performed. In addition, if needed, <br />crushed rock and or geogrids for bridging, etc. can also be used. This will be determined <br />by the geotechnical consultant based on the exposed conditions during the excavations at <br />the site. <br />Page 2 <br />