933 S Harmon St Unit #2 - Plan - Laserfiche WebLink

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CITY OF SANTA ANA Planning and Building Agency April 16, 2025 Page 5 Project umber 25129-25 Approved FOR PERMIT ISSUANCE 6.0 Liquefaction Evaluation The site is expected to experience ground shaking and earthquake activity & dIiattoVal of the Southern California area. It is during severe shaking that loose, granul P98% below the groundwater table can liquefy. Based upon information in the California Division of Mines and Geology "Seismic Hazard Zone Map — Newport Beach Quadrangle" dated April 17, 1997, the subject site is situated within an area of historic occurrence of liquefaction, or local geological, geotechnical and groundwater conditions to indicate a potential for permanent ground displacement. The amount of seismic -induced settlements during a local magnitude 6.9 earthquake would require a 50 feet deep boring, which is beyond the scope of this report. Differential building settlements may occur after an earthquake and may cause minor cracks and distress in the walls and ceilings. Therefore, a stiffened foundation system should be utilized for the proposed construction to help mitigate the effects of liquefaction. The stiffened system may consist of a post -tensioned slab design, mat foundation or a system of grade beams connecting the foundations in two directions throughout the new construction areas. 7.0 Conclusions and Recommendations Based upon our evaluations, the proposed development is acceptable from a geotechnical engineering standpoint. By following the recommendations and guidelines set forth in our report, the structures will be safe from excessive settlements under the anticipated design loadings and conditions. The proposed development shall meet all requirements of the City Building Ordinance and will not impose any adverse effect on existing adjacent structures. The following recommendations are based upon soil conditions encountered in our field investigation; these near -surface soil conditions could vary across the site. Variations in the soil conditions may not become evident until the commencement of grading operations for the proposed development and revised recommendations from the soils engineer may be necessary based upon the conditions encountered. It is recommended that site inspections are performed by a representative of this firm during all grading and construction of the development to verify the findings and recommendations documented in this report. The following sections present a discussion of geotechnical related requirements for specific design recommendations of different aspects of the project. NorCal Engineering