Laserfiche WebLink
File No. 20-3668-01 k%J K L E I N F E L D E R <br /> January 7, 1993 <br /> With the above provisions, we recommend a maximum allowable bearing pressure of 2,000 <br /> pounds per square foot (psf) for dead plus live loads be used in design. This value can be <br /> increased by 1/3 for the total of all loads, including wind and seismic forces. With foundations <br /> supported on compacted existing soils, the anticipated total settlement is less than 'h inch. <br /> Differential settlement can be assumed to be approximately 'h this value. The majority of the <br /> settlement should occur during construction as building loads are placed, provided foundations <br /> are not exposed to sustained standing water or flooding. <br /> If a higher bearing pressure is desired, structures can be supported on a minimum of 2 feet <br /> of Engineered Fill beneath the foundations. We recommend the Engineered Fill extend at <br /> least 2 feet beyond the foundations in order to provide more uniform support to the <br /> foundations. With these provisions, the maximum bearing pressure can be increased to 3,000 <br /> psf for dead plus live loads, with a '/s increase for the total of all loads, including wind and <br /> seismic forces. With structures supported on 2 feet of Engineered Fill beneath the <br /> foundations, and for column loads of approximately 50 kips, we anticipate that settlement will <br /> be less than lk inch. <br /> We recommend that the reinforcing and foundation design be provided by the structural <br /> engineer. We note that the above-stated bearing pressures are net values, and the weight of <br /> concrete in the portions of the foundations which extend below grade can be neglected in <br /> proportioning the foundations. <br /> Excavations <br /> Because of the general sandy nature of the soils at the site, we recommend that all excavations <br /> extending to depths greater than 5 feet be shored according to OSHA approved standards. <br /> Should temporary excavations be planned which make shoring difficult or impossible, we <br /> recommend that excavation side walls be sloped to an angle of no steeper than 1:1 (horizontal <br /> to vertical) for excavations to 30 feet in depth. Even flatter slopes, such as 11h:1 or 2:1 <br /> (horizontal to vertical) may be needed for temporary slopes should clean sand be encountered. <br /> Should any excavation be planned to extend greater than 30 feet in depth, we recommend that <br /> our firm be contacted prior to construction for further consultation as the excavation proceeds. <br /> Caution: Groundwater was encountered at depths of 27.5 to 30 feet at the site. We note that <br /> some water mitigation due to interception with groundwater may be necessary in deep <br /> excavations. Groundwater control measures may vary from dewatering wells to simple sumps <br /> installed at the base of excavations which are periodically pumped according to water <br /> infiltration rates. <br /> Copyright 1993 Kleinfelder, Inc. Page 5 of 11 <br />