SU0014056 - Laserfiche WebLink

Home Browse Search

Geotechnical Engineering Investigation Page 18 of 24 New Residential Subdivision 2706 Pock Lane Stockton, CA 95205 March 30, 2021 CTE Job # 25-1097G against a properly drained and backfilled cantilever retaining wall above the groundwater level can be expressed as: PAE=PA+APAE For non-yielding (or"restrained")walls,the total lateral thrust may be similarly calculated based on work by Wood(1973): PKE=PK+APKE Where PA=Static Active Thrust(given in previous Table) PK= Static Restrained Wall Thrust(given in previous Table) APAE=Dynamic Active Thrust Increment=(3/8)kh yH2 APKE=Dynamic Restrained Thrust Increment=kh yH2 kh= '/2 Peak Ground Acceleration= '/2(SDs/2.5) H=Total Height of the Wall y=Total Unit Weight of Soil z 125 pounds per cubic foot The increment of dynamic thrust in both cases should be based on a trapezoidal distribution (essentially an inverted triangle),with a line of action located at 0.6H above the bottom of the wall. The values above assume non-expansive backfill and free-draining conditions. Additional information for dynamic and static loading conditions for specific retaining structures can be provided on request from CTE. Measures should be taken to prevent moisture buildup behind all retaining walls. Drainage measures should include free-draining backfill materials and sloped, perforated drains. These drains should discharge to an appropriate off-site location. Waterproofing should be as specified by the project architect. 5.7 Foundation Setback The bottoms of all utility trenches placed along the perimeter of the foundations should be above an imaginary plane that projects at a 45-degree angle down from the lowest outermost edge of the foundation. Where the trench passes through the plane, it should be installed perpendicular to the face of the foundation for a distance of at least the depth of the foundation. All footings should be offset from descending slopes a minimum distance of 10 feet. Deepening of affected foundation is considered an effective means of attaining the prescribed setbacks.