1001 E MARINE VIEW DR SITE WORK AND UTILITIES 2018-01-01 MF Import

SteHen Jacobson JN 96313 August 17, 1998 Page 7 Cantilevered and Tied-Back Soldier File Walls Cantilevered and tied-back soldier pile shoring systems nave proven tu be an efficient and economical method for providir:g excavation shoring. T.ed-back walls are typicaily more economical than cantilevered wall�a where the depth of excavat:on is greater than 15 feet. Soldier Pile Installation Soldier pile walls would be constructed prior to commencirg the excavation by setti�ig steel H-beams in a drilled hole and grouting the space berive�n the beam and the soil with concrete for the entire height of the drilled hole. We anticipate that the holes could be drilled without casing, but the contractor should be prepared to case the holes or use ihe slurry method if caving soil is encountered. Excessive ground loss in the drilled holes must be avoided to reduce the potential tor settlement on adjacant properties. If water is present in a hole at the time the soldier pile is poured, concrete must be tremied to tlie bottom of the hale. As excavation proceeds downward, the space betweer� the piles should be lagged with treated timber, and any voids behind the timbers should be filled with pea gravel or a sand and fly ash slurry. The prompt and careful installation of lagging is important, particularly in loose or caving soii, to maintain the integrity of the exczvation and provide safer working conditions. Additionally, care must be taken by the �xcavator to remove no more soil between the soldier piles than is necessary to install the Iagging. Caving or overexcavation during lagging placement could result in loss of ground on neighboring properties. 1. For the excavation depths anticipated and with pile spacings of about 6 feet, nominal 4-inch lagging can be used. 2. Timber lagging should be designed for an applied lateral pressure of 30 percent of the design wall pressure, if the pile spacing is less than three pile diameters. For larger pile spacings, the lagging sr,ould be designed for 50 percent of the design load. if permanenl building walls are to be constructed against the shoring walls, drainage should be provided by attaching a geotextile drainage composite with a solid plastic backing, similar to Miradrain 6000, to the face of the lagging, prior to pouring the foundation wall. These drainage composites should be hydraulically connected to the foundation drainage system through weep holes piaced in the foundation walls. Soldier Pile Wali Design Temporary cantilevered shoring with a level backslope should be designed for an active soii pressure equal to that pressure exerted by an equivalent fluid with a unit weight of 30 pcf. A surcharge of 15H psf should be added to the active pressure for 1:1 (H:V) slopes above shoring walls, where it is the height of the slope. Traffic surctiarges can be accounted for by increasing the effective height of the shoring wall by 2 feet. Lateral movement of the soldier piles below the excavation level will be resisted by an allowable passive soil pressure equal to tfiat pressure exerted by a fluid with a density of ��r,<rrna i co��,�.r:��r�.i��