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Opportunity Zone Development LLC <br />June 5, 2019 <br />JN 191U <br />Page 7 <br />economical than cantilevered walls where the depth of excavation Is greater than about 15 <br />feet. <br />Soldier Pile Installation <br />Soldier pile walls would be constructed after making planned cut slopes, and prior to <br />commencing the mass excavation, by setting steel H-beams in a drilled hole and <br />grouting the space between the beam and the s ill with concrete for the entire height <br />of the drilled hole. The contractor should be prepared to case the holes or use the <br />slurry method U caving soil is encountered. Excessive ground lose in the drilled <br />holes must be avoided to reduce the potential for settlement on adjacent properties. <br />If water is present in a hole at the time the soldier pile is poured, concrete must be <br />berried to the bottom of the hole. <br />As excavation proceeds downward, the space between the piles should be lagged <br />Min timber, and any voids behind the Umbers should be filled with pea gravel, or a <br />slurry comprised of sand and fly ash. Treated lagging is usually required for <br />permanent walls, while untreated lagging can often be utilized for temporary shoring <br />walls. Temporary vertical cuts will be necessary between the soldler piles for the <br />lagging placement. The prompt and careful installation of lagging is important, <br />particularly in loose or caving soil, to maintain the integrity of the excavation and <br />provide safer working conditions. Additionally, care must be taken by the excavator <br />to remove no more soil between the soldier piles than Is necessary to install the <br />lagging. Caving or overexcavaflon during lagging placement could result in loss of <br />ground on neighboring properties. Timber lagging should be designed for an applied <br />lateral pressure of 30 percent of the design wall pressure, if the pile spacing is less <br />than three pile diameters. For larger pile spacings, the lagging should be designed <br />for 50 percent of the design load. <br />Soldier Pile Wall Design <br />Temporary soldier pile shoring that is cantilevered or restrained by one new of <br />tiebacks, and that has a level backslope, should be designed for an active soil <br />pressure equal to that pressure exerted by an equivalent fluid with a unit weight of <br />25 pounds per cubic foot (pcf). Five (5) pot should be added to this active pressure <br />of the wall is considered permanent. If two or more tie -back anchors are used, a <br />temporary pressure of 17H (where H is the wall height) should be used. Plate 7 <br />attached to this report presents design Considerations for soldier pile shoring that Is <br />cantilevered or restrained by one row of tiebacks. General considerations for the <br />design of fled -back anchors or braced soldier -pile walls where two or more anchors <br />or braces are used are presented on Plate 8. <br />Traffic surcharges can typically be accounted for by Increasing the effective height of <br />the shoring wall by 2 feet. The existing southern adjacent building will exert a <br />surcharge on the proposed southern shoring wall and permanent southern <br />foundation wall, unless the adjacent building Is underpinned — as noted in the <br />General section, more Information should be obtained to determine the surcharge <br />pressure of this building If it is not underpinned. Soldier piles are a viable option to <br />use as underpinning. Slopes above the shoring walls will exert additional surcharge <br />pressures. These surcharge pressures will vary, depending on the configuration of <br />the cut slope and shoring wall. <br />GEOTECH CONSULTANTS, INC. <br />