2106 GRAND AVE 2016-01-01 MF Import

i GEOTECHINUL ENGINEERING STLDV E-12863 1 Marth 17, 2007 � Based on the results of our laboratory tests, at the time of our exploration, the soiis i encountered on site are suitable for use as structural fill provided grading operations take place in dry weather. The soils encountered during our exploration were observed to have be � high in moisture and may require moisture conditioning prior to use as structural fill. Based on i observed conditions, the site soils have a high fines content in excess of 90 percent fines passing the U.S. No. 200 sieve. Soil with fines in excess of approximately 5 percent wiil i degrade if exposed to excessive moisture. Soils with a very high fines content are very likaly � to be difficult to place. If using these soils for structural fill, it will be necessary to monitor soil moistures to maintain them close to the optimum conditions. I If the existing soils cannot be moisture conditioned, it may be necessary to import soil to use for structural fili. Imported soil intended for use as structural fill should consist of a fairly well- igraded granular soil with a moisture content that is at or near its optimum moisture content and has a maximum aggregate size of 4 inches. During wet weather conditions or where groundwater seepage is encountered, structural fill should consist of a fairly well-graded I grenular materiai having a maximum aggregate size of 4 inches and no more than 5 percent � fines passing the U.S. No. 200 sieve. � Shoring Recommendations I Due to the anticipated depth of the proposed building excavation, and due to the proximity of � the cut to adjacent property lines, shoring will be necessary to support the proposed cuts. For the purpose of this study, recommendations for shoring consisting of cantilever soldier piles with wood lagging are provided. I ' Soldier Piles and Lagging iWe understand that cantilevered soldier pile walls with lagging will be used to support the excavation. Based on information provided, the soldier piles will consist of 6-inch driven piles. , Pile Design. Temporary walls should be designed to resist the lateral earth pressures imposed by an enuivalent fli!id with a unit weight of 35 pcf in the exposed height of the wall. � Lagging Design. For temporary shoring, the earth pressure between the soldier piles can be reduced by one•half to account for soil arching in the lagging design. The lagging should be � backfilled with a free-draining soii. The lagging shouid be installed progressively and � backfilled as the excavation deepens to limit the potential for sloughing of the excavation. I Lateral Resistance. Lateral restraint at the bottom of the shoring walls will be provided by passive soil pressure against the embedded length of the soldier piles beneath the bottom of the excavation. A passive resistance of 400 psf along the embedded portion of the pile, I neglecting the upper 2 feet, should be used for design. The passive resistance should be applied to 2.0 times the soldier pile diameter, I Mobilization of the full passive pressure assumes the ground surface inside the excavation wili be horizontal for a distance of at least 4 times the depth of the soldier pile penetration. ECI should be contacted to provide revised design values if chis is not the case. IEARTH CONSULTING INCORPORqTED Paae i