1934 GRAND AVE 2016-01-01 MF Import

.__, � • Carl Pearson JN 95068 February 20, 1995 Page 3 which results in occasional snallow ravelling or sloughing. Deep instability in these granular soiis is uncommon. No seepage was observed in our previous test pit, during the drilling of the piers for the adjacent addition, or on the slope below the site. G4NQl.5J_$19NS_AND RECQMMENDATIONS SQnsr�l Based on the observaUons made during our recent site visit and our previous study on the adJacent lot, It is our opinion that the construction of the proposed triplex is feasib�e from a geotechn(cal englneering standpoint. The medium-dense to dense sands that underlie the site are competent and suitable to support the buildfng on conventional toundations. How- ever, the steep, westem slope is standing near the angle oi repose for these native soils, which results in occasional shailow sloughing. Due to the height of the bank, it appears Impractical to stop this natural process from continuing. Therefore, the structure must be designed so it is not damaged by future shallow slope movement. Based on our ob�erva- tions, it eppears that the recession rate of the slope is very slow. We rocommend suppoRing any foundations thet are located within 15 feet of the steep slope's crest on drilled piers. This recommendation is similar to what we recommended for the adjacent northem remo�iel project. Tho small deck on the western side of the proposed building may settie or be damaged if it is supported on conventiona!footings. Information regarding deteiled topography and planned finish iloor elevations was not avail- able at the time of this report. It appears that the excavations necessary to construct the basement garage will be deepest along the northern and eastern sides. The foundations and the driveway tor the adjacent northem house are along the northern side. The adjacent foundatlons extend down to the basement level, and they should not be affected by the planned excavation on the subject site. However, the driveway is 7 to e feet above the planned bottom of the excavation. Cuts for the proposed building showd not extend below a 1:1 (Horizontal:Vertical) zone starting at the edge of the adjacent driveway. If a 1:1 (H:V) temporary cut along the eastem side would undermine the existing sidewalk, an ecology block wall up to 5 feet in height could be used as temporary shoring. This type oi wall would be constructed by burying the lowest row of blocks at least 12 inches beloK the bottom of the excavation. The block wall should be battered at an inclination of about 1:6 (H:� and placed directly against cut soils. These walls should never be built in front of loose soiis or fill. Pea gravel can be used to fill any small voids between the ecology blocks and the cut face. � GIiO'IliCl l CONtiUI:fAN'1\.INC. �