3121 8TH ST AB 2016-01-01 MF Import

Junc l, 2008 Duplex I3uilding L�A Job No. AA05> 1'agc 5 GROUNllWA"I'I?!2 CONUI'i'ION Groundwater seepage was encauntered in any of the four tcst pits exclvatcd on ihe sitc. Thc very-dense, weakly-cemented, fresh Vaehon till deposit underlying the site at shallow depth is of extremely low permeability, and would perch stormwater infiltrating into thc more penneabic surficial soils. The amount of and the depth to the nenr-surrace perched groundwater would tluctuate seasonally, depending on precipitation, surfacc runoff, ground vegetation rover, site ulili•ration, and other factors. This perched groundwater may dry up compl�tely during the drycr summer �uonths and accumulate and rise in the wet winter months. llISCUSSIONS AND RGCOMMCNDATIONS G�NCRAL I3ascd on thc soil conditions encountered in tlie site subsurfacc explor:itions, it is our opinion that the site is suitable for the proposed devclopment from the geotechnical engineering viewpoint, provided that the recommendations in this repori are fully implemented and observed during construction. Due to sensitive natwr of the steep slope (lanking the east side of the site. wc recommend that grading and foundation const�vction «�ork (or tfie proposed duplex buiiding be c�rried out and completed during the dryer period from April 1 to October 31. If work has to procced in the wetter months beyond this dryer period, the measures recommended in tliis report for slope stabilization, erosion mitigation cmd drainage control should be in place and operational on a daily basis during construction. The surficial fill and topsoil should be stripped down to medium-dense weathered soils witliin the driveway, :�nd the surficial fill a�id topsoil and wcathered soils should be stripped do�vn to very-dense fresh till soils within the building pads. The un�erlying fresh till soils are of high sliear strcngth and are capablc of� providing exccllent Coundation support to ilie proposed duples building. LIU & ASSOCIATES, iNC.