1004 BROADWAY EVCC STUDENT HOUSING - PUBLIC WORKS 2017-01-13

Geotechnical Report - Revised Proposed Apartments: 1002, 1006, and ] 008 Broadway Street, Everett, Washington May 12, 2015 _ 4.S PERMANENT CUT AND FILL SLOPES Based on the anticipated soil that wikl be exposed in the planned excavation, �ve reconmlend pei•manent cut and fill slopes be constructed no steeper than 2H:1 V {Horizontal: Vertical). 5.{) T�MP012r1RY CXCAVA`CIONS ANll SIIDKING In order to achieve construction subgrade efevations, an cxcavation extending to a�bout 10 feet below existing grade is planned. The excavation will extend to within about five feet of the south property line, 25 feet of the west property line, 17 feet of the north property line, and 2 feet of the east property line. Ii is platu�ed to accomplish the excavation as a conventional open cut with temporary side slopes. However, depending on the final configuration of tl�e excavation, shoring may be needed foi• ttie south side of the excavatlon. 5.1 T�:NiPpRARI' EXCAVATIONS Temporary excavations should be coiisti-ucted ili accordance with Part N of WAC (Washington Administrative Code) 296-155. 7'he contractor is i•esponsible for maintaining safe excavation slopes and/or shoring. We anticip�te the excavation will encounter two to tiu�ee fect of weathered t.ilr consisting of inedium dense sand with gravel overlying unweathered till comprised of very dense silty sand with gravel. Based on these conditions the building excav��tion can bc accomplished as an open cut with a 3/4H:1 V inclination. An L-shaped footing may be used to conserve space for temporary excavations. "I'emporary excavations should be evaluated in the field during construction base� on actual observed soil conditions. If seepage is encountered, excavation slope inclinations may need to be reduced. During wet weather, the cut slopes may need to be flattened to reduce potential erosion or should be covered with plastic sheeting. If there is not sufficient room to maintain the excavation within the limits of the property, temporary casements may be needed to slope the excavation into the adjoining propei-ties. If easements cannot be abtained, then temporary shoring may be naeded. I 5-043 1003 Broadway, Revisec� PflgE 1 Q PanGEO, InC.