1004 BROADWAY EVCC STUDENT HOUSING - REPORTS & FINAL DOCUMENTS 2017-01-13

Geotechnical Report - �:� : ised Proposed Apartments: 1002, 1006, and 1008 Broadway Street, Everett, Washington May 12, 2015 4.5 PERMANENT CUT AND FILL SLOPES Based on the anticipated soil that will be exposed in the planned excavation, we recominend permanent cut and fill slopes be constructed no steeper than 2H:1 V (Harizontal: Vertical). 5.0 TEMPORARY EXCAVATIONS AND SHORING In order to achieve constrLiction subgrade elevations, an excavation extending to about 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. It is planned to accomplish the excavation as a conventional open cut with temporary side slopes. However, depending on the final configuration of the excavation, shoring may be needed for the south side of the excavation. S.1 TEMPORARY EXCAVATIONS Temporary excavations should be constructed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for inaintaining safe excavation slopes and/or shoring. We anticipate the excavation will encounter two to three feet of weathered till consisting of inedium dense sand with gravel overlying unweathered till comprised of very dense silty sand with gravel. Based on these conditions the buildin� excavation can be 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. Temporary excavations should be evaluated in the field during construction based 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 suff cient room to maintain the excavation within the limits of the property, teinporar•y easements may be needed to slope the excavatioil into the adjoining properties. If easements cannot be obtained, then temporai•y shoring may be needed� I>-048 IOOS t3roachca��. Reviscd Pc��E 1 n P�nGBO; InC.