2721 WETMORE AVE MARQUEE APARTMENTS 2023-06-28

Subsurface Exploration, Geologic Hazard, and 2721 Wetmore Preliminary Geotechnical Engineering Report Everett, Washington Preliminary Design Recommendations and south should also be included in the design. This section of the report presents preliminary design considerations and criteria for use in the design of the excavation shoring. With this information and other pertinent data, it should be the responsibility of the structural engineer or shoring subcontractor(s) to determine the appropriate design details, construction methods, and procedures for installation of the shoring system. 13.1 Soil Nailing Considering the generally competent nature of the on-site soils, soil nails may prove more economical and less restrictive than conventional soldier piles and tiebacks. This section of the report presents preliminary design considerations and criteria that should be considered in the design of soil nail-supported excavation shoring. AESI does not provide soil nailing design drawings. We rely on experienced professional designers and contractors to provide the design drawings and details necessary to obtain permits. AESI can, however, provide the required inspection and monitoring of proof-testing to satisfy City of Everett requirements. The following report sections provide the basic information for the site soils to be used in a soil nail wall design. The final design should satisfy the criteria presented in this report, moment equilibrium, and installation and performance criteria required by the City of Everett for temporary soil nail-supported wall construction. Soil nailing consists of installing a grid pattern of grouted rebar tendons ("nails") into slightly inclined drilled holes spaced on a vertical soil cut face as excavation proceeds. The soil nail tendons are typically shorter in length than conventional tieback anchors. This produces a reinforced zone that is itself stable and helps to support the unreinforced ground behind it. The nails are passive, in that they are untensioned at the time of installation; over time, they become tensioned as they resist the deformation of the adjacent soil. The nail reinforcement improves stability in two ways. First, soil nails reduce the driving force along potential failure surfaces. Second, in frictional soils, nails increase the normal force and hence the soil shear resistance along potential slip surfaces. Wire mesh reinforcement and rebar are attached to the nails and the face of the excavation is covered with a suitable thickness of air-placed concrete (shotcrete). The advantages of this 'f technique over shoring that utilizes soldier pile walls is that the shotcrete wall can serve as the 1 wall of the excavation without the need for deep piles and lagging, it can be constructed while above-grade work proceeds, and the wall can consist of either the temporary shoring wall alone or it can be incorporated into the permanent basement wall, providing the potential for significant cost savings. Due to the depth of excavation at this site, it would be necessary to first construct the soil nail shoring, then build the structure wall from the bottom up versus J using the shoring as the permanent basement wall (top down construction). May 28, 2019 ASSOCIATED EARTH SCIENCES,INC. FSM/Id-.190168E001-2-Projects\20190168\KE\WP Page 13 18185E Page 8 of 180