11229 19TH AVE SE SILVER LAKE TOWNHOMES WHOLE SITE Geotech Report 2022-10-25

Geotechnical Report Proposed Development: 11229 - 19th Avenue SE, Everett, WA September 16, 2016 Table 2 - Summary of Commonly-Accepted Driving Criteria for 3- or 4-inch Pin Pile with a 6 and 10-ton Allowable Axial Compression Load Hammer 3"Pile Refusal 4" Pile Refusal Hammer Weight(lb)/ Criteria Criteria Model Blows per (seconds per inch (seconds per inch minute of penetration) of penetration) Hydraulic TB 850/900 10 16 325 Hydraulic TB 1,100/900 6 10 425 Hydraulic TB 2,000/600 3 4 725X Please note that these refusal criteria were established empirically based on previous load tests on 3- and 4-inch pin piles. Contractors may select a different hammer for driving these piles, and propose a different driving criterion. In this case,it is the contractor's responsibility to demonstrate to the Engineer's satisfaction that the design load can be achieved based on their selected equipment and driving criteria. Pin Pile Specifications - We recommend that the following specifications be included on the foundation plan: 1. Three-, four-, or six-inch diameter piles should consist of galvanized Schedule-40, ASTM A-53 Grade "A" pipe. 2. The piles shall be driven to refusal as shown in Table 2 above. 3. Piles shall be driven in nominal sections and connected with compression fitted sleeve couplers (see detail below—Courtesy of McDowell Pile King, Kent, WA). We discourage welding of pipe joints, particularly when galvanized pipe is used, as we have frequently observed welds broken during driving. 4. The geotechnical engineer of record or his/her representative shall observe pin pile installation. 16-210 11229 19th Ave SE Rpt Page 8 PanGEO, Inc.