8407 BROADWAY SECURE SPACE STORAGE Geotech Report 2025-04-24

Zi pperGeo Broadway Everett Expansion Geoprofessional Consultant, Project No. 2601.01 July 7, 2022 Axial Compressive Capacity Table Pipe Size Min. Min. Wall Hammer Size Allowable Axial Compressive (in) Outside Thickness Capacity* Diameter (in) (actual weight in lbs.) (in) (kips) 2 2.375 .218 90/ 140/400/650 6 3 3.50 0.216 400/650/850/1100/2000 12 4 4.50 0.237 850/1100/2000 20 *Includes a 2.0 safety factor We recommend piles be driven such that the pile tip is located at the bottom of the stormwater vault elevation or deeper. We recommend that galvanized, steel pipe be utilized for the project.Two-inch diameter piles, consisting of schedule 80 pipe, are typically installed with a 90-pound jack hammer. Three- and 4-inch diameter pin piles, consisting of schedule 40 pipe, are typically installed using a hydraulic hammer attached to a small excavator. We recommend that the piles be driven to "refusal". Refusal is defined as one inch or less of penetration into the ground over a specified time interval (in seconds) of sustained driving. The time interval used to define refusal is based on the type of hydraulic hammer used. Refusal criteria time intervals for several hammer types typically used to install 2-, 3-, and 4-inch diameter pin piles are presented in the following table. Hammer Refusal Criteria Hammer Model Actual Hammer Hammer Foot- Refusal Criteria (seconds/inch) No. Weight(lbs.) Pound Class 2" dia. 3" dia. 4" dia. Jackhammer 90 - 60 - - TB 225 650 550 - 12 - TB 325 850 850 - 10 16 TB 425 1100 1100 - 6 10 TB 725 2000 2000 - - 4 13