To accommodate for a new, heavier shiploader, the existing Pier G wharf in Port of Long Beach, California had to be upgraded to increase speed and capacity The design called for a moment resisting space frame to be constructed within the existing wharf footprint, yet independent of the existing structure.
Geosyntec's Scope of Services
Geosyntec provided geotechnical services that included replacing an outdated ship loader with a new, high-capacity loading system. Geosyntec planned and conducted the field exploration program, evaluated the capacity of the existing pre-stressed concrete pile system, and designed a new pile system that will partially support the new ship loader. The field exploration program consisted of mud-rotary drilling and Cone Penetration Test (CPT) sounding that reached depths of up to 100 ft. below the existing pier deck. Geosyntec conducted drilling and CPT testing in approximately 30 ft. deep sea water and through rip-rap at the mudline and evaluated vertical and lateral capacity of the existing pile group. We performed drilling and CPT testing from an elevated pier deck requiring concrete coring and the use of steel casing above the mud line.
Geosyntec developed and implemented a test pile driving program and provided Construction Quality Assurance (CQA) services during both test and production pile driving activities. We constructed the space frame by connecting two rows of 90-ft long, 24-in. diameter piles connected by orthogonal grade beams. The 200-ton capacity pre-stressed concrete piles were used at the ocean side of the project, while the 275-ton straight-wedge steel piles were used at the land side. Due to the space constraints, both the land and ocean side piles were driven from a barge. Geosyntec performed evaluation of pile driving records for 6 test piles using the GRLWEAPTM wave equation computer program, reviewed contractor submittals, developed pile driving criteria for 112 production piles, continuously supervised production pile driving, monitored pile driving-induced vibrations, settlement and associated damage to the asphalt paving, and performed spatial evaluation of the achieved pile capacities. We documented the results in a comprehensive CQA report.
Geosyntec innovatively designed the new pile system for stringent differential settlement tolerances and gave special consideration to the evaluation of pile capacity under seismic loading conditions, including the impact of soil liquefaction liquefaction-induced lateral spreading on piles.