December 4, 2019 ITS Money: Tasos Papathanasiou, P.E.

Tasos Papathanasiou, P.E. | Langan Engineering and Environmental Services, Inc.

Performance of Various Pile Types in Sections of Brooklyn, NY Based on Load Test Results

Over the last few years there is an increased demand for 30+ story buildings in areas of Brooklyn, NY, where low-rise construction is prevalent. When high column loads cannot be accommodated by shallow foundations, a common foundation solution is friction piles. The presentation discusses pile design considerations and load test results for both driven and drilled friction piles in two projects. Comparisons and conclusions are drawn regarding the efficiency and capacity of each pile type and the important role of local geology in the design and installation of each system.

Findings

• Local Geology cannot be ignored during the design.
• A carefully designed pile testing program is essential to define pile capacity. 
• HSDT can underestimate the pile capacity in medium-dense sands, and delay between installation and testing of driven piles is essential for set-up.
• Pile installation must be performed by experienced and qualified contractors; installation means and methods affect the final pile capacity.