Manhattan West – North Tower
New York, NY
John Civetta and Sons
2015 to 2016
Drill and install 82 sixteen-inch diameter rock anchors with design load of 922.5 tons. Anchors consisted of three thread bars in one drilled hole with lengths of 63′ and 83′.
WHAT MADE THIS JOB COMPLEX
This project utilized the largest solid bar capacity anchors in the world installed inside rock trenches and from temporary platforms within tight areas during concurrent excavation. The rock had seams in some locations that continued to fill the hole, preventing installation of rock anchors.
HOW POSILLICO SOLVED IT
Posillico engineered temporary platforms, casing extensions to platform elevation, and spoils diverters to allow rig to drill at each location and reduce spoils. After several attempts to flush out the seam in the rock and grout the void, the hole was grouted and a casing and under reamer was advanced past the void to allow the bars and grout placement.