Settlement Control Meets Flood Control—Hybrid Compaction Grouted Ground Anchors for NYU Langone Medical Center’s Kimmel Pavilion

This paper discusses the innovative approach employed at NYU Langone Medical Center’s Kimmel Pavilion to address two natural hazards with a single grouted element system. Poor subsurface conditions necessitated the use ground improvement to address the potential for seismically induced settlement while ground anchors were needed to provide uplift resistance during coastal flooding conditions. These hazards were compounded by physical and legal restrictions imposed by rail and sewer infrastructure passing below the site. As originally envisioned, the design called for a performance based compaction grouted program followed by installation of passive ground anchors. Prior to commencing general construction activities, Moretrench American Company proposed an alternative hybrid anchor to accomplish both design tasks using a single element. The system proved highly effective for both uses during a trial program and a full production program was implemented. A detailed testing program was performed for the production elements and included pre- and post-treatment borings and CPT’s, analyses, and tensile load tests.