TILT: THE TREASURE ISLAND LIQUEFACTION TEST

This report presents the results of the Treasure Island Liquefaction Test (TILT), a joint project carried out by the University of California, San Diego, and Brigham Young University. To improve our understanding of the lateral load behavior of deep foundations in liquefied soil, a series of full-scale lateral load tests were performed at the National Geotechnical Experimentation Site (NGES) at Treasure Island in San Francisco, California. The ultimate goal of the TILT project was to develop lateral load-displacement relationships for a variety of individual piles and pile groups in liquefied sand under full-scale conditions. The tests were carried out using a high-speed hydraulic loading system after the sand surrounding the piles was liquefied using blasting techniques. This report presents backcalculated p-y curves for single pipe piles, pile groups, and cast-in-steel shell piles before and during liquefaction, as well as through dissipation of excess pore water pressures. In addition, recommendations with regard to design of deep foundations in liquefied soil are presented.