Large diameter rock-socketed piles have been extensively used in the foundation of platform and offshore engineering. Behavior of the large diameter rock-socketed CFST (concrete filled steel tube) piles under lateral loads is studied based on field tests and numerical analysis for piles for a port. The CFST piles are 2800 mm in diameter and 40m in length, with 5.2m socketed into the rock. The horizontal capacity and deformation of the large diameter rock-socketed piles is analyzed from the measured results of displacement and internal force of piles. The interactive behavior of pile-rock and the influence of backfilled sand on horizontal capacity are also discussed. Using FEM considering the properties of the pile-soil interface, the test results are simulated numerically and the design of a reasonable socketed length is studied.

INTRODUCTION

Large diameter rock-socketed piles have been extensively used in the foundation of platforms and offshore engineering in China (Zhang, 1995; Cao, 1999; Xu, 1999). Therefore increasing importance has been attached to the study of bearing capacity of large diameter rock-socketed piles under offshore conditions, especially the bearing capacity and deformation of subaqueous rock-socketed piles under lateral loads. Due to the complexity of offshore environment and construction workmanship, and large lateral loads on offshore platforms, the mechanism of subaqueous rock-socketed piles under lateral loads has become one of the major research interests in offshore engineering. Although there is much literature on lateral loaded rock-socketed piles (Simic, 1989; Hunter etal, 1992; Reese, 1997; Zhang etal, 2000; Ng etal, 2001; Nip etal, 2005), little research has been conducted into the behavior of large diameter rock-socketed piles, especially on the subaqueous rock-socketed concrete filled steel tube piles (CFST piles) under lateral loads. In this paper, the behavior of the large diameter rock-socketed CFST piles under lateral loads is studied based on field tests in the port of Majishan and numerical analysis.

Keywords:
lateral displacement, critical load, socketed length, load test, rock-socketed pile, weathered crystal tuff layer, foundation, diameter rock-socketed pile, backfilled sand, bearing capacity
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2007. The International Society of Offshore and Polar Engineers
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