1.China Electric Power Research Institute,Beijing;2.School of Engineering and Technology,China University of Geosciences,Beijing
It is an important issue to investigate the characteristics of end-bearing capacity and to determine the end-bearing resistance factor for the application of rock-socketed piles. In this study, the results of 165 compression load tests were collected to examine several issues related to the end-bearing capacity behavior of rock-socket piles. All these load test results were conducted on different rocks with different rock-socket piled conditions by different authors worldwide. Using these load test data, the type and the uniaxial compressive strength of rock in nature, the diameter and the embedment depth of socketed piles, the ultimate end-bearing resistances were compiled. The ratio of ultimate end-bearing capacity to unconfined compressive strength of the rock was defined as the end-bearing resistance factor of rock-socketed piles. Effects of the pile diameter, the pile depth rocked into rock, the ratio of rocketed depth to diameter, and the unconfined compressive strength of the rock on the ultimate end-bearing capacity and the end-bearing resistance factor were comprehensively investigated. An empirical relation between the unconfined compressive strength and the end-bearing capacity as well as the end-bearing resistance factor were suggested, which could be used in the design for rock-socketed piles.