Abstract：Based on the data of static load test and results of ANSYS analysis，the bearing behavior of large-diameter and extra-long rock-socketed piles are studied. The settlement，the optimized rock socket depth，the distribution of side friction resistance and end resistance are mainly discussed. The results indicate (1) large-diameter and extra-long rock-socketed piles are generally end load friction piles，however，their end resistances cannot be neglected yet；(2) in the socketed section，the distribution of side friction resistance has obvious nonlinear characteristics，which are small at middle and big at both ends；(3) it is not effective to control pile head settlement only by increasing socket depth，and the rock socket depth can not be limited to the norms，which is less than five times of pile diameter. Therefore，some proposals are given to the design of piles.
