Calculation Method of Socketed Length of Rock Socketed Pile Based on Requirement of Pile Top Settlement

Loading transfer mechanism of rock-socketed pile was deeply discussed.In view of the existing deficiency of the calculation method used in current standard for socketed length of rock-socketed pile,the load transfer equation was established according to the bearing mechanism of rock-socketed pile,the calculation method of the socketed length of rock-socketed pile was obtained based on the vertical load transfer characteristics of pile,and the expressions of pile tip load-sharing ratio and rock-socketed length were obtained.Finally,the variational behaviors of rock-socketed length and pile tip load-sharing ratio with pile top settlement were studied based on an engineering example.The results indicate that under the same conditions,(1) the smaller the requirement of pile top settlement is,the greater the required rock-socketed length is;(2) the greater the settlement is,the greater the bearing contribution of pile tip is;(3) the pile tip load-sharing ratio decreases with the increase of rock-socketed proportion.This method takes into account the settlement requirements of upper structure as well as the load-sharing ratio of pile tip,so the rock-socket length can be determined comprehensively from safety and economic aspects.