岩石地区铁路嵌固桩设计

Design of Railway Embedded Piles in the Rock Areas

鲁南高速铁路临曲段、日临段由于基岩强度高、弱风化层基岩埋藏较浅而大量采用了嵌固桩。但岩石地区铁路嵌固桩设计案例较少,因此有必要对嵌固桩的设计进行深入研究,以确定本线嵌固桩基础的设计方法和原则。通过研究,总结了嵌固桩的计算方法,并得到以下结论:(1)嵌固桩必须检算基底应力;(2)嵌固桩主要由嵌固深度控制设计,高烈度地震区基底应力有可能会控制设计;桩基承载力、下部结构组合刚度、墩顶纵横向位移、桩身强度及桩侧土压力等检算均不控制设计;(3)进行嵌固深度计算时,对基岩的单轴抗压强度宜进行折减修正。

A lot of embedded piles are adopted because of high bedrock strength and shallow buried weak weathered layer in Lin-Qu section and Ri-Lin section of South Shandong high-speed railway. However,there are few design cases for the railway embedded piles in the rock areas,so it is necessary to study the design of the embedded pile to determine the design method and principle of embedded pile foundation of this line. The calculation method of the embedded piles is summarized by studying and the following conclusions are obtained：（ 1） The foundation stress should be checked for the embedded piles;（ 2） The embedded piles is mainly controlled by embedded depth calculation,and the design of foundation stress calculation in high earthquake intensity areas may be controlled,however,the design of calculation of the pile foundation bearing capacity, the composite stiffness of the lower structure, the vertical and horizontal displacement of the pier head,the strength of the pile body and the soil pressure at the side of the piles are not controlled.（ 3） When the embedded depth is calculated,the uniaxial compressive strength R of the bedrock should be corrected.