刚性嵌岩桩单桩刚度系数推导

Deduction of single pile stiffness coefficient of rigid rock socketed pile

群桩基础单桩内力计算,最重要的一环是先求得各单桩刚度系数,在桥梁基础中,弹性桩较为普遍,其单桩刚度系数根据规范易得,而实际工程中,会遇到桥址处为岩石地质,而且基岩面起伏比较大的情况,这时就会出现刚性嵌岩桩,如何求解刚性嵌岩桩刚度系数十分关键。根据刚性嵌岩桩的特性,不计桩侧土压力对桩身产生的侧移,运用结构力学及材料力学相关知识推导刚性嵌岩桩的单桩刚度系数,并与规范提供的刚度计算方法进行对比,以此说明公式适用范围。解决了包含刚性嵌岩桩的群桩基础的单桩内力计算问题。

The most critical step in computing the internal force of an individual pile among the pile group is to obtain the stiffness coefficient of each pile.Elastic pile is a very common type of foundation for bridge structures its stiffness coefficient can be easily obtained according to Code.However,in some practical cases,the bridge is located in rocky area and the bedrock surface varies significantly.Under these circumstances,the piles are rigid and embedded in the bedrock.Calculation of its stiffness coefficient will be a crucial step.Based on the assumption that the soil pressure has no effect on the lateral displacement of the pile,the stiffness coefficient can be derived using structural mechanics.The results are compared with those obtained from bridge design specifications to illustrate the application scope of the proposed approach.Finally,the force of individual pile among a rigidsocketed pile group can be determined through this method.