按单桩极限承载力设计复合桩基时的整体承载力安全系数

SAFETY FACTOR OF COMPOSITE PILE FOUNDATION DESIGNED BASED ON ULTIMATE BEARING CAPACITY OF SINGLE PILE

从复合桩基的桩、土共同作用的机理出发,对复合桩基的整体承载力安全系数作了较为完整的分析。考虑桩、土分担荷载之比和桩、土安全系数取值的影响,提出了用分项系数法对整体承载力安全系数进行定义,同时考虑了桩侧摩阻力和桩端阻力的大小及安全系数取值的影响。在计算复合桩基整体承载力安全系数时,考虑了由于遮拦作用而使土的极限承载力有所提高以及计入了群桩效应而使桩的极限承载力发生变化的情况,使得复合桩基整体承载力安全系数的定义和计算更加合理和完整。

Based on the mechanism of combined action of piles and soils in composite pile foundation,the safety factor of foundation is analyzed.By considering the influence of the load ratio and safety factors of piles and soils,the component factor method for defining the safety factor of total bearing capacity is presented.It’s suggested that the ultimate bearing capacity of soil will increase when the influence of caps is considered and the ultimate bearing capacity of pile will change because of pile group effect.So,the presented definition and calculation of the safety factors of foundation are more reasonable and integral than previous ones.