桩端硬持力层冲切安全性评价及在红层中的运用

针对嵌岩桩桩端硬持力层厚度小于3d的实际情况，为确保安全又节省造价，在分析桩一岩土体系的荷载传递机理和岩石破坏模式的基础上，建立桩端硬持力层的冲切承载力计算公式，用该公式计算桩端硬持力层厚度的冲切承载力，并与桩基设计荷载相除得到安全系数K，根据安全系数K的大小判定桩端硬持力层的厚度能否满足荷载要求。工程实例表明，该方法在红层地区的运用效果好，可供借鉴。

Punching-cutting Safety Evaluation in the Pile Tip Hard-bearing and Application in the Red Beds

For hard rock-socketed pile tip bearing layer thickness less than 3 times actually, in order to ensure safe and cost savings, base on the analysis of pile-rock and soil system load transfer mechanism and failure mode of rock, we establish the punching capacity formula of pile tip hard-bearing stratum, then use the formula to calculate pile-end hard-bearing stratum anticutting capacity,and it was divided by the pile design load to obtain the of safety K, using the safety factor K to determine whether pile bearing stratum thickness can meet the load requirements. Project examples show： the method in the apply of the red layer region is good and reference.