实测表明,超长桩基础的桩身压缩量占总沉降量很大比例,因此,等代墩基法刚性体的假定不符合实际,需要一种考虑桩身压缩量的方法来计算超长桩基础沉降。通过对现有超长桩实测数据的分析,得到了嵌岩桩桩身压缩系数拟合方程,同时得出了非嵌岩桩桩身压缩系数约为0.5;推出桩侧沉降比和桩端沉降比,并编制了Matlab计算程序。最后通过工程实例计算考虑桩身压缩的超长桩基础沉降,计算结果与实测结果相吻合。
It's found that the compression of pile shares a high proportion of the overall settlement in overlength pile foundation.Assuming the pile foundation as a rigid body in the equivalent pier method is not appropriate.A method considering compressibility of pile is proposed to calculate the settlement of super-long pile foundation.By analyzing the existing test data of overlength piles,a fitting equation expressed by compressibility coefficient of rock-socketed pile shaft is given;and a coefficient of 0.5 for non-rock-socketed pile is obtained.The formulas for settling ratios of pile shaft and pile tip are deduced.Meanwhile,the Matlab program is realized.At last,considering compressibility of pile,a case study is presented to calculate the settlement of overlength pile foundation;and the calculated and measured results have good agreement.