低围压下极限摩阻力对回填体基桩承载特性的影响

为了研究回填体极限摩阻力变化对基桩承载特性的影响,通过考虑低围压下回填体极限摩阻力的非线性变化,获得指数型荷载传递函数的回填体桩基Q–S曲线计算方法,对比现有研究成果与工程实例验证该计算方法,并探讨了极限摩阻力参数对桩承载特性的影响。分析结果表明:嵌岩段的桩侧摩阻力先达到极值,回填体的极限摩阻力随着桩侧法向应力?与回填体的试验参数A,b的增加而增加,提高桩侧摩阻力和桩基的极限承载力,法向应力?对桩侧摩阻力和桩的极限承载力影响很明显。

Influences of ultimate frictional resistance at low confining pressure on bearing characteristics of backfill piles

In order to study the influences of the ultimate frictional resistance of the backfill on the bearing characteristics of piles, the method for calculating Q-S curve of piles with exponential load transfer equation is obtained by considering the nonlinear change of the ultimate frictional resistance of backfill under low confining pressure. This method is validated by combining the existing research results and engineering practice results, and the influences of parameters of the ultimate frictional resistance on bearing characteristics of piles are discussed. The results show that the side resistance of the rock-socked section first reaches the extreme value. The normal stress σ and the test parameters A and b of the material are very beneficial to improve the side resistance and the ultimate bearing capacity of piles. Especially, the influences of the normal stress σ on the side resistance and the ultimate bearing capacity of piles are obvious.