软土中大直径超长群桩位移的实用计算方法

A Practical Method of Calculating the Displacement of Large-Diameter and Ultra-long Pile Group in Soft Soil

从单桩m法入手,提出了软土中大直径超长群桩位移计算的方法。将单桩分析与承台以及群桩分析结合起来,考虑了底部转角、有效桩长的作用,以及大直径超长群桩受水平力转动所引起的弯曲和压缩的影响。利用Mat-lab软件,对所推得的公式进行编程,计算验证,讨论了不同桩距和不同桩径时的各种情况。将计算结果代回单桩公式中,可得桩身的位移和应力曲线,整个计算方法成为一个闭合循环的求解过程。以安徽省某长江大桥锚碇基础的群桩为例,选用实际数据进行分析计算,并与三维有限差分法的计算结果进行对比,发现该方法具有较高的实用价值。

Based on method M,a method of calculating the displacement of large-diameter and ultra-long pile group in soft soil is put forward.Analysis on single pile,cushion cap and pile group are associated by this new method.The turn angle of the cap,effective pile length,and the pile group compression and bending induced by horizontal force rotation are also taken into account by this method.A computer program for the method is developed in Matlab.The results of various factors,such as pile space and pile diameter,are discussed.The calculated values are substituted back in the single pile equation generated by method M to obtain the pile displacement curve and pile stress curve.The method is a closed cycling process.It is applied to the analysis on actual data of anchorage foundation pile group of a bridge crossing Yangtze River in Anhui Province.It is found by comparing the calculation results with results from finite difference method that the method is of high practical value.