桩径对Mindlin附加应力系数的影响分析

基于Mindlin理论关于点荷载附加应力系数的解析解答,研究不同土体泊松比、桩长条件下桩径对Mindlin附加应力系数的影响规律,确定不同偏差标准下必须考虑桩径影响的最小范围,并给出需考虑桩径影响最小范围的拟合公式。研究结果表明,土体泊松比Mindlin附加应力系数总体影响较小,统一采用0.35土体泊松比引起附加应力计算偏差一般不超过5%;Midlin附加应力计算中,必须考虑桩径影响的最小范围主要与桩径相关,且随桩长的增加而增大;分别采用1%和5%误差标准时,必须考虑桩径影响的最小范围分别为桩径的13.6倍和6.41倍。

Research on Pile Radius Influence on the Coefficient of Mindlin Additive Stress

Based on the analytical solution of Mindlin theory for the additive stress calculation induced by point loading,relationship between pile radius and Mindlin additive stress coefficient is discussed in detail with different poisson ratio and pile length. Subsequently,the minimum influence range of pile radius under different error standard is determined,and the fitting equation of influence range is obtained accordingly. Research results indicate that the influence of the soil poisson ratio on the additive stress is at a very low level, and the greatest error is normally less then 5% if the poisson ratio value of0. 35 is applied. During the calculation of Mindlin additive stress coefficient,the minimum influencerange of pile radius is mainly determined by pile radius,and would keep increasing with the increasing of the pile length. Moreover,if error standards of 1% and 5% are accepted respectively,the minimum influence range of pile radius should be 13. 6 and 6. 41 times of the pile radius respectively.