基于土体HSS本构模型的堆载对邻近桩基的性状分析

Characteristic Analysis of Surcharge on Adjacent Pile Foundation Based on Soil HSS Constitutive Model

软土地层中,桩基会因堆载而产生侧向位移和桩身的附加弯矩,这对桩基上部结构的稳定性产生不利的影响。为此,基于土体HSS本构模型,分析了不同约束条件下,地面堆载荷载大小与其作用位置、桩身及土体材料对邻近桩基的影响性状以及影响规律。数值模拟表明:桩基最大水平变形和弯矩随堆载的增大或荷载至被动桩距离的减小而增大,且桩身最大变形位置从桩身中部逐渐向桩顶过渡;桩顶会因顶部约束而产生较大的负弯矩从而抑制桩身侧向位移;嵌固深度对桩身弯矩无显著影响。

The lateral displacement of pile foundation and additional bending moment of pile body will be produced due to sur⁃charge action in soft soil stratum,which will have adverse effects on the superstructure of pile foundation.In order to analyze the in⁃fluence of the magnitude and position of surcharge load on the adjacent pile foundation,the material properties of pile body and soil,and the restriction conditions of pile body on the adjacent pile foundation,the method based on HSS constitutive model of soil is studied in this paper.The results show that the pile foundation will be greatly affected by the different loading position and soil condi⁃tion.The following conclusions can be obtained by numerical simulation that the maximum horizontal deformation and moment of pile foundation will increase with the increase of surcharge size or the decrease of the distance from load to passive pile,and the maxi⁃mum deformation position of pile body will gradually transit from the middle of pile body to the top of pile.The pile top will produce a large negative bending moment due to the top constraint to inhibit the lateral displacement of the pile body.The embedded depth is not the main influence of the moment of pile body.