冻土层对黄土地基水平受荷桩承载力影响研究

Influence of Frozen Soil on Pile Bearing Capacity under Lateral Loads in Loess Foundation

通过有限元数值模拟研究了季节冻土区冻土层对黄土地基水平受荷桩承载力的影响规律。研究表明:单桩水平承载力受冻土层厚度和桩径影响显著,随冻土层厚度的增大而增大,但增加的幅度减小;随桩径的增大而近似线性地增加,且冻土层厚度越大,随桩径增大的幅度越大。提出了基于变形控制的不同冻土层厚度、不同桩径水平受荷桩承载力特征值修正系数。基于计算结果进一步对修正系数进行拟合,得到了季节冻土区黄土地基水平受荷桩承载力特征值修正系数表达式,可供冬季检测单桩水平承载力参考。

With the finite element numerical simulation,rules of piles under the lateral load of the loess foundation affected by permafrost layer in seasonal frozen area are studied. Permafrost layer thickness and pile diameter have significant influence on the horizontal bearing capacity of single pile. Lateral bearing capacity of the single pile on the one hand increases with the increase of the thickness of permafrost layer,but the increasing amplitude decreases,on the other hand it approximately linearly increases with the increase of the pile diameter and the increase amplitude increases along with the larger thickness of permafrost. Lateral bearing capacity characteristic value correction factor is proposed for frozen soil of different thickness and different pile diameters. Furthermore,based on the calculation results,correction factor expression is obtained to revise the lateral bearing capacity characteristic value of the loess foundation in seasonal frozen area. It provides reference to test the horizontal bearing capacity of single pile in winter.