单锚式钢板桩结构锚固位置影响分析

单锚式钢板桩结构锚固位置的变化对结构的体系性能有着显著影响,但目前设计及研究中对这一问题重视不够。首先采用自由支承法确定单锚式钢板桩结构体系设计方案;然后基于上述设计方案的有限元模型,同时考虑桩身及土体变形特性,研究锚固点位置对板桩弯矩、锚杆轴力及结构位移的影响规律。结果表明,锚固点位于钢板桩顶部以下0.25~0.3倍开挖深度时,钢板桩的最大水平位移和桩后土体的最大沉降达到最小值;随着锚固点位置由桩顶向下移动,锚杆的轴力逐渐增加,而板桩的最大弯矩逐渐减小。同时,与有限元结果相比,采用自由支承法所得到的结构体系的板桩弯矩偏大,有利于板桩的安全性,而锚杆的轴力偏小,可能导致锚杆的失效。

Influence of anchor location on single anchored sheet-pile structure

The change of the anchor location of single sheet-pile structure has a great influence on its structure system performance,however this problem is insufficiently considered in the current design and research.This paper consists of two parts.The first part is concerned with the design of the single sheet pile structure system using the free earth support method.On basis of the structure system design obtained in the first part,the second part applies the finite element method to investigate the effect of the anchor location on the wall bending moments,anchor forces and structure displacements where the sheet pile and the soil deformation characteristics are taken into account.The results show that,at the anchor point between the 0.25 and 0.3 times of the dredging depth,the maximum wall horizontal deformations and the ground settlements behind the wall reach the minimum value and as the anchor point moves down from the top of the pile,the anchor force increases and the maximum wall bending moment decreases.Furthermore,compared to one of FEM,the single sheet pile structure system of the free earth support method has the overestimating wall bending moments which are conducive to the safety of the wall pile and the underestimating anchor forces which lead to the failure of the anchor.