旋喷桩空间布置对桩板墙变形控制效果研究

Study on Control Effect to the Deformation of Sheet Pile Wall used by Different Spatial Arrangements of Jet Grouting Pile

在松软土、黄土等埋深较厚的地区,桩板墙嵌固段的水平承载力不仅要受桩截面尺寸、桩间距及嵌固段桩长等因素制约,更受制于桩体嵌固段地层的地基系数大小.通常在软弱地基广泛分布的区域,单纯依靠增加桩截面或增加桩长,对控制桩板墙水平变形效果并不理想,采用旋喷桩加固桩前地基以显著提高其侧向抗力,对有效抑制桩身水平变形具有重要意义.本文通过FLAC3D建立三维数值仿真模型,针对蒙华煤运通道新建三门峡车站桩板墙试验段工况,研究了桩前地基在旋喷桩不同加固深度及不同平面布置间距条件下,桩板墙桩身弯矩及桩顶水平位移的变化规律及敏感性,在分析地基加固作用机理的基础上,进一步探讨了旋喷桩加固桩板墙墙前地基的合理布置深度及桩间距,为松软土地区桩板墙嵌固段地基加固设计与施工提供科学参考依据.

In the soft soil,loess and other thicker areas,the horizontal bearing capacity of the sheet pile wall is not only subject to section size of the pile,pile spacing and embedded section pile length,but also by the size of the foundation coefficient of the pile embedded section stratum.Usually in the area where the weak foundation is widely distributed,it is not ideal to rely on that the increasing pile section or pile length have horizontal deformation effect on the control pile wall.The pile foundation is strengthened by the jet grouting pile to significantly improve its lateral resistance,and the horizontal deformation of pile is of great significance.This paper establishes a three-dimensional numerical simulation model through FLAC3 D.According to the test section of the sheet pile wall of Sanmenxia station in Menghua coal transportation channel,the variation law and sensitivity of the sheet pile wall bending moment and horizontal displacement of pile top are studied under the condition of the different depth of the jet grouting pile and the spacing between the different plane layouts.Based on the analysis of the mechanism of foundation reinforcement,the reasonable layout depth and pile spacing of the pile foundation strengthened by the jet grouting pile are studied,which provides scientific reference for the design and construction of the embedded foundation of piled slab in soft soil area.