铁路路基垫层厚度对CFG桩及下穿公路桥梁桩基的影响研究

Research on Influence of Thickness of Railway Subgrade Cushion on CFG Pile and underneath Passing Highway Bridge Pile Foundation

以西南地区某新建铁路下穿既有高速公路桥梁为例,运用有限元数值软件,以垫层厚度为变量,分析在路基填筑施工和安全运营两个阶段下的垫层厚度对CFG桩和既有桥梁桩基的力学特性影响。研究发现:CFG桩和桥梁桩基的沉降量随着垫层厚度的增加而减小,当垫层厚度为0.4 m时,桥梁桩基的沉降量变化速率出现拐点;桥梁桩基的最大竖向应力随着垫层厚度的增加而增大,当垫层厚度为0.4 m时,桥梁桩基的最大竖向应力变化速率出现拐点。

In this paper,taking a new railway in the southwest region underneath passing an existing highway bridge as an example,based on the finite element numerical software,with the thickness of the cushion as a variable,under the two stages of roadbed filling construction and safe operation,the influence of the mechanical properties of the thickness of the cushion on CFG piles and the existing bridge pile foundations is analyzed.The research found that the settlement of CFG piles and bridge pile foundations decreased with the increase of the thickness of the cushion.When the thickness of the cushion was 0.4 m,the rate of change in the settlement of the bridge pile foundation appeared an inflection point;the maximum vertical stress of the bridge pile foundation increases with the thickness of the cushion.When the thickness of the cushion was 0.4 m,an inflection point for the rate of change of the maximum vertical stress of the bridge pile foundation appeared.