黄土高速铁路路基帮宽结构沉降变形模型试验分析

Model Test on Settlement and Deformation Mechanism of Broad Structure of Subgrade Side of High-speed Railway in Loess Area

在我国西北黄土地区铁路快速发展的背景下,为确保既有高速铁路帮宽结构的安全和正常服役,以黄土地区高速铁路帮宽路基结构为研究对象,荷载传递特性与沉降变形为核心,采用室内模型试验等方法,选取常规路基帮宽结构和加土工格栅路基帮宽结构,研究帮宽路基对既有路基结构荷载的传递特征,对比分析荷载作用下既有与新建路基的应力和沉降变形演变规律,揭示路基不均匀沉降变形响应规律。结果表明:既有路基铺设土工格栅,可以减缓路基下部地基和路基顶面的差异沉降,同时可以对路基内部应力起到扩散作用,可以增加该位置处的土拱效应,对高速铁路帮宽路基施工具有重要的指导意义。

Under the background of rapid development of railway in loess region of northwest China,in order to ensure the safety and normal service of the existing high speed railway subgrade widen structure,taking the subgrade widen structure of high-speed railway in loess area as the research object,load transfer characteristics and settlement deformation are the core,using indoor model tests and other methods,the conventional widened subgrade and the widened subgrade with the geogrid are selected.The load transfer characteristics of the widened subgrade transferring to the existing subgrade structure are studied,the evolution law of stress and settlement deformation of existing and newly built subgrades under load is compared.Deformation response law shows uneven settlement of subgrade.The results show that the application of geogrid in the existing subgrade can slow down the differential settlement between the subgrade bottom foundation and the subgrade top surface,and can play a role in the diffusion of the stress in the subgrade,and can increase the soil arch effect at this position,which has an important guiding significance for the construction of widened subgrade of high-speed railway.