环境因素对路基沉降影响的分析

Analysis on the effect of environmental factors on subgrade settlement

在秦沈线的路基沉降观测过程中 ,发现在上部填土荷载恒定不变的情况下 ,不同区段、路基的不同平面位置上测得的沉降过程曲线 ,有的发生陡降 ,有的发生较大沉降后又产生回弹。在详细分析了沉降过程曲线、地下水位变化曲线等资料的基础上 ,发现上述异常现象是抽取地下水和冻融作用这两个环境因素所致 ,抽取地下水会引起沉降猛增 ,而冻融作用会使沉降发生往复变化。本文较为详细地阐述了这两个环境因素影响沉降过程的方式 ,并且就抽取地下水对沉降的影响作了一些量化的分析。

During the course of monitoring of subgrade settlement in Qinhuangdao Shenyang railway line construction, although the filling load keeps unchanged, it is discovered that some of the curves of settlement versus time from different sections of the line and different locations of the subgrade go down steeply, while some other rebound after going down. After detailed analysis of the curves of settlement versus time and curves of groundwater level versus time and some other data, the exceptional phenomena mentioned above is found. They are caused by two environmental factors: freezing thawing action and pumping groundwater. Pumping groundwater leads to the great increase of subgrade settlement and freezing thawing action leads to the to and fro change of subgrade settlement. The way that how two environmental factors act on the course of subgrade settlement is relatively detailed in this paper. Furthermore, some quantitative analyses on the effect of pumping groundwater on subgrade settlement are made.