不均匀软土路基稳定性与变形曲线特性分析

Analysis of Stability and Deformation Curve Characteristics of Uneven Soft Soil Subgrade

为进一步研究不均匀软土地基性能,基于武汉鄂咸高速公路软土路基施工项目,根据现场各类土体参数及位置沿路线变化较大的现象,建立二维不对称路基简化模型。研究在不对称土体参数变化作用下的边坡稳定及变形规律。结果表明,①不均匀弹性模量对安全系数的影响极小,边坡两侧填土水平位移最大值变化趋势整体呈相反态势,当左侧弹性模量小于对照组时,沉降增幅明显,当左侧弹性模量大于对照组时,沉降有一定程度缩减;②随着左侧黏聚力和内摩擦角的增加,各断面填土两侧水平位移均相应减小,安全系数增加,黏聚力与内摩擦角的最危险滑移面取决于边坡土体最弱处,两者在沉降曲线中有显著差异,在不均匀内摩擦角的作用下,断面两侧沉降趋势相反,同侧随内摩擦角缩小而沉降增加,异侧有小幅回升。

In order to further study the uneven soft soil subgrade,based on the construction project of the Wuhan-Exian Expressway soft soil subgrade and considering the significant variation of various soil parameters along the route,a two-dimensional asymmetric simplified model of the subgrade was established.The stability and deformation characteristics of the slope under the effects of asymmetric and uneven soil parameter variations were investigated.The results showed that:(1)The effect of uneven elastic modulus on the safety factor was minimal,and the extreme values of horizontal displacement of the filling on both sides of the slope showed a contrasting trend.When the elastic modulus on the left side was smaller than the reference group,the settlement increased significantly.When the elastic modulus on the left side was larger than the reference group,the settlement was reduced to some extent.(2)With the increase of cohesive force and internal friction angle on the left side,the extreme values of horizontal displacement of the filling on both sides of each section decreased correspondingly,and the safety factor increased.The most dangerous sliding surface determined by cohesive force and internal friction angle always depended on the weakest part of the slope soil,and there were significant differences between them in the settlement curve.Under the influence of uneven internal friction angle,the settlement tendencies on both sides of the section were opposite,with an increase in settlement on the same side as the decrease in internal friction angle,while the opposite side showed a slight rebound.