黄土高填方边坡的稳定性影响因素及其变形规律

根据西北某路段黄土高填方边坡工程项目,运用 PLAXIS 3D 软件建立多级高填方边坡三维有限元模型,研究了填料、填土边界、坡度以及卸载平台的改变对边坡稳定性的影响.并根据边坡在分步填筑情况下各级边坡坡顶、坡面、坡脚的竖向位移及水平位移,分析了各级边坡最危险点的分布规律及整体边坡变形趋势.结果表明:填料黏聚力、内摩擦角是影响高填方边坡稳定性的关键性因素.降低填土与原状土体边界处台阶高度、加深台阶宽度、降低坡度以及加宽卸载平台,均可提高边坡的稳定性.较低处边坡施工期间竖向位移突变大,水平位移突变较缓慢;施工完成后变形情况均良好.较高处边坡施工期间竖向、水平位移突变大,分布不均匀;施工完成后固结沉降时期长,变形量大;需在施工完成后着重加强高处的变形监测.研究结果确定了西北地区黄土高填方边坡的稳定性影响因素、变形趋势及发展规律,为进一步研究黄土高填土边坡的变形控制提供了科学依据.

Stability factors and deformation law of loess high fill slope

Based on the loess high fill slope project in a certain section of Northwest China, this paper uses PLAXIS 3D software to establish a three-dimensional finite element model of the multistage high fill slope. The effects of changing fill, fill boundary, slope and unloading platform on slope stability were studied. According to the vertical displacement and horizontal displacement of the slope top, slope and foot, the distribution law of the most dangerous points at all levels and the trend of the whole slope deformation are analyzed. The results show that the cohesive force and internal friction angle of filling are the key factors affecting the stability of high fill slopes. Reducing the height of the step at the boundary between the fill and the undisturbed soil, deepening the step width, reducing the slope, and widening the unloading platform can improve the stability of the slope. During the construction of the lower slope, the vertical displacement changes rapidly and horizontal displacement changes slowly. The deformation is good after the construction. During the construction of the higher slope, the vertical and horizontal displacement abrupt change rapidly, and the distribution is not uniform. The consolidation settlement period is long and the deformation amount is large after the construction. It is necessary to strengthen the deformation monitoring of the higher slope after the construction. The research results determine the influence factors of stability, deformation trend and development law of loess high fill slope in Northwest China, and provides a scientific basis for further research on controlling the deformation of loess high fill slope.