砂黄土塔基边坡破坏机理研究

以陕北定边县砂黄土塔基边坡为研究对象,通过室内试验手段研究了砂黄土的物理力学特性,并与西安粘黄土的物理力学性质进行了对比。在此基础上,借助有限元软件MIDAS模拟不同工况下塔基边坡的应力应变特征,进而揭示了砂黄土地区塔基边坡的破坏机理。结果表明:砂黄土的天然密度与干密度较低,孔隙比较高,粗粉粒含量较多,摩擦强度明显较大,粘聚力较小;有限元模拟表明,随着影响因素的增加,坡肩拉应力不断增加,坡脚剪应力不断集中,边坡稳定性逐渐减小,最终形成潜在滑动面并发生破坏,其中风荷载和降雨是影响边坡稳定性和应力应变的主要因素。

Study on Failure Mechanism of Sand-Soil Loess Tower Foundation Slope

Taking the sand-soil tower foundation slope of Dingbian County in northern Shaanxi as the research object,the physical and mechanical properties of sand loess were studied by means of laboratory tests,and compared with the physical and mechanical properties of Xi''an sticky loess. On this basis,the finite element software MIDAS was used to simulate the stress-strain characteristics of the tower foundation slope under different working conditions,and the failure mechanism of the towe foundation slope in the sand loess area is revealed. The results show that the natural density and dry density of sand loess are lower,the pores are higher,the coarse silt content is more,the friction strength is obviously larger,and the cohesive force is smaller. The finite element simulation shows that with the increase of influencing factors,the tensile stress of the slope shoulder increases continuously,the shear stress of the slope foot is continuously concentrated,the stability of the slope is gradually reduced,and the potential sliding surface is finally formed and destroyed,wherein the wind load and rainfall is are major factors affecting slope stability and stress strain.