摘要
滑坡推力计算一直是边坡防治核心问题。针对我国规范中传递系数法只适用于二维问题且滑移面形状只能为圆弧形或坡度不大的折线形问题,基于边坡体当前有限元应力状态,参考传递系数法的力学模型,推导加载型及强度储备型下滑推力计算公式,提出一种计算滑坡剩余下滑推力的有限元法。该方法考虑坡体下滑力的矢量特征,以局部潜在滑体为研究对象,通过应力矢量积分不仅能给出设计安全系数下坡体沿滑移面的下滑推力曲线和对应的下滑方向曲线,而且根据坡脚处下滑推力的迭代计算可得到坡体当前的稳定安全系数。典型算例计算结果表明:该方法与传递系数法得到的剩余下滑推力曲线规律一致,且通过下滑推力迭代得到的坡体安全系数与严格极限平衡法相比,精度均较高,计算误差在工程上完全可以接受。最后将该方法应用到西藏樟木典型折线形边坡体,两种方法得到的剩余下滑推力基本一致,验证了该方法计算下滑推力的合理性及工程应用可行性。
Calculation of landslide thrust is always a key problem in reinforcing design of slopes.Currently,there is an inconsistency issue existing in Chinese technical code for building slope engineering with regard to the thrust calculation using the transfer coefficient method,which is largely caused by the inaccurate assumption about the stress state of a slope.Aiming to overcome this issue,a new method considering the vector characteristics of sliding and anti-sliding forces was proposed and adopted to calculate the residual sliding force of a local potentially sliding body.Not only the sliding force but also the sliding direction of a potentially unstable slope can be evaluated by the proposed method.Several examples were illustrated and the calculated results of the safety factor of slopes were in good agreement with the rigorous limit equilibrium method.Finally,the proposed method was applied to analyze a typical fold line slope of Zhangmu town,in the Tibet of China,and the residual sliding force calculated by the proposed method also agrees well with the result from the transfer coefficient method.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第A02期4054-4065,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金面上项目(51674239
51379204)~~
关键词
边坡工程
下滑推力
有限单元法
矢量积分
传递系数法
安全系数
slope engineering
sliding force
finite element method
vector integral
transfer coefficient method
safety factor
