基于有限元应力积分传递系数法的岩质边坡抗滑稳定分析

Analysis of anti-sliding stability of rock slope based on finite element stress integral transfer coefficient method

针对含非贯通软弱结构面的岩质边坡抗滑稳定问题,将有限元法与传递系数法结合,提出考虑主抗滑面位置搜索的有限元应力积分传递系数法。在弹塑性有限元法分析应力场的基础上,使用应力积分求得各滑裂面上的法向及切向力;在等安全系数条件下,模拟边坡失稳时剩余推力沿滑裂面依次传递到主抗滑面的过程并对各滑裂面建立极限平衡方程;最后结合Fortran语言快速搜索主抗滑面起点位置、倾角及对应的最小安全系数。通过算例分析发现:有限元应力积分传递系数法能精确找到主抗滑面的位置,并将边坡稳定性量化到一个具体的数值。克服了传递系数法只能进行刚性分析及需要假定主抗滑面位置的缺点,相比强度折减法也少了人为判定引起的误差问题,结果更合理可靠。

The finite element stress integral transfer coefficient method is proposed to solve the problem on anti-sliding stability of the rock slope with non-penetrating weak structural plane,which can search the position of main anti-slip surface by combining the finite element method with the transfer coefficient method.Based on the stress field analysis of elastic plastic finite element method, we obtain the normal direction and tangential force of each sliding surface using the stress integral.Under the condition of equal safety factor,we simulate the dynamic process of residual thrust transfer along the slip surface to the main anti-slip surface when the slope is unstable,and set up limit equilibrium equations of every slip surface.Finally,we search the starting point position and angle of the main anti-slip surface and the corresponding minimum safety factor using Fortran. The calculation example show that the finite element stress integral transfer coefficient method can accurately find the main anti-slip surface＇ s position,and the slope stability can be quantified to a specific value.This method overcomes the disadvantages of transfer coefficient method which can only analyze the rigidity and need assume the position of main anti-slip surface.In contrast to the strength reduction method,the error caused by human is also reduced.So the result is more reasonable and reliable.