基于强度折减法与可靠度方法的锚框支护边坡稳定性分析

以漳州招银高速公路典型锚框支护边坡工程为背景,在FLAC3D数值平台上,基于有限元强度折减法求得其稳定性安全系数为1.514,满足相关规范要求。进一步地考虑岩土体参数的变异性,根据多个类似工程的地质勘察资料,统计了相关岩土体抗剪强度参数的均值和变异系数。同时定义了该锚框支护边坡的极限状态和功能函数,并利用响应面法将其拟合为具有显式表达的非完全二次多项式。最后利用JC法,经过若干次迭代求得该锚框支护边坡的可靠指标为2.035 9,其失效概率为2.09%。将有限元强度折减法与可靠度方法相结合,可较全面地反映岩土体参数变异性对边坡稳定性的影响。

Stability Analysis of Anchor-frame Supported Slope Based on Strength Reduction and Reliability Methods

Taking the typical anchor-frame supporting engineering for the slope along Zhangzhou Zhaoyin Highway as the background, the stability safety factor thereof was solved to be 1.514 on FLAC3D numerical platform and by FEM strength reduction method, which may meet the requirement in the related specifications. With the variability of geotechnical parameters taken into consideration further, the mean value and variation coefficient of the shear strength were counted up according to the geological prospecting materials of similar projects. Moreover, this paper defined the limit state and performance function of this anchor-frame supported slope, and then fitted it as a non-complete quadratic polynomial with explicit expression by use of response surface method. Finally, the reliability index of the slope was solved by JC method to be 2.0359 through several iterations with the failure probability of 2.09 %. Combined with FEM strength reduction method and reliability method, the impact of geotechnical parameter’s variability on slope stability may be reflected comprehensively.