边坡层状岩体三维横观各向同性数值分析

Three-Dimensional Transversely Isotropic Numerical Analysis of Stratified Rock Slope

建立层状岩体的三维横观各向同性连续介质力学模型,把三维Hoffman强度准则引入到层状边坡稳定性分析中,模拟不同岩层倾角下三维边坡破坏模式。结果表明:岩层为水平分布,剪应力起主导作用,易发生以剪切为主的损伤破坏;岩层为竖直分布,主应力起主导作用,易发生以拉应力为主的倾倒破坏;当层状岩体的走向与坡面走向一致,岩层倾角在0°～90°变化时,岩体从剪应力为主的破坏到拉剪组合破坏再到以拉应力为主的破坏过渡。另外,顺倾岩层的边坡更容易发生剪切滑移型破坏,而反倾岩层的边坡整体不易发生剪切滑移破坏,多存在局部小范围损伤,整体相对较稳定。研究结果可为层状岩体边坡的设计、支护和监测提供借鉴意义。

A three-dimensional continuum mechanics model for layered rock mass was established, and the 3D Hoff- man strength criterion was introduced into stratified rock slope stability analysis. The 3D slope failure modes in different an- gles were simulated. The results show that when the discontinuities are horizontally distributed, shear stress acts as the lead- ing role and leads to shear failure. When the discontinuities are vertically distributed, principal stress plays the leading role and leads to tilting failure because of the tensile stress. The failure mode acts from shear failure caused mainly by shear stress to tensile-shear stress caused by tensile-shear stress, and then to tensile failure caused mainly by tensile stress, when the strike of the strata is the same as the strike of the slope, and strata angle changes from 0° to 90°. In addition, shear and slip failure will occur more easily of the dip layered rock masses, but it will occur more hardly of the anti-dip layered rock slope that may have some small range damage but is overall stability. These research results can provide references for transverse isotropic slope design, support and monitoring.