基于图表法的岩质斜坡永久位移快速计算方法

A Chart-based Method of Rapidly Calculating Permanent Displacement of Rock Slope

岩质斜坡地震稳定性的快速评价是学者们关注的热点和难点。传统上,大多数研究采用图表法得到的安全系数快速评价岩质斜坡的地震稳定性,目前缺乏快速计算岩质斜坡临界加速度的方法。如何构建临界加速度模型是计算斜坡永久位移的前提条件。为此,采用有限元极限分析方法(平均界解)和广义Hoek-Brown强度准则,提出了一种快速计算岩质斜坡临界加速度的新方法。对概化岩质斜坡进行数值建模,基于1 960次的案例计算结果,绘制了岩质斜坡临界加速度图,通过2次拟合统计分析,构建了岩质斜坡临界加速度与斜坡几何条件和强度参数的函数表达式,并将本文方法与Newmark模型和数值解进行了比较。结果表明,本文方法的计算精度比Newmark模型更接近数值解。所开发的岩质斜坡永久位移计算方法高效、便捷,不仅能够用于单体斜坡地震稳定性的快速计算,还可以为计算区域尺度内大量斜坡的永久位移提供技术支撑。

The rapid calculation of seismic stability of rock slopes remains a prominent and challenging focus among scholars.Historically,the chart method has been predominant in acquiring safety factors to swiftly evaluate the seismic stability of such slopes.However,approaches for promptly determining the critical acceleration of rock slopes are in lack.Establishing a model for critical acceleration is a prerequisite for computing the permanent displacement of slopes.To address this issue,we present a novel approach for swiftly computing the critical acceleration of rock slopes by employing the finite element limit analysis method( mean bound solution) and the generalized HoekBrown strength criterion.We obtained the diagram of critical acceleration based on 1 960 case calculations via numerical simulations for a generalized rock slope.Subsequent to two fitting statistical analyses,we derived a functional relationship between the critical acceleration of rock slopes and their geometric attributes and strength parameters.Comparisons of the results of the proposed method with those of the Newmark model and numerical solutions demonstrate that the computational accuracy of the proposed method aligns more closely with numerical solutions compared to the Newmark model.The developed method for calculating permanent displacement in rock slopes proves efficient and convenient.It not only facilitates the rapid assessment of seismic stability for individual slopes but also offers technical support for calculating permanent displacement across a large number of slopes on regional scale.