Abstract

Conventional landslide analyses, based on deterministic methods or simple random variable methods, cannot consider the spatial variability and the depth-dependent nature of saturated hydraulic conductivity (K_s) in accumulative landslides. However, studies show that these conditions exist objectively and have a large impact on the seepage and deformation of landslides. Thus, the non-stationary characteristics of K_s need to be properly accounted for. In this paper, the Baishuihe landslide is taken as a case study. First, based on surface nuclear magnetic resonance (surface-NMR) technology, spatial variability and the depth-dependent nature of the K_s are obtained. Then, a non-stationary random field model is established to model the trend and fluctuating components of the K_s individually, and a deterministic model is established to model the trend of the K_s with depth. Finally, numerical simulations of the stochastic model and deterministic model under reservoir water fluctuation conditions are carried out by the non-intrusive stochastic finite element method, and the seepage-deformation and stability characteristics of the landslide are analyzed. The results show that compared with that in the deterministic model, the change in pore pressure in the stochastic model obviously lags, during reservoir water drawdown, the displacement of the trailing edge in the stochastic model is larger than that in the deterministic model, with increasing reservoir water deceleration, the hysteresis of the pore pressure in the stochastic model is more notable, and the deformation is larger and the stability is worse in the stochastic model. It is demonstrated that ignoring the spatial variability of the K_s will overestimate the stability of the landslide.

中文翻译：

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具有非平稳特性的空间可变饱和导水率对储层滑坡稳定性的影响

摘要

基于确定性方法或简单随机变量方法的常规滑坡分析无法考虑累积滑坡的空间变异性和饱和导水率（K _s）的深度相关性。但是，研究表明，这些条件是客观存在的，并且对滑坡的渗流和变形影响很大。因此，需要适当考虑K _s的非平稳特性。本文以白水河滑坡为例。首先，基于表面核磁共振（surface-NMR）技术，K _s的空间变异性和深度相关性质获得。然后，非平稳随机场模型建立模型的第k趋势和波动分量_小号独立，并建立一个确定的模型到模型的第k趋势_小号与深度。最后，采用非侵入式随机有限元方法对水库水位波动条件下的随机模型和确定性模型进行了数值模拟，分析了滑坡的渗流变形和稳定性特征。结果表明，与确定性模型相比，随机模型中的孔隙压力变化明显滞后，在储层水位下降过程中，随机模型中后缘的位移大于确定性模型中的后缘位移，且随确定性的增加而增加。储层水减速时，随机模型中孔隙压力的滞后现象更为明显，在随机模型中变形较大，稳定性较差。证明了忽略K的空间变异性_s将高估滑坡的稳定性。