二维滑坡滑距预测

本文基于Kyoji Sassa滑坡运动模型的假设,即运动的滑坡满足牛顿流体运动方程,滑体内只存在侧压力,滑坡体积保持不变,能量损失只产生于滑面处的滑动摩擦,推导了二维滑坡运动模拟微分公式。将微分公式转化为差分公式,用Visual Basic语言编写出二维滑坡运动模拟程序。以陕西省延安市延炼原油山黄土滑坡为例,根据滑前地形,通过现场钻探揭示滑面,选择滑带土残剪试验测得的残余摩擦角作为视摩擦角,进行滑动模拟,结果与实际滑坡接近。最后以此滑动模型预测该滑坡南侧不稳定斜坡滑动的距离,对边坡滑动破坏后的危害范围做出预测。本文为滑坡滑距预测提供了一种简单、适用的方法。

PREDICTION OF LANDSLIDE TRAVEL DISTANCE WITH 2-D NEWTON FLUID DYNAMICS

This paper assumes the following four conditions. The movement of the landslide mass meets the requirements of Newton fluid dynamics equation. There is only lateral pressure inside the moving mass. The volume of the mass does not change. And all energy loss during motion is caused by friction in the motive model proposed by Sassa Kyoji. It derives the two dimensional movement formulas on the basis of the four assumptions. Meanwhile, the simulation program is compiled for the formulas. A case study is carried out. It is about Yanlian Yuanyoushan loess slow transitional landslide in Yanan City, Shaanxi Province. The geological model is set up by recoverying the topography before sliding and seeking out the slip surface by in-suit drilling. In the two-dimensional motive simulation, different residual friction angles are adopted as the sliding frictional angle. The results show that the run-out distance and the accumulation form are both very close to the in-situ measured results. Finally, the possible run-out distance of the critical slope on the left side of Yanlian yuanyoushan landslide is predicted with this movement model. And the potential hazards are also assessed. The result presented in this paper can provide a simple and applicable method of prediction for the sliding distance of landslides.