基于连续块体理论的土石坝边坡破坏过程研究

A research for process of earth dam slope failure based on continuous block theory

由于年久失修、地质水文条件变化等因素导致的中小土石坝发生坝坡滑塌现象,严重危害附近区域人民生命财产安全,因此需要找到一种更加合理的方法来对可能引发滑坡事故的因素作出远期预测与灾害评估,以便作好相应补救措施。借鉴国外经验,将基于改良型能量守恒的连续块体理论应用到国内的土石坝滑坡中,对国外The Lower San Fernando大坝溃坝事故进行分析计算比较,验证该理论的合理性。将该理论应用于一个土石坝滑坡模型中,通过改变填土的土性参数与坝前水位构成不同工况组合,进而研究不同工况下土石坝边坡破坏过程与破坏机理。结果表明:在计算模拟条件下土石坝边坡稳定影响最大的因素为水位,土的c值影响其次,摩擦角φ值影响最小,三者中水位的影响具有决定性的作用。研究成果是采用基于能量的连续块体理论对土石坝滑坡机理的一种探讨,是对土石坝抗滑稳定计算方法的一种补充,对土石坝设计具有一定参考价值。

There are a considerable portion of the small earth dams due under disrepair,geological and hydrological conditions changed and other factors which make slope landslides occured frequently,affect the safety of life and property of the people of earth dam nearby area.Depending on the design method of stability specification used to control the stability of the dam is not enough,we also need to find a way to change in the future due to various factors that landslide accident will happen to long-term forecasting and disaster assessment in order to make the appropriate preparations.Basing on the modeling of landslide domestic computing research,using a calculation based on energy conservation to simulate a continuous block theory landslide.At first,the article describes the details of a continuous block theory based on the energy point of view,the theory is then applied to the actual model,since the simulation results are compared with the actual results to prove the theory and algorithm accuracy.Finally,the theory is applied to numerical simulation of an earth dam landslide instance,the nature and level by changing the filling of the dam constitutes a combination of different conditions,and thus the destruction of different process conditions and failure mechanism of earth dam slope.The result shows that the influence of water level is the most important factor affecting the slope stability of dam under the simulated conditions.The influence of soil c value is secondly,and the influence of friction angleφis the least.The research result is a discussion of the landslide mechanism of dam using the theory of continuous block based on energy,which is a complement to the calculation method of the stability of dam and has certain reference value for the design of dam.