滑坡灾害过程耦合机制与方法研究

在三峡库区,沿江公路、城镇基础设施等所在区段,往往也是库岸再造、滑坡灾害多发地段。在基础设施修建过程中,有土石方开挖和填筑过程,期间还可能有不利的降雨过程、库水位浸泡过程、库水位降落过程、滑坡前缘冲蚀与淘蚀过程等等,这些过程耦合作用对滑坡稳定性有何影响,是滑坡工程评价和治理的关键。提出滑坡稳定性过程耦合机制及方法的新观念,并通过算例分析发现,对滑坡稳定性而言,水体入渗、前缘开挖、后缘填筑过程,均会降低滑坡稳定性。一般而言,水体入渗过程造成的滑带土抗剪强度参数衰减影响最显著,出现不利过程耦合时,对滑坡稳定性有灾难性影响。由于存在过程耦合作用的效果问题,因而在建设过程中应采取合理的施工步骤。

RESEARCH ON COUPLING MECHANISM AND METHOD OF LANDSLIDES DISASTER PROCESSES

In the Three Gorges Region,many infrastructures along Yangtze River bank are located on landslides.During the construction period of infrastructures,there exist earthwork excavating processes,filling process and raining process,marinating and hydrograph descent process by reservoir level change,etc..The effect of these processes and their coupling mechanism on landslide stability is a key problem to the stability evaluation and control of landslides.Conventionally,engineers usually regard these processes as loadings in landslide stability analysis.The new concept that engineers can evaluate landslide stability with processes coupling mechanism and method.With the analysis of an example,it shows that,to the stability of landslides,water penetrating process,excavating process at landslide foreside,and filling process at landslide tail have great effects on the stability of landslide;and the water penetrating process resulting in the attenuation of anti-shear strength parameters may affect the stability drastically.When these disaster progresses are coupled with each other,the effect on the stability of landslide is considerable.Because of the processes coupling effect,adequate construction steps should he adopted.