Risk Analysis Of Stability Of Highway Bank Slopes

With the rapid development of the economic and the progress of the society, the high-grade road construction in the mountain area has gotten great and swift improvement. Nevertheless, it brings a great deal of geological hazard unavoidably, especially in the road construction along the riverside and lakeside or in the reservoir areas. On the effect of water, the geological hazards happen much frequently and even destroy the highway so that it causes great casualties and economic loss. Therefore, people become more and more aware of the importance of taking precautions to protect or lessen this kind of calamity, and, urgently, need to seek some effective control methods and means. Meanwhile, the necessary researches about the dangerous assessment and risk analysis on the geological hazard control became the effective methods in much favour. However, the highway, railway and the big and long petroleum pipeline projects all belong to the large-scale linear projects, which have the characteristics of wide trans-region, and have small-appraised space. Therefore, seeking the effective risk analysis theory and method becomes the key to appraise and control hazard effectively. This paper takes this kind of linear project of the Yu-Ba highway bank slopes in the reservoir areas of Three Gorges as an example, and has beneficial discussion toward this field. The main achievements the author has gotten are as following:(1)After analyzing and studying the types of lithological combination, the rock body structure, and the structure of bank slope, this paper has shown a set of basic geological modes, which are suitable for the stability appraisal of Yu-Ba highway bank slope in the reservoir area of Three Gorges, according to the local area characteristics. In addition, it has also analyzed the prospective deformation and destruction mechanism of bank slope.(2)This paper discussed the change of groundwater level with the reservoir water level fluctuation and rainfall preliminarily. According to certain assumed conditions and utilizing the Laplace vary, the author deduced the calculate formula of the soakage line (one-dimensional formula) in soil property bank slope and utilized 3D-Modflow procedure to check analysis. As we know, the reservoir water level will be up and down, and the rainfall may cause the fluctuation of groundwater table. Therefore, the landslide stability, in fact, is just a dynamic change course. In view of the above, the author put forward the concept of "Dynamic stability of landslide ", and put it into application onto the instance slope. At the same time, it has offered an effective means to choose a better therapy programme.(3)Considering the effect of the damp and hot climate in the reservoir area of Three Gorges, and the impact caused by 30 meter's drop when annual water level regulating after the storage is finished, the author, through expert's consultation and analysis about instance bank slopes, revised the hierarchical system HSMR of rock slope stability of the highway. Base on this, the author put forward the hierarchical system HBSMR of stability of the highway bank slope (Highway Bank Slope Mass Rating) and advanced further the synthetically influences coefficient of the groundwater which offered the facility...