Study On The Safety Evaluation System Of High-Steep Cutting Slope And Application Along Railway In Southwest Mountain Area

With the rapid development of the national economy and the strengthening of transport infrastructure construction, the construction of high-speed railway has become an important part of the recent construction. There are high-speed railways,which will be built or are under construction in the southwest mountain area, such as Guizhou-Guangzhou Railway, Chengdu-Chongqing Railway,Lanzhou-Chongqing Railway, Chengdu-Guizhou Railway, Chengdu-Xi’an Railway, etc. A lot of high-steep cutting slopes being formed along the railway as the needs of construction broke the gneiss original geology environment balance. Under the impact of environment and project, it is easy to cause geological disasters, such as slope instability and collapsing, which will greatly endanger railway infrastructure and the transport safety. Therefore, it is necessary for studying the safety evaluation method of high-steep cutting slope of the high-speed railway in the southwest mountain area, which provide a basis for the construction and the transport safety.This thesis mainly based on the important research project of MOR Monitoring And Warming System Of The High-Steep Slope Safety (2010G018-E-4) makes a systemic research on the safety evaluation method of high-steep cutting slope along high-speed railway in the southwest mountain area by surveying actual geology data of related railways (Guizhou-Guangzhou Railway, Lanzhou-Chongqing Railway, ChengDu-MianYang-LeShan Railway), contrasting the slope safety evaluation methods, studying the factors influencing slope stability, and determining main controlling factors and the weight affecting slope stability. The main results obtained are as follows:1. The existing safety evaluation methods can be roughly classified into three categories: qualitative analysis, quantitative analysis, and uncertainty analysis. The advantages and disadvantages of the three methods have been analyzed comparatively. The uncertain methods of the slope stability evaluation based on Rough Set and Support Vector Machine enjoys unique advantages in solving the problems of fuzzy and uncertain factors affecting railway slope stability.2. By way of field investigation and data analysis scientifically, the tri-grade evaluation index system of the soil and rock slope safety evaluation method is established separately, providing a basis for analyzing the main factors of the safety evaluation method.3. The main factors of the soil and rock slope safety evaluation method are obtained through reducing the factors influencing slope stability by attribution reduction of Rough Set. Research has shown the factors influencing slope stability can be reflected by the main controlling factors of the safety evaluation which makes a good foundation for establishing railway slope evaluation system based on main-control factors in the southwest mountain area.4. The relative weight value of the main-control factors are determined by Attribute significance of Rough Set theory. By the size of weight values the relative importance of the target can be clearly seen. The weight of main controlling factors will be considered in later establishment of evaluating model for the improvement of predicted precision of the model.5. Mapping relation between the safety levels and the main factors is established via Support Vector machine, and the safety evaluation model of slope in the southwest mountain area is built up via Rough Set-Support Vector machine theory. Users only need to input the corresponding value of the main-control factors of the railway slope safety evaluation, safety evaluation level can be outputted quickly and accurately by this safety evaluation model which greatly reducing the site workload and improving the efficiency of the slope safety evaluation.6. The safety evaluation model of slope in the southwest mountain area via Rough Set theory-Support Vector machine is applied to evaluate the high-steep slope along related high-speed railway. Compared with expert experience, the practicability of the model established in the paper has been checked up with the results demonstrating its feasibility.