| Mineral resources provide the important materials for the material development. Our country is rich in mineral resources, and tens of thousands mining communities have been formed across the country for all types of mining. But mining has gradually brought about a lot of questions. Mineral exploitation not only occupied and damaged substantial land, but also resulted in lots of environmental issues, including degradation or disappearance of vegetation, soil erosion, collapse, landslide, debris flow, ground subsidence, river obstruction, disturbances of surface or groundwater systems, environmental pollution and etc.The endangering to the environment and impact on the regional sustainable development has taken growing attention, and its ecological restoration and reconstruction has been concerned generally around the world. Mined land reclamation is the process or actions of taking remediation measures to the damaged land by mining, in order to restore the conditions to the expectations of the availability status, and thereby recycle the land, restore the ecological balance, so that the production and construction can be developed healthily. At the same time land resources and environment are protected and sustained use. So now it is the inevitable requirement for the mining industry development to take effective mine reclamation measures to reduce the negative effects to the minimum. And it is an important issue inevitably involved by the world in subjects of development and environment.Tiger apex mine is an abandoned mine left over from the planned economy period in Jixian county of Tianjin city, which located north of the city 500m far, southern of the National Geological Park. The east and the north respectively connect to the scenic spots of geological relics in Fujun Hill and the geological nature reserves middle-upper proterozoic. Geographical coordinates of the mine are latitude 40°03 ' and longitude 117°23'. The transportation is very convenient with 102 National Road, Jin-wei Road, Tian-ji expressway surrounding the land, and with the railway line and national main line through the country.The mine area has lots of stromatolites resources. However, since mining stopped, the mine has been in idle status. In the process of exploitation and construction at the quarry, the original topography and vegetation suffered serious damage.On the one hand, a number of high and steep slopes with broken stones are formed, being potential geological disasters, bring about potential threat to the local people's lives and property by a security. On the other hand, it caused loose surface soil which has reduced ability to resist erosion resulting in substantial soil loss. Especially the dust and clastic at the surface of bare rock and soil caused serious dust pollution under the wind affecting Jixian county area and Jin-wei highway. All these phenomena are inconsistent with the development planning of Jixian county to be the medium tourist city famous at home and broad, and contrary to people's urgent need to improve their living conditions. And that has direct impact on the tourism economy development of the region as one of the economic pillars. Therefore, in order to protect the environment, build a people in harmony with nature, it is imperative to take effective measures for mine land reclamation.Through on-site investigation and related information, we can see that the natural mountains suffered serious damage by mining, and forming a large number of unstable slopes in Tiger apex mine. To successfully carry out mine reclamation we must study its stability firstly, and then made mine reclamation measures to restore the geological environment.Through the analysis of available information and on-site research, the thesis ascertained the engineering geological conditions of Tiger apex mine, summarized the factors affecting slope stability and evaluation parameters, and made a detailed summary of the current slope stability evaluation methods and analysis of its suitability. Slope stability was a puzzle with high nonlinear and indeterminacy. This kind of puzzle should be studied by nonlinear methods to insure the research achievements was objective and correct, which was the essential cause that the traditional can not make the evaluation objectively to the stability problem. So the thesis put forward using nonlinear methods to solve the problem.In order to explore a new method of slope stability evaluation, the nonlinear problem was studied for the first time based on the rough set theory (RS), support vector machine and extension theory methodology in this thesis. Through practically using the model in the slopes of Tiger apex mine, it was indicated that nonlinear method can evaluate slope stability more objectively, and based on the science reference mine reclamation measures were put forwarded.By means of the deep and system research on the slopes of Tiger apex mine, the primary results and conclusions were gained as following:1. Tiger apex mine was at lower area, having a single lithology on the whole, surface water not development, relatively simple structure, and joints of rock fracture development by the structure affecting. The phenomenon of gravity deformation can be seen everywhere. Being cut by many groups of joints, in gravity the rock displaced between the block to form dangerous rock mass. The irregular slopes were formed after artificial excavation, of which rock crusher, weakness, weathering, and there were partial fracture phenomenon and collapse after unloading.2. Based on analyzing the factors influencing the slope stability, the rough set theory is adopted to go to attributes reduction to them. The reduction results showed that the five reduced factors can include all the factors influencing the slope stability of Tiger apex mine, which offer the better index set for the following slope stability evaluation.3. The significance of attributes was figured out at first through the significance concept of attributes that belong to rough set theory. By the size of the weight values the relative importance of the target can be clearly seen, laying the foundation for determining weights in extenics analysis.4. In fact, the classification of slope stability is a function approximation problem between the characteristic of slope stability the influencing factors, namely the pattern recognition (a generalized function mapping relationship). And support vector machine has the unparalleled advantage in non-linear system than other methods. It can avoid local minimum points, over learning and other defects. This thesis set up a classification model of slope stability and the applied successfully it to the evaluation of slopes of Tiger apex mine.5. When using Support vector machine, testing the model is very important. After training study samples, we got the correct rate of 100% more than one model. In order to determine the model, test samples were used to examine the models. But we still got more than one model whose correct rate of 100%. This showed that it is not valid to examine models by individual samples. Aimed at this problem, the thesis examined SVM models by adopting the change tendency of single factor to slope stability degree. This method can examine the extension ability of the SVM evaluation model and avoid the limitation of the individual sample examination method.6. The determination of weight was critical when evaluate slope stability using extension evaluation method. Based on rough set theory a modified analytic hierarchy process (AHP) method was put forward. Through the size of the weight values by RS, we got the importance sequencing of the target, according to which the judgment matrix was determined .After that weight can be solved. This method avoided the deficiency of the traditional AHP depending on human experience to determine the importance degree of the target, so that the weight achieved greater objectively.7. Compared with the two nonlinear evaluation me thods for the slope stability of Tiger apex mine, it can be seen that the evaluation results by extenics and SVM are similar and accordant with the fact. It was validated that the nonlinear theories applied to slope stability evaluation are feasible and reasonable. And it was proved that the thesis selection and research of this dissertation are scientific and valuable practically.8. Considering that when it rains to the limit, the groundwater may be the role impacting the slope stability. For further evaluation the thesis took into account rainfall in the evaluation system. The results showed that rainfall has increased the degree of slope instability in the study area.9. Slope stability analysis was the scientific proof to the security of the region to carry out reclamation, and provided a reliable basis for restoration measures. Because of the existence of substantial instable slopes, cutting slope measure was required.After determining the safety angle of the slopes, and combined with the topography, landform features, reasonable reclamation treatment projects, and restore the vegetation measures were determined.
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