Site Stability And Engineering-Geological Environment Quality Evaluation Of Donglongmen Shantytowns In The Mentougou District

This paper is based on the Donglongmen shantytowns improvement project, Mentougou District, Beijing. After the research of the pre-geological data, the AHP-fuzzy method is the most suitable one for the environmental and geological conditions evaluation work in the study area, combined with geographic information system (GIS) in the evaluation process. By using this method, finally get conclusions of environmental geological conditions and the construction site suitability evaluation of the study area, which provides a reliable basis for the planning work. At the same time, the study found:1. After the studying of the mined geological disasters by field survey and data analysis, ground fissures and surface collapses which caused by the underground mined were not found in the study area.2. According to the geological and mining conditions, as well as its spatial location and planning area relations, the stability of the surface affected zone was divided into three categories, which are the slightly affected zone, the more seriously affected zone and the medium severely affected areas.3. After analyzing the impact which the shallow and deep gob put on the surface, comprehensively considering the geological environment, the study area is divided into three categories, based on the result of the AHP-Fuzzy method, which are the appropriate area construction site, substantial appropriate area and the weak area.4. After some simple ground treatments, large buildings can be built in the appropriate area which can provide adequate bearing capacity; In the substantial appropriate area, it’s suitable for middle and low rise buildings in low density; In the weak area, considering the unstable ground cover gob, it’s more suitable for some landscape garden, based on topography and landscape of the region.5. Site stability, quality and suitability of the engineering-geological environment are controlled by multiple factors, and every factor act on them by different contributions. By using the AHP-Fuzzy method, it enables the factors, which include in the geological environment system, to be truly and effectively involved in the evaluation, and the evaluation results are real reflection of the comprehensive contribution of the various factors. This evaluation results can objectively reflect the real situation, and it can provide reference to the initial planning works.