Underground Geological Environment Quality Evaluation Of The Daxing Planning Town In Beijing

As the city space becoming more and more crowded, scientific utilization underground space has become an inevitable trend and an important guarantee for sustainable urban development. Underground geo-environment quality assessment can evaluate suitable zones and high-risk zones and provide the basic geological data and disaster prevention for urban planning and constructing.This paper is based on the planning Daxing Town early regional engineering geological survey project. Through the comprehensive study of existing geological data, the AHP-fuzzy method is the most suitable one for the environmental and geological evaluation work in the study area, combined with geographic information system (GIS) in the evaluation process. By using this method, we finally get conclusions of environmental geological conditions and the construction evaluation, which provides a reliable basis for the planning work. The main contents are as follows:(1) Analyzing the factors which affect the quality of geological environment .It provides the basis for establishing the geological environment quality evaluation index system and grading standards.(2) Adopting AHP method to set up the model for analysis on the principle of geological structure, hydro geologic condition and geological disasters. After each factor has been weighed,using the theory of Fuzzy comprehensive evaluation to evaluate the suitable intensity of underground geological environment, which was classified four quality grades (quality gradeⅠ-Ⅳ) .(3) Geographic information system (GIS) is used to get the underground geo-environment quality maps of the shallow space (0-10m) and the second shallow (10-30m). At the same time, characteristics of the geological environment and the main environmental geological problems are expounded.The results can objectively reflect the real geo-environment situation,which provide a reliable basis for the study area.