银川城市地下空间开发的地质安全风险分析

城市地下空间受地质环境的影响和制约, 评价地质环境的安全成为地下空间开发的先导问题。结合银川市地下空间资源调查和区划, 选择了地震(活动断裂和场地地震效应)、砂土液化、富水砂卵石层、地基承载力和地表载荷等因素作为评价因子, 在分别确定各要素空间分布的基础上, 进行了单因素的地质风险分析; 采用层次分析和乘积标度相结合的方法, 进行银川市地下空间开发的多因素地质安全风险综合评价。结果表明: 银川市地下空间开发的最主要制约因素是地震和砂土液化; 地质风险的强风险区面积最小, 占总面积的4.10%, 中风险区面积占19.69%, 弱风险区面积最大, 占41.07%, 低风险区占35.13%。这为银川市地下空间开发建设等提供地质参考。

Geological Safety and Risk Analysis of Yinchuan Urban Underground Space Development

The use of urban underground space is affected and restricted by the geological environment. Evaluation of the safety of the geological environment is the foremost issue for the development of underground space. We conducted a geological resource investigation and regionalization of the Yinchuan urban area, and selected the evaluating factors namely, earthquakes (including active faults and site seismic effect), sand liquefaction, rich water sandy aquifer, soil-bearing capacity and surface building load. The geological risk of each factor was analyzed. Subsequently, a comprehensive evaluation of the factors of geological safety and risk in underground space development was conducted using the analytic hierarchy process and a more flexible multiplication scale method. The results showed that in the Yinchuan urban area, the main controlling factors are earthquake and sand liquefaction for the underground space development. The high-, moderate-, and low-risk areas comprised 4.10%, 19.69%, and 41.07% of the urban area. The very low-risk area comprised approximately 35.13% of the urban area. This study provides an important geological reference for underground space development and construction in the Yinchuan urban area.