Geo-environmental Suitability Assessment for Shallow Foundition Pit in Urban Zhengzhou City Based on GIS and AHP Methods

Abstract

With the objective of the security and sustainability of underground space, the geo-environment suitability assessment for shallow foundation pit was conducted by GIS and AHP methods combining with the characteristics of the study area on the basis of the investigation of the current exploitation of underground space and the geological environment conditions in Zhengzhou City and the advanced experiences at home and abroad. Computer technology provides powerful tools and methods to the geo-environmental suitability assessment of underground space, and supports decision-making and planning. In the research, the suitability of geo-environment was assessed using the multi-objective linear weighted function model. The results indicate that the elements influencing the geo-environment suitability of shallow foundation pit in the study area mainly include stability of foundation pit, active earth pressure of slope, and shallow groundwater depth and water enrichment of aquifer according to the impact of evaluation factors on the foundation pit engineering. The results showed that the suitable area with an area of about 96.2 km2 is located to the west of Beijing–Guangzhou Railway, the medium-suitable area with an area of about 174.4 km2 is located to the east of Beijing–Guangzhou Railway and to the west of the Beijing-Guangzhou high-speed railway, the poor-suitable area with an area of about 111.3 km2 is located to the east of Dongfeng canal-Jingguang high-speed Railway and we should particularly focus on the impact of surface water, groundwater, soft soil and land subsidence during construction. The application of GIS and AHP method provided key technical support for the assessment. The geo-environment suitability evaluation of the foundation pit engineering by GIS and AHP methods has a strong pertinence and can offer technical assistance for the exploitation of underground space in Zhengzhou City.