THE MAIN GEOLOGICAL HAZARD PROBLEM FACED DURING UNDERGROUND SPACE EXPLOITATION AND PREVENTION COUNTERMEASURE IN CENTRAL CITY ZONE IN SHANGHAI

Now the exploitation velocity of underground space is increasing day and day, and the geological hazard problem produced by that appeared gradually. This paper firstly described the geological background of central city zone, then analyzed the geoenvironmental poblem produced during construction of underground project and usable feasibility. These problems include shifting sand conduced by sand and silty soil, and water inrushing of foundation pit conduced by underground water, and soft soil foundation deformation problem, and soil layer variational problem. Finally this paper advanced corresponding prevention countermeasure, which provided reference for plan and construction of underground space.