SHALLOW GEOLOGICAL CONDITIONS AND RELATED GEOLOGICAL HAZARDS IN SHANGHAI

摘要

Practical experiences show that geological disasters, such as liquefaction and quicksand, landslides, excavation collapses, and seriously differential settlements and cracks of buildings etc., occurred definitely related to the physical and mechanical properties of subsoil in Shanghai. That is to say, there is a close relationship between the geological conditions of shallow layers and geological disasters occurring during the construction of underground projects in the Shanghai area. The age of sediments usually determines their physical and mechanical properties. The shallow clayey and sandy strata in Shanghai area may cause geological disasters during the underground engineering activities for their physical and mechanicals properties. So, the forming time, and the distribution of thickness and depth of the ceiling bed of clayey and sandy soils, has been used as zoning principle. And according to this principle, 35 types of sub-areas are proposed for the analysis of geological disasters in soft soil district. At the same time, Shanghai area has been divided into 15 sub-areas belonging to 9 types, according to the by the zoning approach proposed.