Assessment And Prediction On The Land Subsidence Of Tong Chuan New Area Caused By Ground Load

Land subsidence is a kind of geological hazard which is influenced by human factors and natural factors. It contribute to the soil volume compression and downward displacement in vertical direction.land subsidence is occurring slowly,widespread,long time, difficult to control,and has complex formation mechanism. Tong Chuan new area is significant in connect the central Shaanxi plain to northern Shaanxi. That is the key construction area in national high-tech industrial development zones.In recent years,with development of urban construction, There is an upward trend of land subsidence in Tong Chuan new area.The government has already limited exploitation of groundwater。Consequently, research of the impact of urban building load on land subsidence has utilitarian value to the urban construction sustainable development in this area.Taking Tong Chuan new area as research area: ascertained the geological environmental constructions,such as meteorology and hydrology, landform, geologic structure, stratigraphic texture, hydrogeological condition etc, based on the data which we collected and measured.Based on the confined compression test,we obtained soil’s preconsolidation pressure and consolidation states.During the testing data processing, the nonlinear equation can be obtained to describe the variation of the compression coefficient with consolidation pressure;Three types of nonlinear compression models were summarized for clay;and soil compression characteristic is evaluated. Based on test and collecting data,we set up the foundation settlement model, and taked settlement calculation caused by load,which respectively using layerwise summation method, numerical simulation method and stress path method.The study area’s land subsidence was evaluated and forecasted based on the calculation results, land utilization actuality and land subsidence existing information.