Numerical Simulation On Land Subsidence Of Hangu Region In Tianjin City

Land subsidence is a kind of geological disasters which is a threat of socio-economic development and people’s life, Hangu is one of the extremely serious area of land subsidence in the North China Plain. Because of the extensive exploitation of groundwater, land subsidence in the area becomes a serious impact on people’s production and life. Combined south-north water transfer project with groundwater plan of Tianjin Hangu, put forward program of groundwater exploitation and land subsidence prevention and controlThrough the discussion of which natural and geographical conditions, geological conditions and hydrogeological conditions in Hangu can be seen, owing to the deposition characteristics of Hangu, high compression of soil relatively thick, relatively wide distribution, the excessive exploitation of groundwater is very easy to cause serious land subsidence. The happening of ground settlement will lead to river flood control and shipping capacity, traffic lifeline is damaged, it is difficult to repair damage, buildings and structures of the subsidence and sea level relative rise to people’s production and life has harmful damage and economic loss caused by is immeasurable. Therefore, governance and preventing land subsidence in current economic development must cause high attention.Treatment and prevention of land subsidence premise is master the occurrence area of ground subsidence mechanism, factors, distribution and dynamic etc., and on the basis of the construction of the premise of computational model for the simulation of ground settlement, to further understand the degree of harm. The calculation method of ground subsidence is divided into two categories according to the construction form: one is mathematical statistics and stochastic statistical model, and the two is soil and water coupling model. Mathematical statistics and stochastic statistical model is simple, can not well reflect the settlement of ground subsidence mechanism and Application on the precision is not high trend analysis; water soil coupling model considering the interaction of soil and water, can very good explanation of ground subsidence mechanism, and according to the mechanism more accurately reflect the occurrence of land subsidence process and trend is common ground settlement calculation model. Therefore, the calculation method of this paper uses the soil and water coupling model.Through the construction of the three-dimensional unsteady groundwater flow model and soil compression model, the use of data and data from 2002 to 2007, after repeated identification and verification established in Hangu area, numerical simulation of land subsidence coupling model, and combined with the middle route of the South to North Water Diversion Project to Tianjin and Hangu water resources planning features, developed a set of groundwater planning scheme, according to plan the use of built coupling model to predict the 2015 to 2030, the ground settlement trend, prevention and governance of the area of ground settlement proposed some suggestionsBy coupling model results with measured data comparison found, Hangu ground subsidence center mainly concentrated in the Tanggu, Hangu and Hangu near; the ground settlement increased year by year, but the settlement rate but decreases, significantly inhibited the deeper settlement center of diffusion, reflecting the feasibility of groundwater exploitation scheme.