Research Of Ground Subsidence & Methods Of Controlling Subsidence Around Haihe River

The land subsidence is quite severe in the north part of our country, especially in Tianjin. It is influencing our lives and productions seriously. The principle and causation of the land subsidence around Haihe River must be studied eagerly with caution. It becomes an earnest problem to find out some reasonable measures to control the land subsidence.Based on the views mentioned above, the nature and man-made causations of the land subsidence are carried out through analyzing the history and actuality of the land subsidence around Haihe River in Tianjin. After the brief introduction of geological structure, hydro geology, and geotechnical layer geology, the reasons of stratum and physiognomy around Haihe River are shown. Then subsidence of the history and present is given out and compared, and the subsidence at present is affected by history, also contribution of different layer for subsidence is illuminated summarily. After that, various reasons of subsidence are explained in details, and the conclusion is that nature force is one of the essential factors around Haihe River, also the secondary-consolidation deformation of soft soil cannot be ignored, as far as the man-made causation is concerned, the excess exploitation of groundwater is another one essential reason of land subsidence, although the exploitation of groundwater is under control strictly, however, the consolidation deformation lasts a long time after groundwater is exploited, which causes subsidence to some extent.At last suggestions for land subsidence controlling are presented based on the reasons shown above, including exploration for new real time, fleet and effective monitoring methods, foundation of GIS and database, research for theoretical model of land subsidence, and the controlling of exploitation and artificial recharge of groundwater. At the end, advice is mentioned for density and dimension ratio of building.