The Study On Formation Mechanism And Prevention Countermeasures Of Ground Fissures In The Future Science And Technology City Of Beijing

Ground fissure is a kind of ground deformation disaster in geological disasters, the concealment and great harmfulness are its characters, not only ground fissure would cause cracking of the building, dislocation of underground pipeline, fracture and partial collapse of the roads, and reduction of the value of land use, but also cause a series of environmental problems,which would cause a great threat to people's life and production.Beijing is the capital of the People's Republis of China, it is the world-famous historical and culture ancient city. It is the politics,economy and traffic center of the whole country. In the past 20 years,the devolopment of constructions of Beijing are very fast. This kind of development is not only shown as constant expasion of level range,but also reflect to the development of ground and underground sapce. Human engineering activities have a great demand on groundwater resources and the exploitation,which lead to the development of poor geological phenomena such as ground fissure and differential settlementBasing on field survey,the paper which combined with a large number of drilling, trenching, and geophysical exploration, and laboratory tests,has revealed development characteristic of ground fissure of national smart grid in future science and technology city of beijing, analysised formation mechanism of ground fissure,summed up the mechanical expansion mode and scope of hidden fissure, discussed the hazards of engineering construction caused by ground fissure, and proposed control measures in disaster prevention significance,these have far-reaching theoretical and practical meaning not on awareness of formation mechanism of ground but on disaster prevention and mitigation task.In this paper, results and innovation were achieved as follows:(1) the ground fissures are almost vertical in geometry, vertical displacement is more evident than horizontal extension and horizontal twist.(2) space distribute of ground fissures are mainly controlled by HuangZhuang-Ga oLiYing fracture,and its over-conventional activities are mainly affected by the ground subsidence,which is caused by over-exploitation of underground confined water.(3) possible failure modes of hidden ground fissure were summed up,and mechanical analysis method was used to calculate the limit affected zone of fissure width(4) according to the result of situ-field investigation of ground fissures,combined with land subsidence and monitoring data have been obtained,we have given the recommended value of activity parameter of ground fissure,width of influnce and minimum safety avoidance distance (5) refer to the prevention and treatment experience of Xi'an,combined with actual situation of the site, we have proposed general recommendations of the site.