The Study On Mechanism Of Ground Collapse Disaster And Its Dangerous Appraisal In Guangzhou

Ground collapse is one of the major types of geological disasters, which do serious harm to the national economy and people's lives and property and hamper the sustainable development of cities, so the study of its mechanism and fatalness appraisal has important realistic significance and extensive using value. Its result is used widely in reducing natural disasters such as providing disaster relief, civil administration salvation, urban construction, calamity insurance, environmental protection and sustainable development.The basic theory on ground collapse is discussed at first. Ground collapse is provided with these characteristics such as systemic, regionality, co-existing, periodicity. The ground collapse are caused by groundwater corrosion, vacuum corrosion, pressure blasting, gravity, vibration, loading, root corrosion or chemistry dissolveing.At the same time the ground collapse geo-disaster is studied from the perspective of natural disasters. A complete disaster process includes three factors: the environment pregnancying disaster, the cause of leading disaster, the disaster object.Guangzhou is located in Pearl River delta. Ground collapse has been very serious. Complex geology environment and obvious fault structure and drastic human activity lead to this situation. Ground collapse in Guangzhou has some obvious characters such as latentness, regionality, sociality and loss graveness. Ground collapse in Guangzhou is divided into two types: karst collapse and human-engineering collapse, the former has large amount but the later has the most serious losses. In recent years, the losses of ground collapse disaster in Guangzhou have ridden the growing trend. Human activity is one of the main factors. In Guanghua basin karst collapse is mainly due to excessively pumping groundwater, mining or heavy rains; human-engineering collapse in main urban attributes primarily to human activity including drainage role, artificial loading, artificial vibration, artificial excavating, surface water seepage or subway construction.The mathematical models and GIS are used for the fatalness appraisal study of human-engineering collapse in main urban area. The appraisement indexes are conceived through chooseing the factors such as fault, the stability of the earth's crust, the quaternary sediment lithology and thickness, bedrock lithology, groundwater dynamics conditions, surface and underground intensity of human activities. ArcGIS software is applicated involving in data collection, data management, data analysis and evaluation process, expressing.Finally, the fatalness classification chart of grade about ground collapse in Guangzhou is produced.The result tells us that there are five fatalness grades in main urban area, the most dangerous zone distribute...