Study On The Formation Mechanism Of Ground Fissures In Shanxi Fault Basin

There are ground fissures in shanxi fault basin for a long time. The document recorded the ground fissures during Han period. Into Modern Times, especially since the middle, late20th century, as human activities stepped up and groundwater was pumped massively, the crust activities came into a active stage of new circulation. In Datong basin,Taiyuan basin, Linfen basin, Yuncheng basin, there had already occurred a large number of ground fissures, tremendous losses had been caused by ground fissures hazards, these active ground fissures made a serious threat on the people.In dissertation, by deeply understanding geological environment of shanxi fault basin, the ground fissures were arranged, the distribution rules were summarized, the formation conditions were analyzed, the genetic models and types were concluded. By means of exploration methods the genetic mechanism of the ground fissures was researched. The group mechanism of the ground fissures was studied. The development tendency of the ground fissures was estimated. The major works and results of this dissertation are as follows:(1) By field inspection and data collection,271ground fissures were ascertained for the first time in26counties, shanxi fault basin and e’mei platform, among them,115small ground fissures,66medium ground fissures,84large ground fissures and6huge ground fissures.(2) The developmental state of ground fissures was analyzed in shanxi fault basin, the distribution rules of ground fissures were found out for the first time, distribution along border mount fault, buried fault in basin, horst block, the edge of groundwater cone of depression.(3) Analysis of the relationship between ground fissures and deep tectonic, basement tectonic, active fault, ground stress, groundwater level,quaternary stratum thickness and heavy rainfall in shanxi fault basin, eight genetic models and two genetic types of ground fissures were concluded.(4) By the approaches of field investigation, data collection, measurement, exploratory trench, geophysical exploration, drilling and so on, the genetic mechanism of ground fissures was studied in Qingxue county. Qixian county-Taigu county, banpo village of Yuncheng, gaodui village of Linfen, suburb transformer substation of Wanrong county.(5) According to geodynamic setting of shanxi fault basin, the group mechanism of ground fissures was proposed, the development trendency of the ground fissures was forecasted.