The Research Of Aquifer Structure Variation And Water Resources Dynamic Change Of Group Mining Area In Changzhi Basin

Under the rapid development of economic,the high strength of coal exploitation have caused the change of aquifer structure,the dynamic evolution of heterogeneity in regional aquifer medium,affected the circulation evolution trend of groundwater seriously,and became the root causes of the groundwater resources shortage and destruction in coal mining area.This thesis started with the overlying strata movement caused by mining,based on the data analysis,used the methods of the similar material simulation,the field monitoring,and the on-site water injection(pressure)experiment,applied the principle of hydrogeology and fractal theory to study the thickness change and permeability variation of aquifer structure caused by coal mining.Furthermore,the water dynamic characteristics caused by coal mining were studied.This part of research based on the hydrogeological conditions and water resources condition of concentrated exploration area in changzhi basin.According to the local aquifer structure variation and water resources distribution caused by coal mining,the thesis has determined the division standards of water resources change incidence,and delineated the scope of the water resources change incidence in the studied mining area,provided the technical support for the studies of the groundwater circulation mechanism and the water resources redistribution after the aquifer structure variation.(1)From the perspective of hydrogeology,this thesis has put forward the concept of critical aquiclude,which could determine the thickness variation of the aquifer structure change.When stratum(?),the stratum location is the thickness variation of the aquifer structure change.The concept of critical aquiclude extends the connotation of "key layer" in coal mining theory.The aquifer space structure could be divided into water fluctuation zone and water plummet zone by the critical aquiclude.(2)The aquifer structure in water fluctuation zone basically followed the original structure of stratum,the water level changeed by the coal mining but the water resources do not leak,included decline period and recovery period.Overall,the permeability of mining influence area was 5 to 15 times bigger than the non-mining influence area,the biggest permeability appeared near the coal wall in mining influence area,and the smaller permeability appeared in the central of goaf.(3)The fracture development in the water plummet zone presented like zoning characteristics,the number,angle,space of fractures were obvious different in different areas.According to the characteristics of the fracture development,and combined with water injection test,the permeability characteristics of water plummet zone was divided into caving storage zone,fracture permeability zone,fracture strong runoff zone and stratifugic tube-flow zone.The mathematical expressions of max and real-time number of water storage in water plummet zone theoretically.(4)Based on the hydrogeological conditions and water resources condition of concentrated exploration area in changzhi basin,according to the local aquifer structure variation and water resources distribution caused by coal mining,the water resources change incidence was divided into serious water resources change incidence,medium water resources change incidence,general water resources change incidence,and non-water resources change incidence.