Study On Foundation Deformation And Stability In Old Mining-out Area Of Oil Shale

With the rapid development of the infrastructure, many of the infrastructure, such as civil construction, industrial plants, roads, railways, etc. have to built on or through the old mining-out area. Particular in Shanxi, Inner Mongolia, Shanxi and other major coal producing regions, due to a large number of mined areas and mine spoil heaps in the presence resulted in a shortage of local construction sites, at the same time in order to facilitate the production, convenient living, most mining civic construction, roads and railway have to build on the surface of the mining-out area which have ended the settlement. The mined rock activated under kinds of static load which coursed by the industrial plants or civil construction and dynamic load coursed by means of varies transport, all of this caused the mined rock falling again and result in surface residual deformation and even influence the normal use of the surface structures, or even caused accidents. Therefore studying on the stability and deformation of foundation in mining-out area is needed, which will direct the restore of the mining-out area land and construction of small towns.This paper combined mining-out area of oil shale studing the construction foundation deformation and stability. The content of the paper include six chapters. The first chapter is utilized to discuss the history and actuality of the subject and the sense of the study, find out deficiencies in the present study. Explained the purpose of this study, the main content and the technical routes. The second chapter of the paper analyzed the field survey data and existing data, presented the type and size of the proposed building, engineering geological conditions: environmental conditions, including geological, hydrogeology conditions, tectonic movement and seismic action of the study area, and analyzed the ground subsidence and deformation mechanism. The third chapter includes two aspects, first analyzed the existing mining data and geophysical exploration results to get the thickness of mined rock distribution, and based on terrain conditions and the thickness of mined rock distribution to get the engineering geology division result. Secondly by comparing influence depth of the additional stress of building foundation and thickness of mined rock to do the suitability evaluation on each engineering geology division of the study area, and identified the appropriate architectural layers of each engineering geology division. The fourth chapter introduces the probability integration method which is commonly used to calculate the deformation of the rock layer and surface of mining-out area. Write computer programs based on principles of probability integration method, determine the calculation parameters by engineering geological conditions and mining conditions, calculate the settlement, tilt, curvature, horizontal movement, horizontal deformation of mined rock in the condition of the effect of construction load. The fifth chapter introduces the finite element numerical method of nonlinear theory, combined with geological section of the study area established computation model, using the finite element analysis software geo-slope to calculate the development of stress and strain in building foundations by way of staged loading loads, and get the development trend of the stress-strain and the plastic zone as the increase building load. At last evaluate the stability of the foundation. The sixth chapter summarized the above research and given the final result of the stability of the building foundation, and make recommendations for further research.The research is belong to a relatively new subject at home and abroad, and it can direct the use of the old mining land. At present, there are no systemic reports regard to the building foundation deformation and stability of mining-out area under the load of the buildings, have not yet formed a complete theoretical guidance system. In this paper adopts probability integration method and numerical simulation method to research the deformation and stability of building foundations with mining-out area, and hopes it have positive meaning to guiding the practice of engineering.