| As a heavy chemistry engineering energy base, Shanxi is known as a coal centre in China. The development of coal industry has brought about prosperous economy and become the main industry. With extensive mining of out-of-order, the big area and large-scale goafs have become in many regions of our country. Because this is the factor which restricts the construct of important basal engineering (for instance : super-highway, modern railway, airport, the project of diverting water from the Yellow River and eastern transfer of western gas and so on) and the small towns planning. So, the stability research of the building foundation with goaf is propitious to disposing surroundings of diggings, utilizing the soil of diggings, construct of important infrastructure and small towns planning.It is a newer topic at home and aboard for the law of deformation and destruction and evaluating stability of building foundation with old goaf. We can not see the overall basic theory system. Many main problems have not still been absolved completely in theory and practice such as mechanism of sinking and deformation and the stress statement of the foundation with building loads ,incontinently and variety of rock seam above goaf , harm of mechanics strength after rock seam broken and the stability and the law ofdeformation of building foundation .It isn't make it extensive application for treatment technology of foundation with goaf until they are well absolved. This topic is very useful for the design of foundation treatment and that technology expansion.Taking the old goaf of Xinzhi Colliery in Huozhou of Shanxi as a test example and adopting several research methods(such as site test, experiment of analog simulation and numerical simulation) , this topic inquiries into some factors (different building load, relative position ,depth mining, ratio of depth mining and thickness mining and the thickness of loose seam ) in detail which affected the stability of building foundation ,at the same time ,it also studies at length law of stability and deformation of building foundation with old goaf. Some main achievements obtained as below:(1) Study of the law on the movement of overburden seam and deformation of ground's surface in different geology mining conditions, analyzing depth mining and loose seam's thickness of the effect on the three zones , sinking value and the movement and deformation value of ground's surface.(2) In terms of fractal geometry theory, it studies the evolving law of fractal crack of mining rock, and analyzes the develop instance difference among the full sinking area insufficient sinking area and the zones of goaf, and founds the relative relationship between the crack and expansion 's coefficient, the overburden rock's sinking coefficient and mining rock's fractal dimension.(3) By using the harm mechanics theory, it studies the harm law of mining overburden rock, and analyzes the harm difference among the fullsinking area , insufficient sinking area and the zones of goaf ,and founds the relative relationship between harm variable and the push of the working surface.(4) Based on the result of analog simulation, it points out four structure types of overburden rock mining destruction , and analyzes the activate mechanism of overburden rock of old goaf. It also analyzes the instability form of piece crack structure rock and provides it's stress balance condition in terms of R-S theory.(5) By the results of analog simulation and numerical simulation, it studies at length different loads ,load position, depth mining , ratio of depth mining and thickness mining and loose seam's thickness of the effect on the stability of building foundation with goaf, and inquires into the general laws of the stability of building foundation with goaf.(6) It puts forward the distinguish index of the stability of building foundation , namely, critical ratio of depth mining and thickness mining .
|
PDF Full Text Request