Research On A Study On Steel Reinforced Concrete Shaft Wall Thermal Stresses And Temperature Of Frozen Shaft Lining

The mass concrete structure could produce large tensile stress due to temperature change. The tensile stress can be controlled in the allowable range by controlling the temperature of mass concrete. The factors affecting concrete temperature are various and the cracking mechanism of concrete is complicated. It is more difficult to contrl concrete temperature. The impact of various variable factors and the development of concrete cleft are impossible to accurately simulating and forecasting up to now. In this thesis, it is based on the background of mass concrete and high performance concrete used in the wall of shaft on Dingji of Huainan Mining Group. On the basic of concrete hydration heat analysis theory, the application of heat conduction equation of controlling concrete cleft, the boundary conditions and initial conditions for thermodynamics relationship are described. The explicit and implicit methods of finite element are compared. The thermodynamic parameters are obtained by concrete hydration heat simulation analysis. After determining the thermodynamic parameters of concrete.The temperature field and stress field about the wall of shaft under different frozen processing conditions are discussed. The thermodynamics unit SOLID70ANSYS software is applied to carry out simulation thermal analysis of temperature field, temperature stress and strain. Meanwhile, the method of theory analysis, In-situ measurement and numerical simulation are used. Some research works have been done as following:1. The experimentation is done for shaft lining’s high-strength and high-performance concrete, in the precondition of using super plasticizer, then through the approach of triple-mixed mineral additions-fly ash, silica fume and milled slag, the concrete not only fulfill the request of concrete’s properties of high strength and early strength, but also advance concrete’s late strength and durability.2. On the base of physical and mechanical properties of frozen soil and hydration heat of concrete, analyze the performance impact of concrete strength by the different components of the shaft lining concrete of freezing construction method and the mechanism of hydration heat production and calculation method on shaft sinking.3. Through the monitoring of temperature and stress in shaft lining and frozen wall, it is obtained that the varying of temperature field stress field and frost heaving pressure variation and sidewall reinforced concrete force law by freezing construction method sinking construction process.4. It is obtained that the heat capacity, coefficient of heat conductivity, and other basic mechanical property by the physical and mechanical experiment.5. Concrete hydration heat temperature rise model is calculated by the method of exponential, hyperbolic, and the composite exponential. Comparison of the calculated results and the measured average temperature is to determine the appropriate hydration heat temperature model.6. Through the consideration of freeze borehole wall temperature field, it is established that the numeric calculation medal of concrete hydration heat. The temperature field on the frozen wall and the characteristic distribution of temperature are obtained by using software of ANSYS of finite element program.7. Base on the result of temperature field’s calculation, three different calculation programs are applied. The temperature stress distribution on the shaft wall has been produced by introduction of results of temperature field and three kinds of mathematics operation. The temperature field on the shaft wall is figured out by the method of finite element.