Study On The Working Behaviour Of Underground Reinforced Concrete Bifurcated Pipe And Sensitivity Analysis Of Parameters

In recent decades, China has made considerable progress in the construction of hydroelectric power, but also made a lot of new issues. The design of large reinforced concrete bifurcated pipe under high water pressure is one of them. Currently, the guidelines for the design of reinforced concrete bifurcated pipe are not perfect, it is difficult to explore them clearly in theory, and their work conditions are not fully understood. Therefore, the study on the working behaviour of underground reinforced concrete bifurcated pipe is helpful to the construction of our pumped storage hydropower station. This article mainly has done the following work:1. The problem of minimum overburden encountered in designing hydraulic pressure tunnel is described. The current design criteria for determining the minimum overburden of hydraulic pressure tunnel are discussed, on this basis which offer theory reference for arrangement of the thickness of cover of the underground reinforced concrete bifurcated pipe.2. The problems in designing of the underground reinforced concrete bifurcated pipe are discussed, including choice of the lining patterns, the combined effect of surrounding rock and lining, the working behaviour under the internal and external water pressure, the design of the crack limitation calculation. In this chapter, the study focused on the design of the crack limitation calculation.3. On the basis of the large analysis software ANSYS, a 3-D non-linear FEM model of RC structure is proposed. The model can consider the nonlinear properties of rock and concrete, and simulate the work conditions of concrete after crack. It can achieve better results for the calculation of large RC structure.4. According to the calculating analysis of reinforced concrete bifurcated pipe in project of Mashan pumped storage hydropower station in Wuxi, the working behaviour of underground reinforced concrete bifurcated pipe under different circumstances is researched. Some suggestions are giving to the construction work, and the result of present study provides a reference for designing practice of an underground reinforced concrete bifurcated pipe.5. By means of sensitivity analysis in systematic analysing, based on the project of Mashan pumped storage hydropower station in Wuxi, the sensitivity analysis of influence of rock parameters on the stability of the underground chambers is carried out. In comparison of sensitivity factor of different parameters, the main sensitivity parameters ,the trend and possible degree for the influence of such parameters are discussed. Some suggestions are obtained, providing a valuable reference for the survey and field construction of underground engineering.