Study On The Simulated Model Test Of Shield Machine's Working Parameters Applicable To Different Stratums And Its Theoretical Investigation

With the widely use of shield tunnel method in the construction of subway, underwater tunnel and underground pipeline projects, great success has been achieved already. Since China is a large country with many complex geological conditions, the boring effect and performance of shield machine working in different stratums will change greatly. In order to form the design theory and principle of shield machine applicable to different stratums, it is necessary to take more fundamental experiment research on soil-shield machine system. Therefore, it can not only control and reduce the tunnel construction cost, but also guide the design and construction of shield tunnel scientifically.Combined with the national 863 program, study on shield machine applicable to different stratums and its similar model test is carried out. The EPB shield machine excavated in typical sand stratum of Beijing area and soft ground of Shanghai area are taken as research background. At the same time, simulated model test and numerical analysis are employed to study the adaptability issues of soil-shield machine system, and the main work can be described as below.(1) Based on the summarization of the domestic and foreign experiences and the lessons learned from shield tunnel construction cases over the past 100 years, a clear definition is firstly made on the theory of shield machine applicable to stratum characteristics. Meanwhile, the concept of soil-shield machine system is proposed in this thesis, i.e. studying the working parameters of shield machine and soil property as a whole. Subsequently, the scaling laws of model test for this system are derived, which can provide reference to conduct similar tests in the future.(2) Model stratums of sandy and clay layers are stimulated with artificial materials successfully. Then the model tests are carried out to study the adaptability of machine working parameters to soil property. The test results revealed the adaptive relation between the stratum characteristics and the main construction parameters of shield machine, such as jacking force, cutter torque, advance rate, rotation speed and cutter open rate, as well as the internal relationship among these parameters, which can be used to guide the optimization of shield tunnel method.(3) Further study showed the inherent connection between the change of machine...