Theoretical And Experimental Research On Earth Pressure Based Shield Cutterhead Torque

EPB shield construction because of its convenience, high safety factor, a small settlement close to the buildings and other characteristics have been widely used in underground engineering. Cutterhead torque of EPB shield machine as an important parameter in the project to be self-evident. At present cases which depend mainly on construction estimating an approximate range, and then to design cutterhead torque. It has a large estimated interval by this method, If the design is too big,it leads to a large increase in the cost of the project; If the value is too small which does not meet the construction requirements will appear stuck in the construction process, that may lead to delays in the progress of the phenomenon. Therefore, this paper will analyze the impact of factors on EPB shield cutterhead torque to start, to arrive at a theoretical model of the cutterhead torque, making him more in line with engineering, provide a theoretical basis for the future design of cutterhead torque.Firstly, by understanding the EPB in the actual construction of the shield tunneling process and the structure itself, get the influence of the factors affecting the cutterhead torque. Determine the overburden depth, soil properties cutter aperture ratio, a key tool in the form of several factors affecting the EPB cutterhead torque. By mathematical and mechanical knowledge Taking these factors deduced theoretical model EPB shield cutterhead torque.Secondly, In order to verify the correctness of the cutterhead torque theoretical model, we have developed a set of EPB shield construction simulation and test systems. The system includes test platform, earth boxes, cutting mechanism, transmission and hydraulic system. EPB shield construction simulation and testing systems to various types of soil formation under conditions simulating tunneling, test its process parameters, to provide a reference for the selection and construction of the shield.Thirdly, Relying on research into EPB shield construction simulation and test systems for the cutterhead torque calculation model theory.The system is used to verify the accuracy of the model. This section includes a comparison of theoretical and simulated values and the measured values of the cutterhead torque. By comparing the results of these three cutterhead torque calculation, it shows that the model is consistent with the current engineering practice. Developed EPB shield construction simulation and test systems can be very good for the soil to simulate the actual opening tap. In addition, through the system also studied the relationship between cutterhead torque and linear cutter aperture ratio, driving speed, cutter speed, etc.