Study On Construction Process Of Earth Pressure Balance(EPB) Shield Machine In Loess Ground

It is the first time that shield tunnels have built in the loess ground in China. So it is valuable and practical for XiAn tunnel's construction in the future to study the soil sedimentations.Based on the twin shield tunnel of the XiAn Metro, laboratorial model test and numerical simulation are used to simulate the dynamic construction process with Earth Pressure Balance Shield Machine, research the change laws of the ground displacement in the parallel tunnels during the dynamic shield construction process. The main work of my thesis is as follows:1,Based on the truth that the disturbance of the shield construction to the ground is essentially the disturbance of the loess, the sources of the disturbance has been analyzed; At last the computational method of the mechanical effect,the geometrical effect and the secondary consolidation effect of the soils was put forward.2,The parameter which can show the characteristic of the shield-ground system was analyzed, and then the parameter which can evidently influence the result of the test was chosen.3,The universal laws of the ground displacement during the dynamic shield construction process was got by analyzing the data of the model test; The dynamic construction process in loess ground was simulated by three-dimensional numerical simulation.And the change laws of the ground displacement during the dynamic shield construction process in loess ground was researched.