Analysed Study Of Process Simulation For Step Excavation Method Construction In Sdjacent Tunnel

Combining tunnel construcing research at home and aboard, numerical simulation and stability analysis of QiPanshi tunnel constucting are made by FEM software ANSYS, based on the design and constructing of QiPanshi tunnel in Nanping Fujian province. Studied according to the result of simulation stability of adjacent rocks, internal force and displacement of tunnel support, constructing method and stage of construction procedure in different adjacent rocks.Rocks, sprayedconcrete, bolt and second lining are simulated by plane42,beam3, linkl and beam3. Utilizing the DP(Drucker-Prager) yield criterion,tunnel model, constructing method and stage of construction procedure is built in differrent adjacent rocks. And the same time, method of excavation and unload is simply introduce. The procedure of tunnel excavation and supports is simulated through killing and activating the unit.The self-weight and tectonic stress is neglected in the paper, stress of rocks and internal force of support are sinulated in different adjacent rock, construction method and stage. The result shows that the biggest bending moment value and shear strength value and axial force is under middle of arch.(1)No matter which form of construction is adoped, there will be the major stress and internal force at the middle of arch and the major vertical displacement at the top of arch. With the increment of the adjacent rock level will be increased at the same place.(2)Forâ…¢level adjacent rock, when the rock is excavated through the three-step method and two-step method, the stress and internal force will be more well-distributed. Either of three excavating method has little effect on the displacement of the rock.(3) Forâ…£level adjacent rock, when the rock is excavated through three-step method, the first lining stress will be more well-distributed and the deformation will be smaller.(4)Forâ…¤level adjacent rock, when the rock is excavated through the three-step method and two-step method, the stress and first lining internal force will be more relatively well-distributed and the deformation will be relatively smaller.(5)Through the same excavating method under different adjacent rock conditions, the deformation will be smaller with the improvement of the rock conditions.Ultilizing numerical calculation to solve rock-soil engineering is a principal method in engineering design and stability analysis for constructing, but owing to lots of indeterminate underground factors, to ensure safety of tunnel construction and application information feedback must be emphasized. And, feedback information is utilized to adjust the tunnel construction.