| Neighbourhood tunnel is a special tunnel type, the design and construction of neighbourhood tunnel with wide span have met new challenges because of some features of this tunnel type ,such as the span is little, excavated section is wide and special structure during excavating and supporting the two main holds of the tunnel.Usually, the category rock of the inducer and outlet section is weak,so the construction in these place is very important. Therefore, the mechanics relation of the neighbourhood tunnel with wide span under the construction is very complex. To understand the distribution of various kinds of stress in inducer or outlet section of this type tunnel, the stress-strain relation between the surrounding rock and supporting structure in course of the construction should be studied with the dynamic simulated method, which can explain theoretically the deformation law of the rock and structure in tunneling, and which is of great significance.Combined with the examples of Heshang tunnel, a FEM numerical model is established by ANSYS software, which is used to research into the inducer excavation, and the main content of the research in this paper as follows:1,The inducer category rock isâ…¤rock.According to practical situation,the two holes employ different excavating ways: the left hole is excavated by the pilot tunnel method, and the right is by the setback-type method.And the author analysed the stress , displacement of surrounding rock and the stress distribution of supporting structure under these two excavation methods ,which are generally used in tunneling.2,Then the author analysed the data monitored in Heshang tunnel, and compared them with the simulated date from the inducer. The results show that the numerical simulation is reliable.3,After excavation, some disease appears.The author analysed the reasons and adopted ways to deal with them. The monitor data indicates that the measurement to the disease is effective.
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