抄録
The design and construction of the tunnel intersection is one of the critical part of tunnel projects .This paper present a numerical analysis of static behavior of Hakim tunnel intersection that is located in Tehran-Iran. Hakim tunnel is located in 22th quarter region Hakim highway. The tunnel consist of two distinct path ways went back which has three lines on each side. The intersection consist of two tunnel excavated with New Austria Tunneling Method (NATM). Geotechnical-structural-geodetic instrumentation as a practical engineering tool for systematic monitoring of tunnels and buildings in urbanized area were placed and layout of Hakim tunnel monitoring plan considering all requirements were planned and implemented. The NATM tunneling method is considered in numerical analyses. Extreme care is taken during excavation and immediate application of support media prevent unnecessary loosening of media. Many countries have adopted this method as the primary method of construction. This method is selected in this project. Based on special characteristics of Hakim tunnel, an extensive monitoring program has been developed for this project especially in junctions. In Hakim tunnel, monitoring process contains a plan of instrument installation (shallow and underground instruments) and reading plan. A 3d finite element model is implemented simulate the construction procedure with using FE based soft –ware ABAQUS. An elasto- plastic model with mohr-columb failure criteria is used to present the stress-strain soil and shotcrete behavior. In this model shotcrete is used for the support tunnel after excavation. The surface settlement, deformation of tunnel crown and forces in shotcrete due to excavation of intersection area has been studied. The results showed that the upper area of shotcrete in main tunnel is critical section for design support. In order to verify the accuracy of finite element model the results are compared with field measurement
