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3D Numerical Simulation to Consider the Effects of EPB Tunneling on the Existing Support System Bagherpour R., Mahdevari S. J. Civil Eng. Urban. 4(3): 256-260. 2014 ABSTRACT: The development of transportation in the large cities needs some new tunnels to be designed and constructed nearby existing tunnels. In this study, the adverse effects of excavation a subway tunnel using an Earth Pressure Balance (EPB) shield, under a sewage tunnel have been investigated. Both the relative position of the tunnels and the excavation procedure of the new tunnel affect the ground movements and existing tunnel lining. Hence, the effects of shield operation parameters such as the face pressure, grout pressure and overcut between the shield skin and the surrounding soil are studied using a 3D finite difference numerical simulation. In accordance with the results, the largest permanent interaction effects occurred at the crown of sewage tunnel. Furthermore, excavation of subway tunnel affects the support system of existing tunnel in the longitudinal section more than cross section. In addition, the most portion of support deformation takes place when the ground moves into the overcut space. However, these adverse effects decrease significantly by increasing the face pressure, grout pressure and Bentonite injection into the steering gap between the shield skin and the surrounding soil especially when the pressure of that is more than 3 bar. Due to EPB tunnelling, the internal forces variations in the longitudinal section of sewage tunnel are more than circumferential ones. Keywords: EPB Shield, 3D Numerical Modeling, Tunnel Interaction منبع: [Hidden Content] دانلود: [Hidden Content].,%204%20(3)%20256-260,%202014.pdf J. Civil Eng. Urban., 4 (3) 256-260, 2014.pdf