Providing a method to reduce the surface subsidence and preventing getting stuck on EPB-TBM - a case study

In recent years, along with the development and expansion of cities, population growth and vehicles, the construction of underground railways by mechanized tunneling is increasing. One of the common problems of EPB-TBM mechanized tunneling in weak and unstable areas is tunnel convergence, which causes problems such as getting stuck on EPB-TBM, subsidence and damage to buildings around the tunnel in urban areas. Due to the uncertainty in the soil parameters of the region, estimating the face pressure, thrust jacks pressure and cutter head torque at different kilometers is very important to prevent over-convergence of the tunnel, getting stuck on EPB-TBM and ground subsidence. Due to the uncertainty in rock and soil, in this paper the amount of face pressure, thrust jacks force, cutter head torque and ground subsidence due to tunneling in different kilometers in the construction project of the new Istanbul airport in Turkey using numerical software, PLAXIS3D 2020, is modeled. The modeling results show that the operator can increase the face pressure by preventing getting stuck on EPB-TBM. According to the results obtained in this paper, adjusting the face pressure, thrust jacks force and cutter head torque, in addition to solving the problem of getting stuck on EPB-TBM, will reduce ground subsidence and damage structures on the ground surface.