Effect of existing nearby structures in tunnel excavation at TSC area

Abstract

Urban underground structures e.g. construction of subway tunnels are a crucial part of Geotechnical Engineering. Existing nearby structures have a significant impact on construction and excavation work. Until starting the key construction sequences, proper investigation and accurate analysis are needed. This study addresses the TSC area tunnel project. Considering the impacts and risks associated with building loads, layout must be carried out. In this perspective, numerical analysis can be classified as an important tool to evaluate the ground deformations, surface settlements and stress that occurred during the tunnel construction sequences. In this work, PLAXIS 2D, a finite element analysis application has been used to analyse finite elements. In the simulation Mohr Coulomb Model model has been used as a constitutive model of the soil. Laboratory tests have defined soil parameters that characterize physical and strength properties. Triaxial tests and consolidation tests obtained design parameters. It needs only a few integrated material parameters and can take into account the effect of the principal intermediate stress on soil deformation and strength, surface settlement, displacement vector, stress path influence on plastic flow direction and density and/or including pressure influence. It was found that the simulation of soil-structure interaction and behaviour according to the real life scenario in the Plaxis 2D system allows for higher safety factor. Therefore, with an advanced simulation tool Plaxis 2D, an advanced subway tunnel network can be designed for Dhaka city after proper ground movement prediction and tunnelling effect.