Finite element analysis of curvature precast polymer panel for temporary support of tunnels

Abstract

In the past few decades, underground railway systems as one of the accepted transportation system have become an integral part of populated cities, and consequently developing advanced structure to speed up the tunnels construction process become vital. Ceiling collapse is defined as the major failure in construction of tunnels that need to be concerned to prevent any hazardous on workers. Sprayed Concrete (SC) is the traditional structure that has been used for temporary support of tunnels under construction process. The disadvantages of SC such as tough preparation and installation process that is also time consuming procedure, is caused a necessary need to design new structure to be replaced by traditional cases. This study is concentrated on design and mechanical analysis of curvature polymer panel to be replaced by SC in tunnels. For this reason, Hard Density Polyethylene (HDPE) Polymer is selected due to its specific mechanical features such as high strength and stiffness to weight ratio. The tests of compression and tension are performed to extract the material properties and mechanical behaviour of HDPE polymer. A good study is done on mechanics of polymer materials to select an appropriate model accurate enough to model HDPE polymer. YEOH model is selected and utilized in Finite Element Analysis (FEA) using ABAQUS 6.9EF. Explicit Dynamic (ED) Procedure is used to simulate the hyperelastic deformation of HDPE polymer structures. The mathematical model and computational procedure are validated using simulation results of a three-dimensional (3D) model of a cubic HDPE polymer under compression load that compared well with experimental data. The established simulation procedure has applied on the proposed model of curvature HDPE polymer structure for temporary supports of tunnels. The actual loading and boundary condition in tunnels are tried to apply on the structure and the model is ran using FEM and ED procedure. The flexural strength response of structure is plotted as load-deflection curve to show the stiffness that can be tolerated with the curvature structure. A complete discussion is given on stress and hyperelastic deformation of the structure. The results are illustrating the advantage and disadvantage of designed structure and the possibility of utilize polymer materials in tunnelling process. The computational procedure is strongly recommended for design and analysis of polymer structures for different engineering application.