INVESTIGATION OF CONTACT BETWEEN SHIELD AND SEGMENT UNDER EXCAVATION ON SEGMENT CRACK BASED ON NUMERICAL ANALYSIS

Abstract

 To classify the cracks observed in used shield tunnels based on their occurrence factor, this paper proposes the estimation method of cracks caused by the contact between shield machine and segments during excavation. The distribution of stress on segment rings and the location of cracks are calculated based on 3-dimensional FEM by inputting the acting force calculated by 2-dimensional contact analysis. The 3-dimensional FEM is verified by means of simulation for an element test. The influence of stiffness at shield tail part, jack pattern and ground reaction coefficient and others is clarified based on parameter study assuming the real railway tunnels.