Deformation and crack analysis of tunnel structure subjected to static distributed load using Pseudoshell model

The objective of this research is to study the deformation and crack in shotcrete of tunnel structure subjected to distributed static load. Tunnel is modeled as two dimensional finite element model using commersial finite element software, namely ATENA (Advance Tool for Engineering Non Linear Analysis) version V5. Non linear material models for concrete and reinforcing bars are adopted. For deformation and crack analysis, pseudoshell model is adopted in which fictitious crack opening is assumed occur first in pseudoshell then propagate to the tunnel structures. Three variations of pseudoshell thickness of 30 mm, 60 mm and 100 mm are used. The development of crack opening and propagation of crack and its displacement due to the increasing of static load is therefore analyzed. The analytical results show that the dummy load and displacement at the crack opening width of 1 mm for the pseudoshell thickness of 30 mm, 60 mm and 100 mm are 48 kN/m and 48,33 mm; 55 kN/m and 42,75 mm; 67 kN/m and 35,5 mm respectively. The relationships between dummy load, displacement and crack opening width are closely linear.