Abstract

Info

Title:: Influences of Different Lining Structure Defects on Overall Safety of Tunnel Structure

Author(s):: SUN Tie-jun; WANG Wei; LUO Ming-rui; WANG Wan-ping; WANG Ya-qiong; Wenzhou Communications Investment Group Co., Ltd.

Keywords:: tunnel engineering; lining structure defect; load-structure method; numerical analysis; safety factor

Abstract:: In order to study the influences of different lining defects on overall safety of structure, the finite element numerical model was established by the loadstructure method based on the entity tunnel project. The numerical calculation was carried out under four conditions, such as normal condition, insufficient strength, insufficient thickness and void behind linings. The influences of different lining defects on structural safety were compared and analyzed. The results show that when the tunnel lining has the defects of insufficient strength and insufficient thickness, the safety factors of the insufficient parts are reduced, while the safety factors of other parts are almost unchanged. The smaller the lining thickness is, the smaller safety factors of the corresponding defect location is. When the void behind linings is large, the shear force and bending moment at the void behind lining and the adjacent position are both positive and negative mutation. So the stress and deformation modes of the lining structure are changed, the safety factors of the void parts are obviously reduced, but the safety factors of the lining structure in the adjacent area increase. The safety factors of the other parts dont change significantly, and are consistent with those of the normal condition.