Study on the Bending Failure Mode and Mechanism of Corrugated Steel Lining Flange Joints
(1. Yunnan Communications Investment Group Yunling Construction Co., Ltd., Kunming 650041; 2. Department of Geotechnical Engineering College of Civil Engineering, Tongji University, Shanghai 200092; 3. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092)
Abstract：
To compare the mechanical performance of flange joints under positive and negative bending moment con? ditions, four-point bending full-scale tests of corrugated steel lining flange joints were conducted. The failure modes, M-θ curves, and strain of corrugated steel under both conditions were analyzed. A three-dimensional refined finite element model was then developed and validated based on the experimental results, from which the stress curves of the bolts and flange plates were extracted to reveal the failure mechanism of the flange joint. The study results show that: (1) The failure modes of the flange joint under positive and negative bending moments are flange plate buckling failure and failure due to the local reaching of stress limits in the flange plate and bolts, respectively; (2) The M-θ curves of the flange joint exhibit a three-stage growth trend, with the joint stiffness and ultimate bending moment under positive bending being 119.9% and 124.2% of those under negative bending moment, respectively; (3) The stresses in the corrugated steel, bolts, and flange plate under positive bending are all smaller than those under negative bending. Under positive bending, the strain in the trough and middle of the corrugated steel first undergoes tension and then compression, while under negative bending, the strain in the trough and middle remains in tension. In both conditions, the flange plate reaches yielding at the end of the elastic stage, but the bolts have not yet yielded.
2025, Vol. 62 