锈蚀铸铁管片接头力学性能数值模拟研究

Numerical Simulation Study on Mechanical Properties of Rusty Cast Iron Pipe Segment Joints

摘要:

为探究锈蚀对地铁隧道铸铁管片接头压弯力学性能的影响，以香港地铁铸铁管片为研究对象，运用ABAQUS软件建立有限元模型，设置接头锈蚀厚度（0、2、4 mm）、正负弯矩作用以及螺栓失效等工况进行数值模拟计算。结果表明：锈蚀会显著削弱接头螺栓的力学性能及接头的抗弯极限承载力，同时增大接头的几何变形能力，且削弱效应会随着锈蚀厚度的增加而加剧；负弯矩作用下，锈蚀的削弱作用强于正弯矩；螺栓失效后，管片抗弯性能进一步降低，产生与螺栓正常工作时相同应力或应变所需弯矩的降幅达29%～33%，接头失稳风险显著升高。研究结果可为锈蚀铸铁管片接头的安全评估与维修加固提供理论依据。

Abstract:

To explore the effect of corrosion on the flexural mechanical properties of cast iron segment joints in subway tunnels, a finite element model is established using ABAQUS software based on the cast iron segments of the subway in Hong Kong. The numerical simulation calculations are conducted under conditions such as the rust thickness of the joint (0, 2 and 4 mm), positive and negative bending moments, and bolt failure. The results indicate that corrosion significantly reduces the mechanical properties of the joint bolts and the ultimate bending load-bearing capacity of joints, while the geometric deformation capacity of joint is increased, and this weakening effect intensifies as the corrosion thickness increases. Under negative bending moments, the weakening effect of corrosion is stronger than under positive bending moments. After bolt failure, the bending resistance of the pipe segments further decreases, with the bending moment required to produce the same stress or strain decreasing by 29% to 33%, and the risk of joint instability significantly increases. The research result can provide a theoretical basis for the safety assessment and repair/reinforcement of corroded cast iron pipe segment joints.