Secondary lining cracking always occurs in existing tunnels when the tunnel passes through the weathered argillaceous siltstone layer, which seriously affects the safety of the tunnel. In order to study the mechanical properties of weathered argillaceous siltstone and the cracking law of the secondary lining, this study analyzes the relationship of accumulative plastic strain between the dynamic stress amplitude and static deviator stress, as well as the cracking law of the secondary lining of the sample. The results show that under cyclic loading, there are obvious accumulative plastic strain in weathered argillaceous siltstone; the bearing capacity of the secondary lining structure at the biased part shows an evident increase than that of others with cracking generating faster. The research results provide a reference for the safety and operation of the tunnel that runs through the weathered argillaceous siltstone layer.

既有隧道在穿越风化泥质粉砂岩层时，往往会发生二次衬砌开裂，严重影响隧道安全。为研究风化泥质粉砂岩的力学性能和二衬的开裂规律，本文分析了动应力幅值与静偏应力的累积塑性应变关系，以及二衬的开裂规律。样品。结果表明，在循环荷载作用下，风化泥质粉砂岩存在明显的累积塑性应变；偏斜部位二衬结构的承载力较其他部位明显增加，开裂产生速度较快。