Abstract: In order to further discuss the safety and applicability of the longitudinal joint of the corrugated steel lining structure in tunnel, the flexural performance of the longitudinal joints of different types of assembled corrugated steel plates are studied, and 3 types of corrugated steel plate specimens of 200 mm×55 mm, 300 mm×110 mm and 400 mm×150 mm are selected for numerical simulation tests of joint flexural resistance. And then 12 simulated working conditions are designed, and the stress and deformation laws of different types of bolts, ultimate bearing capacity and deformation failure characteristics of flange plates under different bolt pretightening forces are discussed. Finally, the bolt stress, midspan deflection, ultimate bearing capacity, flange joint opening and plastic deformation failure of flange plates are elaborated in detail. The results show that: (1) The bolts are mainly deformed by tension and bending, and the inner bolts have a larger stress than the outer bolts, which makes it yield first. (2) The weakness of joint mainly lies in flange plate, which is prone to deformation damage. (3) The pretightening force of the bolts has a certain influence on the ultimate bearing capacity, midspan deflection and joint opening of the corrugated steel plates. (4) The flexural bearing capacity of big corrugated steel plate is about 1.36 times and 1.67 times of those of deep and middle corrugated steel plates, respectively.

Key words: tunnel engineering, corrugated steel plate, longitudinal joint, flexural performance, finite element analysis