Abstract: In order to discuss the possibility of integral pouring of the inverted arch and its filling, and solve the dispute between separate pouring and integral pouring of the inverted arch and its filling. Loadstructure model is established by numerical calculation to analyze different effects of inverted arch filled at different pouring time on stress performance of lining structure under three situations for filling body, i.e. without central drain (pipe), with central pipe and with central drain. The main conclusions are as follows. (1) When the filling of inverted arch is without central pipe (ditch),the integral pouring of inverted arch and its filling has no effect on the stress performance of lining structure.(2) When the filling of inverted arch is with central pipe, the integral pouring of inverted arch and its filling have less effect on the stress performance of lining structure; whereas the stress is greater at the center of filling surface, exceeding seven times greater as which in working condition of separate pouring. Moreover, the thickness of filling body at upper part of central pipe is small, which is unfavorable to tensile strength and prone to crack and damage, thus inverted arch and its filling should not be poured integrally. (3) When the filling of inverted arch is provided with central drain, the integral pouring of inverted arch and its filling is adverse to the overall stress of lining structure, which is not recommended.

Key words: railway tunnel, inverted arch, filling of inverted arch, separate pouring, integral pouring, numerical simulation