Abstract:

The influences of different staggered joint assembly angles of lining ring, different force transmission modes of annular joint surface and different unevenness of annular joint surface on longitudinal stress and cracking of shield tunnel segment are studied. Some conclusions are drawn as follows: （1） The influence of unevenness of annular joint surface on the stress of segment structure must be considered in design due to the dimension error of segment;the longitudinal nonuniform contact load caused by uneven annular joint may be either construction load or variable load in service stage.（2） The longitudinal load caused by uneven annular joint surface of segment is related to the segment of lining ring, assembling mode and transmission mode;the maximum longitudinal load produced by staggered joint assembling angle of 1/3 or 1/4 standard block is larger than that of 1/2 standard block; the maximum longitudinal load produced by convex platform transmission mode is larger than that by gasket transmission mode;when the segment is divided into blocks and assembled in the same way, the convex force transmission mode is easier to cause segment crack. （3）When the most unfavorable longitudinal load is used, it is recommended to take 1.0Δ（where Δ is the allowable error of ring width） as the design value of the ring joint surface irregularity;after the combination of the calculated longitudinal bending moment and the transverse internal force of the segment, the segment shall be reinforced according to the biaxial bias component, and the crack development width caused by the longitudinal bending moment shall not be greater than 0.1 mm.

Key words: shield segment, uneven contact, construction load, crack, structural stress