STUDY ON LOCAL CRACKING OF SEGMENTS IN SHIELD TUNNEL DURING CONSTRUCTION
盾构隧道施工阶段管片局部开裂原因初探

Reinforced concrete segments are the basic structure units in shield tunnel. The cracking and breakage on segments will cause quality defect, and finally influence the durability of shield tunnel. During construction, crack appears on some segments near the bolt holes. In order to find out the reasons, first, full-scale positive and negative bending tests are applied to three pairs of standard segments. The tests indicate that the bending displacement do not cause these cracks. Afterwards, the finite element method is used to calculate the segments stress distribution under relative bending and torsional moments between two standard segments. The contours and cross-section stress curves of analytical results indicate that the relative torsion between segments causes the cracks during shield tunnel construction.