【摘要】 研究目的：为探明高水压大直径盾构隧道的破坏特征，以苏通GIL输电管廊盾构隧道工程为依托，采用“盾构隧道结构体加载装置”开展错缝拼装管片结构原型加载破坏试验，对管片结构的破坏过程进行分析，探明管片结构的破坏机理和承载性能，从而为高水压大直径盾构隧道的设计提供参考。研究结论：（1）管片结构形变呈“横鸭蛋”形，最大直径变化率为9.52‰，最大纵缝张开量为12.87 mm;(2)拱顶、拱底内弧面受拉开裂破坏，裂纹最大宽度分别为4.5 mm、11.5 mm，裂纹总长54.80 m，总数量为235条，以纵向裂纹为主；左拱脚、右拱肩外弧面受拉开裂破坏，裂纹总长64.70 m，总数量为65条，裂纹最大宽度0.1 mm;(3)管片破坏经历弹性、弹塑性及破坏三个阶段，管片开裂对结构整体刚度下降影响不明显，破坏机理为：裂缝深度增大，钢筋屈服，中心轴不断上移，核心混凝土有效承载面积减小，管片总体刚度不断减小，直到结构发展成为几何可变机构，使得弯矩和偏心距降低、位移增长，结构承载力下降，管片结构局部失稳破坏，管片极限承载荷载为2 827.2 kN，极限承载力安全系数为1.632;(4)本研究成果可为高水压大直径盾构隧道的设计提供参考。更多还原

【Abstract】 Research purposes: To investigate the damage characteristics of the large-diameter shield tunnel under high water pressure, a prototype loading failure test was conducted on a staggered-joint segment structure using the “Shield Tunnel Structural Loading Device”, based on the Sutong GIL comprehensive gallery project shield tunnel. The failure process of the segment structure was analyzed, and the failure mechanism and bearing performance of the segment structure were explored, to provide a reference for the design of high water pressure large-diameter shield tunnels.Research conclusions:(1) The deformation of the segment structure shows a "horizontal duck egg" shape, with a maximum diameter change rate of 9.52‰, and a maximum longitudinal seam opening of 12.87 mm.(2) The inner curved surfaces of the arch top and the arch bottom are subjected to tensile cracking and failure, with a maximum crack width of 4.5 mm and 11.5 mm, respectively. The total length of the cracks is 54.80 m, with a total of 235 cracks, mainly longitudinal cracks. The outer curved surface of the left arch foot and the right arch shoulder are subjected to tensile cracking and failure. The total length of the cracks is 64.70 m, with a total of 65 cracks and a maximum width of 0.1 mm.(3) The failure of the segment goes through three stages: elasticity, elastic-plastic deformation, and failure. The cracking has little effect on the overall stiffness reduction of the structure. The mechanism of the segment failure is that as the depth of the crack increases, the steel bars enter a yielding state. The central axis of the segment continuously moves upward, reducing the effective bearing area of the core concrete, resulting in a gradual decrease in the stiffness of the segment structure until a geometrically variable mechanism is formed. The decrease in bending moment and eccentricity, the increase in displacement, and the decrease in structural bearing capacity lead to local instability and failure of the segment structure. The ultimate bearing load of the segment is 2 827.2 kN, and the safety factor of the ultimate bearing capacity is 1.632.(4) The research results can provide a reference for the design of high-pressure, large-diameter shield tunnels.更多还原