地铁大直径过江盾构隧道典型病害研究

Typical Diseases of Metro Large Diameter River Crossing Shield Tunnel

基于南京地铁某大直径过江盾构隧道的病害调研结果,探讨区间隧道典型病害特征,并初步探讨部分病害的直接成因。研究结果表明:区间隧道的典型病害主要有管片接缝变形、管片裂损、隧道渗漏水、内部结构裂损。区间内管片接缝错台量的统计结果满足正态分布要求,且下部测点的错台量小于上部测点的错台量;错台量超限率<1%,封顶块纵缝的错台量相对其他位置较大。在管片裂损情况中,角部破损情况占比最大。牛腿开裂在隧道内较为普遍,开裂与管片环缝和预制烟道板接缝的位置有关。中隔墙裂缝主要分布在隧道中部,隧道渗漏水通道以螺栓孔为主。管片接缝错台是其他相关病害产生的直接原因。

Based on the disease investigation results of a large diameter river crossing shield tunnel in Nanjing Metro,the typical disease characteristics of interval tunnel were discussed,and the direct causes of some diseases were preliminarily discussed.The results showed that the typical diseases of the interval tunnel relied on mainly included deformation of segment joints,segment cracking,tunnel leakage,and internal structural cracking.The statistical results of segment joint misalignment within the interval met the normal distribution,and the value of lower measuring points were less than that of upper measuring points.The over limit rate of misalignment amount was less than 1%,and the misalignment amount of longitudinal joint of capping block was larger than other positions.Angle collapse had the largest proportion of segment damage.Bracket cracking was common in tunnels,and it had a certain correlation with the position of segment circumferential joint and prefabricated flue slab joint.The cracks of the middle partition wall were mainly distributed in the middle of the tunnel,and the leakage channel of the tunnel was mainly bolt holes.The dislocation of segment joints was the direct reason of the other related diseases.