【摘要】 针对复杂地质条件隧道二衬结构在多因素作用下的开裂损伤,以龙塘隧道左洞二衬开裂为研究背景,通过分析左洞ZK58+795断面的变形监测数据并进行有限元数值模拟,结合理论与实测数据得到如下结论:隧道左洞围岩塑性圈厚度约2m,左洞二次衬砌所受的最大弯矩(1.159 73tonf·m)(1tonf=10kN)出现于拱顶位置,最大轴力(1 118.690tonf)出现于左侧拱腰.出洞口段地形和地质条件的不对称使得支护结构在偏压荷载作用下产生局部应力集中,致使衬砌实际应力超过允许强度,是隧道衬砌开裂的主因,而施工过程中混凝土捣实质量欠缺与后期保养不力也为开裂提供了生长条件,最终造成龙塘隧道左洞二衬混凝土受拉屈服破坏.更多还原

【Abstract】 Considering the second lining of tunnel in the complex geological conditions cracks and damages under the influence of various factors,we used the second lining of Long Tang left hole as the research background.According to the monitoring data of Long Tang left hole section ZK58+795and the numerical analysis model by the finite element software.we got the following conclusions through the theory and the measured data.The plastic ring’s thickness of Long Tang left hole is about 2m,maximum bending moment and axial force of the second lining appeared in the top position(1.159 73tonf·m)and left arch waist(1 118.690tonf)respectively.Asymmetric terrain and geological conditions of tunnel outlet caused local stress concentration in the support under bias load.It made the stress bigger than strength.So asymmetric terrain and geological conditions are the main causes of the cracking of tunnel lining.The poor quality of the lining concrete and the inadequate maintenance of the later period,also provided the necessary condition for cracking.Eventually caused the second lining of Long Tang left hole yielded in tension and destroyed.更多还原