甘肃某高速公路隧道二衬裂缝成因及整治技术研究

Study on causes and treatment technology of second lining crack in highway tunnels in Gansu

依托甘肃某高速公路8座隧道维修工程,以专项检测数据、现场调查及维修期间揭露的情况为依据,结合各个隧道的原设计、施工、运营、检测评估情况,采用排除法对隧道二次衬砌裂缝的成因进行了深入分析,指出衬砌产生裂缝的主因是隧底仰拱缺陷,其引发衬砌不均匀沉降,致使衬砌局部混凝土受拉产生裂缝,而衬砌背后脱空和厚度不足减小了衬砌刚度,引发应力集中效应进一步恶化了衬砌受力状态。以衬砌裂缝病害的发育情况和隧道质量缺陷(衬砌厚度、仰拱厚度)二者间的相关性情况为出发点,提出了针对衬砌裂缝产生原因的处治方案,取得了良好的维修效果。

Relying on the maintenance work of eight tunnels in a highway in Gansu,based on the special inspection data,on-site investigation and the conditions exposed during the maintenance,combined with the original design,construction,operation,inspection and assessment of each tunnel,the cause of crack of second lining in tunnel is analyzed by the exclusion method in depth.It is pointed out that the main cause of the crack in the lining is the tunnel bottom arching defect,which leads the uneven lining to cause the concrete of the lining to be cracked,and the void behind the lining and the insufficient thickness reduce the rigidity of the lining.The stress concentration effect causes the lining stress state to be further deteriorated.Based on the correlation between the development of the lining crack disease and the tunnel quality defects(lining thickness and thickness of the inverted arch),the treatment of the cause of lining crack is proposed.The program has achieved good maintenance results.