隧道衬砌厚度对结构安全性及裂缝演化规律影响研究

Influence of Tunnel Lining Thickness on Structural Safety and Evolution Laws of Crack

以广西某高速公路隧道工程为背景,基于ABAQUS有限元分析软件建立三维数值模型,模拟研究衬砌厚度不足对衬砌结构安全性和裂缝演化规律的影响。结果表明:隧道衬砌厚度不足显著影响衬砌结构的安全性,减薄位置处安全系数随着内衬厚度的减小而减小;拱顶厚度不足时,对衬砌结构安全性的影响最大;衬砌减薄分散型分布对拱顶、拱肩处安全性影响较大;衬砌减薄集中型分布对边墙安全性影响较大。裂缝首先出现在减薄区域对应的衬砌内侧;随着内衬厚度的减小,裂缝数量增加、扩展速度加快,破坏提前;衬砌减薄集中型分布产生的裂缝面积大于分散型分布产生的裂缝面积。

Against the background of a expressway tunnel project in Guangxi,a 3D numerical model was constructed by the finite element analysis software ABAQUS to simulate and study the influence of insufficient lining thickness on the safety of lining structures and crack propagation laws.The results indicated that the insufficient thickness of tunnel linings would significantly affect the safety of lining structures,and the safety factors at thickness reduction thinning positions decreased with the decrease of the thickness.The insufficient thickness at the vault had a greatest impact on the safety of lining structures,the dispersive distribution of the lining thinning had a greater impact on the safety of the vault and arch shoulders,and the concentrated distribution of the lining thinning had a greater impact on the safety of side walls.Crack first appeared in the inside of linings corresponding to the lining thinning area.With the decrease of lining thickness,the number of cracks increased,the cracking speed increased,and destruction advanced simultaneously.The cracking area generated by the concentrated distribution of lining thinning was larger than that by the dispersed distribution.