水压和变形下嵌缝材料设计及黏接层破坏机理研究

水工建筑物伸缩缝的破坏及渗漏问题会直接影响水工结构自身的安全稳定。本文基于南水北调穿黄隧洞工程实际背景,引入基于内聚力(Cohesive Zone Model)单元界面破坏有限元模型,进行了伸缩缝嵌缝材料在背水压作用下的仿真分析,并将其结果与室内压水试验的应变-荷载数据进行对比,给出了适合于聚脲基复合防渗体系嵌缝内聚力单元的断裂能。同时,分析计算了伸缩缝宽度及嵌缝深度对结构抵抗水压能力的影响,证明所取参数的正确性。进一步分析了伸缩缝变形和水压力作用条件下的仿真结果,给出了伸缩缝变形、伸缩缝宽度、嵌缝深度及承载能力之间的关系。本文结果可为伸缩缝的结构设计提供指导。

Study on the design of joint sealing material and failure mechanism of adhesive layer under water pressure and deformation

The damage and leakage of contraction joint in hydraulic structure will impact the safety of the structure. In this work, the authorsintroduce Cohesive Zone Model (CZM) into Finite Element Model (FEM) to simulate the damage process of joint sealing material under water pressure and deformation based on the tunnel across Yellow River on middle route of the South-north Water Transfer Project. We compare the results from simulation analysis with the strain-pressure curve from indoor pump-in test, and propose the fracture energy of CZM which fitted to bonding layer of joint sealing material. Furthermore, the impact of the width of contraction joint and the depth of joint sealing material on ability of resist to water pressure are discussed, which prove the validity of parameters. We also analyze the relation among contraction joint deformation,width of contraction joint,depth of joint sealing material and carrying capaci-ty under the situation that the system bearing deformation and water pressure. The results provide theoreti-cal foundation for physical mechanics design of joint sealing material and guidance for structure design of contraction joint.