基于工程体-地质体相互作用的接触面变形破坏研究

RESEARCH ON DEFORMATION AND FAILURE OF INTERFACE BASED ON INTERACTION BETWEEN STRUCTURAL BODY AND GEO-BODY

针对工程体与地质体的相互作用机制,研究工程体和地质体之间不规则接触面的性质和表征方法;提出立方体覆盖的新方法来直接测量表面分维,提高了测量精度。利用光贴片试验研究不同接触形态地质体与工程体共同作用的界面效应(界面的变形、破坏和滑移规律)。开发了具有非均匀性和分形特性的接触面单元,建立了具有接触面特性的两体(工程体与地质体)力学模型。研究碾压混凝土坝和岩基两体相互作用的破坏模式和影响因素,以客观评价大坝整体的稳定性问题。应用断裂力学研究碾压混凝土坝和坝基两体相互作用时不规则坝踵裂缝扩展的稳定性,获得了裂缝扩展的临界长度和荷载,研究结果表明:两体接触面的粗糙性阻碍了裂缝的扩展。

Based on the mechanism of the interaction between geo-body and structural body, the nature and description method of irregular interface between geo-body and structural body are studied. A new cubic covering method is proposed to determine the fractal dimensions of the interface, which improves the measuring precision. The interface effects, such as the deformation, failure and slide of interface, are discussed for different interface shapes by using the photoelastic coating tests. The two-body（geo-body and structural body） mechanical model with the interface effect is established. The interface element with homogeneity and fractal distribution is developed in numerical simulation. The failure pattern and influential factors are studied based on the interaction between gravity dam and foundation, which objectively estimates the global stability of the dam. The propagation pattern of the irregular interface cracks at heel of concrete gravity dam is studied by using fracture mechanics. Critical length and loads of interface crack propagation are obtained using composite fracture criteria. The results indicate that the coarse interface prevents the propagation of interface crack, and redounds to stability of gravity dam.