三峡工程饱水花岗岩抗拉强度时效特性研究

结合三峡工程永久船闸高边坡岩体的工作实际，试验分析了饱水花岗岩在劈裂拉伸条件下的“荷载－位移－时间”蠕变关系及其拉强度与破坏的历时性和时效性，建立了与加载间隔时间或加载速率间的经验关系，论证了水对增强石抗拉强度时效性的不利影响。文中还探讨了岩石时效强度理论的形式，提出了包括岩石材料拉伸破坏的应力条件与时间条件及其相应的计算判据，并讨论了三轴受力状态下岩石破坏历时与破坏函数间的关系。

Time-dependent Effects on the Tensile Strength of Saturated Granite at Three Gorges Project

In combination with the practical working condition of high slopes ofpormanent ship lock at the Three Gorges Project of the Yangtze River in China,this paper conducted experiments and analyses to find out the load-displacement- time creep relationship and the time dependency of tensile strength and rupturefor the saturated Three Gorges granite under split tension, established theempirical relation between tensile strength and time interval of loading(or rate ofloading) and demonstrated the unfavorable influence of water on the decrement intensile strength with time for rocks. The paper also discussed the form of the time-dependent theory of tensile strength for rocks, put forward respectively thefailure criteria of stress and of time for rock materials under tension. The rockrupture related to time history and to failure function undor triaxial condition wasalso theoretically studied. For the stopped loading(loading by stages)condition, alinear damage accumulation model was applied to describe the time dependency ofrocks, and we obtained a general knowledge of the variation of tensile strength ofrocks with rupture time history. On the basis of laboratory tests, theabove - mentioncd theoretical analyses were carried out for the time - dependencyof the tonsile strength for this kind of brittle elasto-viscous granite. Empiricalregression curves and the upper and lower bound values for the time-dependenttensile strength were obtained respecitively.