【作者】 孙钧； 胡玉银；

【Author】 SUN Jun,HU Yu-yin (Department of Geotechnical Engineering,Tongji University,Shanghai,200092)

【机构】 同济大学地下建筑与工程系；

【摘要】 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"蠕变关系及其抗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,论证了水对增强岩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,对于分级加载情况,引入了线性损伤累积理论来进行描述,得到了岩石时效抗拉强度随其破坏历时变化的一些规律性认识。更多还原

【Abstract】 In combination with the practical working condition of high slopes of permanent 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 rupture for the saturated Three Gorges granite under split tension,established the empirical relation between tensile strength and time interval of loading(or rate of loading) and demonstrated the unfavorable influence of water on the decrement in tensile strength with time for rocks.The paper also discussed the form of the time-dependent theory of tensile strength for rocks,put forward respectively the failure criteria of stress and of time for rock materials under tension.The rock rupture related to time history and to failure function under triaxial condition was also theoretically studied.For the stepped loading(loading by stages) condition,a linear damage accumulation model was applied to describe the time dependency of rocks,and we obtained a general knowledge of the variation of tensile strength of rocks with rupture time history.On the basis of laboratory tests,the above-mentioned theoretical analyses were carried out for the time-dependency of the tensile strength for this kind of brittle elasto-viscous granite.Empirical regression curves and the upper and lower bound values for the time-dependent tensile strength were obtained respecitively.更多还原