高应力脆性岩石卸荷条件下时滞性破坏机制

项目名称： 高应力脆性岩石卸荷条件下时滞性破坏机制

项目编号： No.51209020

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 水利科学与海洋工程学科

项目作者： 汪斌

作者单位： 长江水利委员会长江科学院

项目金额： 25万元

中文摘要： 深埋地下脆性岩体开挖卸荷诱发的重大工程灾变往往不是开挖瞬时发生的，有时表现出滞后效应。本课题依托西南水电站的建设，通过室内试验、理论研究及细观力学数值试验，对深埋脆性岩石在加、卸载路径下的时滞性破裂机制及其强度的时效特性等岩石力学前沿问题展开深入细致的研究，通过不同应力强度因子（偏应力强度比）下的岩石三轴静疲劳试验并匹配微裂纹孕育、扩展等过程的AE声发射活动监测，揭示加、卸应力路径下岩石强度及微裂隙的时效演化特征和规律，建立岩石滞后破坏所需时间与应力强度因子之间的函数关系，进而提炼脆性岩石时滞性破裂及强度时效性机制；通过在PFC颗粒接触本构模型中引入微裂纹损伤速率方程，重构并建立相应的应力腐蚀时效模型，从而提出基于颗粒流的脆性岩石滞后破坏时间及过程的模拟方法，初步形成一套地下深埋岩体开挖后围岩长期稳定性预测与评价的室内试验及细观力学数值模拟方法，具有重要的理论和工程应用价值。

中文关键词： 脆性岩石；声发射；高应力三轴卸荷；时滞性破坏试验；蠕变损伤模型

英文摘要： Some major engineering apocalypses indeuced by deep underground brittle rock excavation sometimes do not happen instantaneously, often show time-lag effect failure behavior. This research project based on the construction of Southwest hydropower station, through the laboratory test, theoretical research and micromechanics numerical experiments, the forefront rock mechanical issues such as time-lag failure mechanism of deep buried brittle rock in condition of loading and unloading path and time dependent characteristic of strength are researched in detailed. Via static fatigue testing on different deviatoritic stress intensity factor conditions, simultaneously monitoring the crack incubation and propagation matching AE testing, the time-dependent crack evolution regulation and characteristics are obtained and the functional relationships of lag time to failure vs. the deviatoric stress intensity factor are established, with above further research to refine the mechanism of time lag failure of rock. Through embedding in micro cracks damage rate equation to bonded-particle model in PFC, reconstructed and set up a corresponding stress corrosion aging model and to realize; Finally based on the particle flow code, the the simulation method of lag time to failure and the stress corrosion process are proposed. Hence a n

英文关键词： brittle rock；AE；tiraxial unloading test under high stress；Time-lag failure test；creep damage constitutive model