硬脆性岩石力学行为宏细观表征及围岩损伤强卸荷-温度耦合效应机制研究

The environment of hard brittle surrounding rock in the deep is different from shallow underground significantly. It is urgent to study the mechanical behavior and estimate the stability of the surrounding rock, which is a complicated scientific problem. The theme which this project will stick closely to is hard brittle feature of rock. Firstly, based on the analysis of rock mechanical behavior under brittle-ductile state, brittle-ductile index is proposed. Meanwhile, a three-dimensional strength criterion and an effective meso analytical method will be constructed to characterize the hard brittle rock. Then, laboratory and numerical tests of hard brittle rock will be conducted under strong-unloading, high temperature and heating-cooling conditions, respectively, which are facilitated by a monitoring and source localization method for complex medium in multi-field, to reveal the mechanism of hard brittle rock damage induced by multi-factor. Moreover, loading tests of hard brittle rock cubic sample containing hole will be conducted under room temperature and heating-cooling conditions. Macroscopic and mesoscopic mechanism of damage and fracturing near hole boundary under thermo-mechanical coupling will be uncovered, after which a new method for measuring the tensile strength will be probed. Finally, based on strong unloading-temperature synergistic mesoscopic model, mechanical properties and evolution of instability of hard brittle surrounding rock under different thermo-mechanical paths will be investigated. Research achievements will lay a theoretical foundation for the stability assessment and instability prediction of surrounding rock in deep drilling and nuclear waste storage projects. What’s more, research results can provide scientific reference for prediction and dynamic control of disasters including rockburst and pressure bump in mining and water conservancy projects.

深部硬脆性围岩赋存环境与浅部迥异，其力学行为及稳定性评价是亟需解决的科学难题。项目紧扣岩石硬脆性特征这一主题，首先针对岩石的脆延性力学行为，提出脆延性评价指标，构建符合硬脆性岩石特征的三维强度准则，建立有效表征岩石脆性力学特性的细观分析方法；其次，开展强卸荷、高温及高温-冷却作用下硬脆性岩石损伤演化室内及数值试验，开发多场复杂介质破裂监测定位方法，揭示硬脆性岩石损伤多因素诱发机理；通过常温及高温-冷却条件下硬脆性岩石含孔试样加载试验，揭示热-力耦合作用下硬脆性岩石孔洞边界损伤破裂宏细观机理，探索测定硬脆性岩石抗拉强度的方法；最后基于硬脆性岩石强卸荷与温度协同作用细观模型，探究不同热-力耦合路径下的硬脆性围岩力学特性及失稳孕育演化机制。研究成果可为深部钻井、核废料储存等工程围岩稳定性评估、失稳预测等奠定理论基础，同时可为矿山、水利等领域的岩爆、冲击地压灾害预测与动态调控提供科学参考。

深部硬脆性围岩赋存环境与浅部迥异，其力学行为及稳定性评价是亟需解决的科学难题。项目紧扣岩石硬脆性特征这一主题，首先针对硬脆性岩石在复杂应力条件下的力学行为，提出了一种基于新偏函数的修正Hoek-Brown岩石强度准则估计岩石三维强度，并建立了有效表征岩石脆性力学特性的细观分析方法；其次，开展强卸荷、高温及高温-冷却作用下岩石损伤演化室内及数值试验，揭示硬脆性岩石损伤多因素诱发宏细观机理；通过硬脆性岩石含孔试样的室内试验及数值试验，揭示了硬脆性岩石孔洞边界损伤破裂宏细观机理，并对岩石材料抗拉强度建议测试方法(巴西劈裂试验)提出了建议；最后，建立了一套完整的室内试验主/被动超声技术，并开发了多种声发射震源定位方法，可定量表征岩石试样损伤的时空演化特性。研究成果可为深部钻井、核废料储存等工程围岩稳定性评估、失稳预测等奠定理论基础，同时可为矿山、水利等领域的岩爆、冲击地压灾害预测与动态调控提供科学参考。