深部-海底开采岩体损伤力学特性与破坏机理

It takes engineering rock mass in deep-undersea mining as the research subject, damage mechanics experiments and tests with different scale, confining pressure, load and unload,water and chemical reaction, seepage velocity and dynamic load will be carried out based on complex engineering geological and hydrogeological environment of high stress, transient unload, high pressure seepage and chemical corrosion of bedrock brine, and high frequency blasting disturbance. . The damage and weakening effects of physico-chemical and mechanical parameters, the failure mode of crack initiation, propagation, connection and coalescence of rock mass will be obtained. The strain-energy density function, damage tensor, permeability tensor and initial crack strength criteria expressions of rock mass equivalent damage will be deduced to establish chemical damage and weakening mechanics model and strength criterion of rock mass in the effect of bedrock brines, water and different chemical solutions with different flow pressure and velocity.. The transformation mechanisms of stress adjustment and transfer, energy aggregation, storage, transfer and release in rock under different coupled static-dynamic load and unload will be studied to reveal fracturing mechanism and nonlinear cumulative characteristics and to establish critical perturbation mechanism, catastrophe model and theoretical mechanics criteria of rock mass failure in the effect of high stress, transient unload and high frequency blasting disturbance. . The damage mechanics model under mechanical-hydrological-chemical-disturbed coupling of rock mass in deep-undersea mining will be established, and quantification parameters of coupling strength will be deduced to reveal the damage and failure mechanism of rock mass and its dynamic evolution characteristics which will lay the theoretic foundation for dynamic disaster temporal and spatial prediction in deep-undersea mining.

以深部-海底开采工程岩体为研究对象，基于高应力、强卸载、基岩卤水高压渗流与化学侵蚀及爆破扰动等复杂工程与水文地质环境，通过不同(尺度-围压-加卸载-水化学作用-渗流-动载扰动)模式岩石(体)损伤力学实验与测试，得到岩石物化、力学参数损伤劣化效应与裂纹萌生-扩展-贯通破坏模式，推导不同水化学溶液作用下岩体等效损伤应变能密度函数、损伤张量与渗透张量演化方程及初始裂纹强度判别表达式；研究不同加卸载模式下岩石内部应力调整→转移、能量聚集→存储→传递→释放转化机制，建立高应力强卸载与爆破扰动岩体疲劳损伤碎裂机理及非线性累积特性，推导岩体破坏的临界微扰机制、突变模型与力学判据；建立深部-海底开采多场耦合岩体损伤力学模型，推导耦合强度量化参数；揭示深部-海底开采岩体损伤破坏机理及动力学演化特征，为深部-海底开采岩体动力灾害时空预报奠定理论基础。

本项目以深部-海底开采工程岩体，综合考虑高应力、渗流、化学腐蚀及开采扰动等复杂工程及水文地质条件，通过多场耦合作用下采动岩体损伤本构模型及破裂过程的渗流-应力耦合特征、岩石损伤破裂演化模型及强度劣化影响、复杂应力条件下岩石岩爆倾向性及深部开采岩爆预紧控制技术等系统研究，探讨了深部-海底开采岩体损伤破坏机理及动力学演化特征，为深部-海底开采岩体动力灾害时空预报奠定理论基础。项目取得以下创新性研究成果：.（1）通过不同酸性、流速水化学溶液作用后的花岗岩岩石力学试验，量化分析了水化学溶液作用下花岗岩主要力学参数的损伤劣化规律，建立了自然状态和水化学溶液作用下裂隙岩石的损伤变量演化方程与本构模型，揭示了深部-海底开采岩体损伤破坏机理及动力学演化特征。.（2）从埋深、水压力、应力、尺寸效应等方面分析了采动损伤岩体渗流特性；引入“表征单元体”的概念，建立了反映岩体非均匀性和各项异性的三维渗流-应力场耦合的数学模型，推导了采动岩体损伤破裂后的本构方程、损伤张量和渗透张量演化方程及多场耦合强度量化参数表达式。.（3）利用FLAC3D软件对矿区深部矿体开采、巷道开拓进行考虑酸性高矿化度地下水对岩体侵蚀效应的流固耦合数值计算，研究深部生产活动的应力场、位移场分布特征，为实现矿山安全高效生产的目标提供保障。.（4）基于颗粒流（PFC）理论，运用PFC兼容的FISH语言编译了岩石非均质几何程序。构建了岩石单轴和三轴压缩试验的非均质几何模型，研究了荷载作用下岩石疲劳损伤破坏机理、非线性累积特性和规律，以及相应的岩石力学参数损伤弱化效应。.（5）总结循环加卸载条件下岩石内部能量的聚集→存储→传递→释放转化机制、裂隙损伤应力演化过程及基本力学参数的演化规律，分析了不同加卸载条件下岩石的岩爆倾向性指标。.（6）揭示开挖前后巷道围岩能量聚集、转移和耗散规律，获得三山岛金矿深井开挖扰动后围岩能量场的分布特征，对巷道围岩内可能发生岩爆区域的空间分布进行预测，建立相应的深部-海底采动岩体岩爆预报和灾害时空预警系统并提出有效的主动防控措施。