非稳态渗压诱导岩体破裂时空演化及定量表征方法研究

The unstable seepage pressure (USP) can induce fast propagation of rock fracture, followed by nucleation, and eventually transfixion failure of rock mass. The evolutive process and the parameters for the evolution of rock fracture are difficult to be evaluated, making it rather challenging to quantitatively predict the happening of rock water-bursting disasters. By utilizing several advanced techniques, such as three-dimensional (3D) Reconstruction, etc., this project is intended to study the characteristics of the space-time evolution of rock fracture. To achieve this objective, an experimental programme has been planned to be implemented. In the experimental programme, the transparent rock specimens incorporated with the natural fractures will be printed using a 3D printer, and the USP is going to be generated by adopting pulse stresses to motivate the flow of the tracer particles-marked fluid. The factors of rock fracture induced by the USP will be recognized and extracted. The 3D reconstruction method is going to be developed. The expanding of the rock fracture induced by the USP that is produced by the dynamic stress field is about to be numerically simulated. The quantitative correlations of the key parameters characterizing the spatial expanding of the rock fracture will be clarified. Based on the time-space evolution characteristics and the energy criterion, an analytical function for the time-space evolution parameters of the dynamic stress field, seepage pressure field, and rock fracture factors is about to be established. A strength criterion for the determination of the rock fracture caused by the USP that is produced by the dynamic stress will be proposed. The mechanisms accounting for the expanding of the USP induced rock fracture are going to be discussed respectively on macroscopic, mesoscopic, and microcosmic scales. An approach to visualizing and quantitatively characterizing the time-space evolution of the USP induced rock fracture will be finally derived. Additionally, the field testing results are going to be adopted to challenge and modify the proposed theoretical models. The modified models are expected to provide some valuable decision-making references for the prediction, evaluation, and control of the rock disasters caused by unstable seepage pressure.

非稳态渗压诱导岩体裂隙快速扩展、成核直至破坏，其断裂演变参数及过程难以厘定，造成岩体突水灾害定量化推断十分困难。本项目利用脉冲应力驱动示踪粒子流体形成非稳态渗压，进行诱导3D打印生成的透明裂隙模型断裂时空演化规律的实验研究；拟通过图像处理技术分析表面三维变形及应变、粒子流场分布及流动特性，进行非稳态渗压下岩体损伤断裂因子辨识与提取；发展数值重构方法，模拟动应力场引起非稳态渗流诱导裂隙扩展过程；基于时空演化规律和能量准则，建立动应力场、渗压场及断裂因子之间时空效应参数的解析函数，提出损伤断裂强度准则，探讨非稳态渗压诱导岩体裂隙扩展过程的宏细微观破损机理，形成时空演化过程的可视化与定量表征方法；结合现场试验，验证和优化模型，为岩体动渗灾害预测、评估与控制提供科学参考。

地下水丰富的地区，由于施工扰动引起的非稳态渗压诱导岩体裂隙快速扩展、成核直至破坏，其断裂演变参数及过程复杂，造成施工过程中岩体突水灾害定量化推断十分困难。本项目利用自主研发的岩溶塌陷模拟装置，实现了脉冲应力驱动示踪粒子流体形成非稳态渗压，进行断裂时空演化规律的实验研究；通过图像处理技术分析表面三维变形及应变、粒子流场分布及流动特性，进行了非稳态渗压下岩体损伤断裂因子辨识与提取；发展数值重构方法，模拟了动应力场引起非稳态渗流诱导裂隙扩展过程；基于时空演化规律和能量准则，进行了动应力场、 渗压场及断裂因子之间参数敏感性分析，提出了损伤断裂强度准则，探讨了非稳态渗压诱导岩体裂隙扩展过程的宏细微观破损机理，形成实验定量表征方法；结合合肥天鹅湖隧道和苏州环秀湖隧道进行了现场试验，结果表明方法可行，为岩体动渗灾害预测、评估与控制提供科学参考。按照研究计划完成了物理实验，理论计算，数值模型和工程应用，达到了预期研究目标。研究成果超过了研究计划书中预期目标，实际完成“论文 31 篇，其中28 篇发表在国际高水平期刊并被 SCI或EI数据库检索；申报发明专利 9项，已授权发明专利4 项，其中关于“一种基于地层弱化的岩溶塌陷模拟实验装置及方法”的授权发明专利正在评估转让；2名研究生获得国家奖学金。课题组成员参与国内、国际学术性会议 10余次，主持人作为大会特邀报告出席中科院百人论坛 1 次。课题培养 10名硕士研究生；获得湖南省自然科学奖二等奖1项，浙江省岩土力学与工程学会自然科学奖特等奖1项，安徽省交通科技进步奖5项”。