高压水道围岩非线性渗流-变形耦合特性及渗透稳定性控制

Water inrush geological accident in the high pressure tunnel is bottleneck problem that needs to be addressed urgently in the areas of pumped storage power station construction, and is also a fundamental subject in the field of rock mechanics. By laboratory tests, theoretical analysis, numerical simulation and engineering experience, the project intends to give an insight into the non-linear flow and deformation coupled characteristic and seepage stability control in surrounding rocks of concrete reinforced hydraulic tunnel under the condition of high water pressure. The critical Reynolds number model and a non-linear flow model will be presented with the consideration of the effect of the fracture deformation and surface geometries, then a high pressure packer test analytical model and a non-linear flow parameter model for the surrounding rocks under high water pressure will also be established, which can be able to capture the micro-macroscopic mechanism for non-linear flow and deformation coupled characteristic. Finally, a seepage stability control strategy and optimal design method will be presented accounting for the effects of high water pressure in surrounding rocks of high pressure tunnel. This study will provide an important theoretical contribution to the issue of coupled hydro-mechanical behaviors for the rockmass under high water pressure, and also provide important actual application value for disaster prevention in the high hydropower engineering in China.

高渗透压力引起的高压水道突透水地质灾害是制约抽水蓄能电站建设发展的瓶颈问题，也是当前我国岩石力学工程领域亟需解决的重大安全课题。本项目以抽水蓄能电站钢筋混凝土衬砌高压水道围岩为研究对象，以连续介质力学、渗流力学和热力学原理为基础，采用室内外试验、理论分析、数值模拟与工程经验相结合的综合研究方法，研究高压水道围岩非线性-变形耦合特性与渗透稳定控制，建立基于裂隙形貌参量的临界雷诺数模型，提出变形条件下裂隙非线性渗流理论模型，建立高渗压条件下岩体渗透特性解析模型，推荐工程地质岩组非线性渗流参数的合理取值方法，揭示高压水道围压非线性渗流与变形耦合特性的宏细观机制，提出考虑高渗透水压作用的高压水道围岩渗透稳定控制策略与优化设计方法。本项目成果对于研究高渗压条件下岩体水-力耦合问题具有重要的科学意义，对于增强我国大型水利水电工程深埋隧洞突透水灾害防治能力具有重要的应用价值。

高渗透压力引起的高压水道突透水地质灾害是制约抽水蓄能电站建设发展的瓶颈问题，也是当前我国岩石力学工程领域亟需解决的重大安全课题。本项目以抽水蓄能电站钢筋混凝土衬砌高压水道围岩为研究对象，以连续介质力学、渗流力学和热力学原理为基础，采用室内外试验、理论分析、数值模拟与工程经验相结合的综合研究方法，研究高压水道围岩非线性渗流-变形耦合特性与渗透稳定控制，推导了表征法向压缩过程中裂隙力学开度分布演化的截断高斯分布函数，进而给出了法向荷载作用下裂隙水力开度eh和临界雷诺数Rec的计算模型。基于钻孔高压压水试验、钻孔录像和声波检测数据，提出了高压压水试验Q-P曲线的分段分类方法；基于非线性Izbash定律提出了高渗压下岩体渗透特性的解析模型，在此基础上推荐了高压压水试验过程中不同阶段渗透系数的估算方法。在此基础上，采用非达西定律、Signorini型变分不等式和自适应罚函数相结合的方法，推导了非达西渗流控制方程组及其有限元计算格式，并成功应用于广东阳江抽水蓄能电站高压岔管区内水外渗与围岩渗透稳定性评估。本项目成果对于研究高渗压条件下岩体水-力耦合问题具有重要的科学意义，对于增强我国大型水利水电工程深埋隧洞突透水灾害防治能力具有重要的应用价值。