基于波电场特性的周期性饱水砂岩损伤演化机理研究

The damage and deterioration of rock was caused constantly with the periodic interaction between water and rock on inland port engineering construction, which can affect the stability and security of the structure, While the statics method has some limitations. So the study focus on the periodic saturated sandstone of Chongqing port area, by the method of Wave test and resistivity test that is a key technology, for researching the damage evolution of periodic saturated sandstone. Using theoretical analysis, laboratory experiments, numerical simulation signal processing and other ways of combining methods to study the science problem, such as deterioration characters of periodic saturated sandstone, the influence mechanism of wave field characteristics on microstructure deformation of periodic saturated sandstone, the correlation between stress and wave field characteristic parameters. The deterioration characters of periodic saturated sandstone will be clarified, the characterization methods of wave field characteristic parameters of damage on periodic saturated sandstone will be established, the damage evolution model will be built based on the parameters of coupled wave-electronic filed, and the failure criteria will be provided. The study provides a research tracks in theory, which has innovative and multi-discipline, for damage identification and stability evaluation of engineering rock mass. The results give some science support for long-term stability evaluation of engineering rockmass in practice.

内河港口工程建设中，周期性水岩相互作用不断引起承载岩石的劣化损伤，严重影响结构的稳定性和安全，而静力学方法难以实施评价。鉴于此，本项目以重庆港区典型的周期性饱水砂岩作为研究对象，以波动测试和电阻率测试方法作为关键技术手段，研究周期性饱水砂岩的损伤演化。综合采用理论分析、试验分析、信号处理、数值模拟等多种研究方法，针对周期性饱水砂岩的劣化特性、周期性饱水砂岩微观结构变形对波电场特性的影响机制、周期性饱水砂岩的波电场特征参数与应力应变的相关性等关键科学问题开展研究，预期能够阐明周期性饱水砂岩的微观变形机制及宏观力学特性的劣化规律，建立周期性饱水砂岩损伤的波电场特征参数表征方法，构建基于波电场参数耦合的周期性饱水砂岩损伤演化模型，并提出相应的破坏判别准则。项目的研究从理论上为工程岩体的损伤识别及稳定性评价提供了具有创新性和多学科交叉的研究思路，研究成果可为港区工程岩体长期稳定性评价提供科学支撑。

内河港口工程建设中，周期性水岩相互作用不断引起承载岩石的劣化损伤，严重影响结构的稳定性和安全，而静力学方法难以实施评价。鉴于此，本项目选取重庆港区典型的周期性饱水砂岩作为研究对象，筛选了20组（120个）砂岩圆柱体试件，开展了不同循环周期的间歇饱水试验，测试了砂岩试件的细观结构参数、基本物理力学指标、声波参数、电阻率参数，研究了周期性饱水作用下砂岩宏观物理力学参数和细观结构的变化规律，揭示了周期性饱水作用下砂岩的劣化特性，建立了周期性饱水作用下砂岩声波参数和电阻率参数与基本物理力学参数之间的相关性，在此基础上构建了基于波速、衰减系数、非线性系数和电阻率等不同参数的损伤表征方法，并采用不同损伤变量分析了周期性饱水作用下砂岩的损伤演化过程。结果表明：周期饱水作用下的砂岩试件，在低循环周期，内部结构在水-岩作用下发展迅速导致损伤渐进性较强，在高循环周期，内部结构逐渐趋于稳定，不同损伤变量对周期性饱水作用下砂岩的损伤敏感程度是不同的，表现为非线性系数>波速>电阻率>衰减系数。项目的研究从理论上为工程岩体的损伤识别及稳定性评价提供了具有创新性和多学科交叉的研究思路。