三峡库区灰岩浸泡损伤-孔隙水压耦合模型研究  

Study on the coupled model of limestone soaking damage and pore water pressure in the Three Gorges Reservoir Area

作　　者：段国勇 马如梦 DUAN Guoyong;MA Rumeng(Key Laboratory of Geological Hazards in the Three Gorges Reservoir Area,Ministry of Education(Three Gorges University),Yichang 443002,Hubei,China;College of Electrical Engineering and New Energy,Three Gorges University,Yichang 443002,Hubei,China;Hubei Provincial Key Laboratory for Disaster Prevention and Reduction(Three Gorges University),Yichang 443002,Hubei,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),湖北宜昌443002 [2]三峡大学电气与新能源学院,湖北宜昌443002 [3]防灾减灾湖北省重点实验室(三峡大学),湖北宜昌443002

出　　处：《水利水电技术（中英文）》2024年第9期178-186,共9页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金(U2034203);防灾减灾湖北省重点实验室(三峡大学)开放基金(2022KJZ08)。

摘　　要：【目的】自2003年开始蓄水以来,三峡库区水库地震的数量达到上万次,对比蓄水前后的地震数据变化可以看出,库水浸泡作用明显改变了水库地震区域灰岩的力学特性。为了研究长期库水浸泡作用对库区灰岩力学特性的影响,【方法】针对库区蓄水环境,开展了不同浸泡时长和不同孔隙水压对灰岩三轴压缩强度的影响试验,以及浸泡作用下灰岩孔隙率变化的电镜扫描分析。【结果】试验结果显示:在浸泡作用和三轴试验中考虑不同孔隙水压时,灰岩的三轴抗压强度呈现出短期浸泡时的强度增强现象,与一些水岩相互作用理论存在差异。基于这些差异,从宏观力学特性和微观结构的角度分析了灰岩损伤发展规律,提出了灰岩浸泡损伤-孔隙水压耦合模型,估算了在试验条件下使溶孔产生破裂的孔隙压力临界值,按照静水压力取孔隙压力值为地下5.6 km处,与三峡库区高桥断裂区域的水库地震震源深度较为吻合。【结论】水库地震区域灰岩的损伤并非单一的浸泡损伤,是耦合了孔隙率演变、孔隙压力变化、孔隙水形态演化等一系列复杂现象的破坏失效过程。研究成果可为水利工程中诱发地震的机理研究提供一定的理论参考价值。[Objective]Since the start of water storage in 2003,the number of earthquakes in the Three Gorges Reservoir area has reached tens of thousands.Comparing the changes in seismic data before and after water storage,it can be seen that the soaking effect of reservoir water has significantly changed the mechanical properties of limestone in the seismic area of the reservoir. In orderto study the influence of long-term reservoir water immersion on the mechanical properties of limestone in the reservoir area,[Methods]This article focuses on the water storage environment in the reservoir area and conducts experiments on the influence ofdifferent soaking times and pore water pressure on the triaxial compressive strength of limestone, as well as electron microscopyscanning analysis of the changes in limestone porosity under soaking. [Results]The experimental result showed that when differentpore water pressures were considered in the immersion and triaxial tests, the triaxial compressive strength of limestone showeda strength enhancement phenomenon during short-term immersion, There are differences with some theories of water rock interaction.Based on these differences, this article analyzes the development law of limestone damage from the perspectives of macroscopicmechanical properties and microstructure, and proposes a coupling model of limestone soak damage-pore water pressurecoupling model. The critical value of pore pressure that causes dissolution pores to rupture under experimental conditions wasestimated, and the pore pressure value was taken as 5. 6 km underground based on static water pressure, which is in good agreementwith the depth of the reservoir earthquake source in the Gaoqiao fault area of the Three Gorges Reservoir area. [Conclusion]The damage of limestone in the reservoir water earthquake area is not a single soaking damage, but a failure process thatcouples a series of complex phenomena such as porosity evolution, pore pressure change, and pore water morphology evolution.The research method in this ar

关 键 词：水库地震 灰岩 浸泡损伤-孔隙水压耦合模型 力学性能 三峡水库库区 水利工程 

分 类 号：TU42[建筑科学—岩土工程]