单轴加载下非均匀含水泥质粉砂岩破裂演化模拟研究  

SIMULATION STUDY ON THE FRACTURE EVOLUTION OF HETEROGENEOUS WATER-CONTENT ARGILLACEOUS SILTSTONE UNDER UNIAXIAL LOADING

作　　者：张磊[1] 周剑 武艳芳[3,4] 张路青 李晓[3,4] 彭潇[1] ZHANG Lei;ZHOU Jian;WU Yanfang;ZHANG Luqing;LI Xiao;PENG Xiao(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Institute of Earth Sciences,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]北京工业大学建筑工程学院,北京100124 [2]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [3]中国科学院地质与地球物理研究所,中国科学院页岩气与地质工程重点实验室,北京100029 [4]中国科学院地球科学研究院,北京100029

出　　处：《工程地质学报》2024年第6期2210-2227,共18页Journal of Engineering Geology

基　　金：国家自然科学基金项目(资助号:42277144,41972287)。

摘　　要：粉砂岩作为地球上广泛存在的岩石之一,在工程中经常被用到。泥质粉砂岩中含水量的增加会致使其强度降低和变形增加,从而导致洞室坍塌、边坡失稳等地质灾害。因此研究不同含水率下泥质粉砂岩破裂演化规律十分重要。本研究以龙游石窟围岩泥质粉砂岩为研究对象构建数值模型,基于实验室在位加载高能CT实时扫描试验获得的应力-应变曲线和裂纹形态修正模型参数,模拟不同含水率泥质粉砂岩在单轴压缩试验中的动态破裂演化过程,并通过声发射和矩张量反演技术来揭示不同含水率对泥质粉砂岩破裂的影响规律。研究结果表明:(1)从泥质粉砂岩强度方面,随着含水率的提高,泥质粉砂岩的强度逐渐降低,当含水率超过50%时,水对泥质粉砂岩强度弱化效应减弱;(2)从AE震级和b值大小方面,随着含水率的增加,试样破坏时的b值逐渐增加,这说明含水率的增加会使得泥质粉砂岩破裂过程产生的小事件数目增多,破坏渐进性增强,剧烈程度减弱,破坏释放的能量降低;(3)从破裂形态和AE失效源方面,随含水率的增加,AE剪切失效源的占比逐渐增加,泥质粉砂岩破坏模式由单斜面剪切破坏演变至Ⅹ状共轭斜面剪切破坏,含水率进一步增加趋近饱和状态,泥质粉砂岩的破坏表现为劈裂主导的外侧表皮剥落与内部剪切破坏。Siltstone,as one of the most widely distributed rock types on Earth,is frequently used in engineering projects.The increase in water content within argillaceous siltstone can lead to reduced rock strength and increased deformation,which in turn may result in geological hazards such as tunnel collapses and slope landslides.Therefore,understanding the fracture evolution of argillaceous siltstone under different water contents is significant.This study focuses on constructing a numerical model of the argillaceous siltstone surrounding the Longyou Grottoes.Using stress-strain curves and fracture morphology obtained from high-energy CT real-time scanning experiments under in situ loading conditions,the model parameters were calibrated.The dynamic fracture evolution process of argillaceous siltstone with varying water content under uniaxial compression was then simulated.Furthermore,the study uses acoustic emission and moment tensor inversion techniques to reveal the effects of different water contents on the fracture behavior of argillaceous siltstone.The research results indicate the following:(1)In terms of Argillaceous Siltstone Strength:As water content increases,the strength of argillaceous siltstone gradually decreases.However,once the water content surpasses 50%,the weakening effect of water on argillaceous siltstone strength diminishes.(2)In terms of AE Magnitude and b-value:With increasing water content,the b-value at failure also increases.This suggests that higher water content leads to a greater number of small-scale events during the fracture process,making the failure more gradual,less severe,and releasing less energy.(3)In terms of Fracture Morphology and AE Failure Sources:As water content rises,the proportion of AE shear failure sources gradually increases.The failure mode of the argillaceous siltstone transitions from single-plane shear failure to X-shaped conjugate shear failure.As the water content approaches saturation,the failure behavior is characterized by splitting-dominated exfoliation of the

关 键 词：龙游石窟泥质粉砂岩 岩石含水率 声发射技术 矩张量反演技术 CT测试试验 裂纹模式 

分 类 号：P642.3[天文地球—工程地质学]