层状复合岩的能量演化及破坏特征模拟研究  

Simulation Study on Energy Evolution and Failure Characteristics of Layered Composite Rock

作　　者：胡量 肖桃李[1] 折海成 赵云峰 郑远龙 HU Liang;XIAO Taoli;SHE Haicheng;ZHAO Yunfeng;ZHENG Yuanlong(School of Urban Construction,Yangtze University,Jingzhou,Hubei 434023,China;The Key Laboratory of Well Stability and Fluid&Rock Mechanics in Oil and Gas Reservoir of Shaanxi Province,Xi'an,Shaanxi 710065,China;Zhuhai Construction Engineering Group,Zhuhai,Guangdong 519085,China)

机构地区：[1]长江大学城市建设学院,湖北荆州市434023 [2]陕西省油气井及储层渗流与岩石力学重点实验室,陕西西安710065 [3]珠海建工控股集团有限公司,广东珠海市519085

出　　处：《矿业研究与开发》2025年第2期184-194,共11页Mining Research and Development

基　　金：国家自然科学基金资助项目(52204201);油气钻采工程湖北省重点实验室开放基金项目(YQZC202204);水利部水库大坝安全重点实验室开发研究基金项目(YK323003)。

摘　　要：在岩土工程中,失稳破坏常会同时发生于多层岩体内,其不同的组合方式、岩性等因素均会影响裂纹的发展趋势。研究采用离散元PFC2D软件建立试样模型,并模拟单轴压缩试验揭示软硬岩层占比对岩样力学性质、破坏特征及能量演化规律的影响。研究表明:(1)层状复合岩样中的硬岩部分占比是影响岩样峰值强度的主要因素,随着硬岩部分占比增大,岩样的峰值应力逐渐增大;(2)层状复合岩样的微裂纹数及输入总应变能均在相邻岩层厚度比(R)最小时取得最小值,表明R的减小会导致岩样破坏的提前发生;(3)在层状复合岩样的能量分析中引入弹性能耗比K,并验证了K值的增大可以作为岩石发生变形破坏的预警信号;(4)层状复合岩样的主要破坏模式为张拉-剪切混合破坏,宏观裂纹基本起裂于软岩部分,而后由于软岩部分横向应变的急剧增大,裂纹向硬岩部分贯通,揭示岩样的破坏是一个逐步丧失承载力的过程。研究成果可为实际工程提供参考。In geotechnical engineering,instability failure often occurs in multi-layer rock mass at the same time,and its different combinations,lithology and other factors will affect the development trend of cracks.The discrete element PFC2D software was used to establish the sample model,and the uniaxial compression experiment was simulated to reveal the influence of the proportion of soft and hard rock strata on the mechanical properties,failure characteristics and energy evolution law of rock samples.The results are drawn as follows.Firstly,the proportion of hard rock in the layered composite rock sample is the main factor affecting the peak strength of the rock sample.As the proportion of hard rock increases,the peak stress of the rock sample gradually increases.Secondly,the number of microcracks and the total input strain energy of the layered composite rock sample are the minimum when the thickness ratio(R)of the adjacent rock layer is the smallest,indicating that the decrease of R will lead to the early failure of the rock sample.Thirdly,the elastic energy consumption ratio K is introduced into the energy analysis of layered composite rock samples,and it is verified that the increase of K value would be used as an early warning signal for rock deformation and failure.Fourthly,the main failure mode of the layered composite rock sample is tension-shear mixed failure,and the macroscopic cracks generally originate in soft rock part.Then,due to the sharp increase of the transverse strain of the soft rock part,the cracks penetrate into the hard rock part,revealing that the failure of the rock sample is a process of gradual loss of bearing capacity.The research results can provide a reference for practical engineering.

关 键 词：层状复合类岩石 数值模拟 破坏特征 能量演化 弹性能耗比 

分 类 号：TD325[矿业工程—矿井建设] TU45[建筑科学—岩土工程]