重庆大学煤矿灾害动力学与控制全国重点实验室;重庆大学资源与安全学院;
为深入研究非均质矿物晶体微观结构影响下裂隙花岗岩的力学特性和损伤演化规律,结合花岗岩力学试验结果,开发了考虑矿物晶体结构影响的离散元数值模型,通过开展不同围压下裂隙花岗岩压缩试验,建立了围压和裂隙倾角双重因素影响下花岗岩应力峰值经验模型,从微观尺度上阐明了花岗岩微裂纹破裂机理。研究结果表明:(1)随裂隙倾角的增加,花岗岩抗压强度呈先降低后升高的趋势,在无围压条件下,裂隙倾角θ=31.8°时花岗岩的抗压强度最低。(2)应力加载过程中,花岗岩微裂纹演化呈空间局部化,沿晶张拉裂纹随机分布在试样内部,穿晶张拉裂纹则主要聚集在裂纹扩展阶段的断面附近,并伴随着宏观断裂。(3)随着围压的增大,总微裂纹数量逐渐增加,穿晶张拉裂纹在总微裂纹中的占比明显上升,围压为0, 10, 20和30 MPa时,穿晶张拉裂纹分别占总数的36.1%, 45.0%, 48.3%和51.4%。(4)非均质裂隙花岗岩强度特征受矿物基质空间分布的影响,正长石会阻止微裂纹的扩展和聚合。与单一剪切断面花岗岩相比,非均质性影响下“V”形宏观裂纹的花岗岩应力峰值更高。
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下载次数 | 被引频次 | 阅读次数 |
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基本信息:
DOI:10.13532/j.jmsce.cn10-1638/td.2024.04.005
中图分类号:TD315
引用信息:
[1]严旭锋,张振宇,郝胜鹏等.基于矿物晶体模型的非均质裂隙花岗岩双轴压缩微裂纹演化特征[J].采矿与岩层控制工程学报,2024,6(04):102-114.DOI:10.13532/j.jmsce.cn10-1638/td.2024.04.005.
基金信息:
重庆市杰出青年科学基金资助项目(CSTB2023NSCQ-JQX0075)