基于XFEM的双裂隙岩体冻胀裂纹扩展数值模拟研究  

Numerical simulation on crack propagation of frozen double-fractured rock by XFEM

作　　者：牛帅帅 罗学东[1] 周盛涛 蒋楠[1] NIU Shuaishuai;LUO Xuedong;ZHOU Shengtao;JIANG Nan(Faculty of Engineering, China University of Geosciences, Wuhan 430074, China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《合肥工业大学学报（自然科学版）》2022年第1期73-80,共8页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(41572281)。

摘　　要：为研究冻胀荷载对双裂隙岩体裂纹扩展及贯通机制的影响,文章基于扩展有限元法(extended finite element method,XFEM),分析冻胀力作用下不同岩桥参数双裂隙试样的裂纹扩展特征和破坏形式,探究在冻胀力和侧向卸荷共同作用下双裂隙试样的裂纹扩展贯通规律。结果表明:基于XFEM的数值模拟结果与试验中的裂纹扩展路径基本吻合,验证了XFEM能够有效地应用于双裂隙岩体的裂纹扩展模拟;非岩桥区冻胀裂纹的扩展方向与预制裂隙走向相同,而岩桥区裂纹的扩展方向受到冻胀应力的影响,裂纹扩展方向偏向于另一条预制裂隙位置;冻胀裂纹的扩展模式受到围压的影响,随着围压增加,侧向卸荷过程中裂纹扩展模式由拉张模式变成拉剪混合模式,裂纹扩展方向也发生偏转。研究方法和结果可为低温裂隙岩体裂纹扩展相关研究提供参考。To study the effect of frost heaving load on crack propagation and penetration mechanism of the double-fractured rock,the crack propagation characteristics and failure modes of double-fractured specimens with different rock bridge parameters under frost heaving force were analyzed and the crack propagation rule of double-fractured specimens under the combined action of frost heaving force and lateral unloading was investigated by the extended finite element method(XFEM).The results show that the numerical simulation results are consistent with the crack propagation path in the test,which verifies that the XFEM can be effectively applied to the crack propagation simulation of the double-fractured rock mass.The propagation direction of the frost heaving crack in the non-rock bridge area is the same as that of the prefabricated crack,while the propagation direction of the crack in the rock bridge area is affected by the frost heaving stress,and the direction of the crack is inclined to the location of the other prefabricated crack.The propagation mode of the frost heaving crack is affected by confining pressure.With the increase of confining pressure,the mode of crack growth during lateral unloading changes from tensile mode to tensile-shear composite mode,and the direction of crack propagation also deflects.The research methods and results can provide a reference for the exploration of crack propagation in low-temperature fractured rock.

关 键 词：裂纹扩展 扩展有限元 双裂隙岩体 岩桥贯通 卸荷试验 

分 类 号：TU452[建筑科学—岩土工程]