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刘剑航 , 王桂尧 , 郑    涛 , 蔡    林

 

(长沙理工大学 土木工程学院 , 长沙   410114)

摘  要: 为分析不同侧向围压条件下闭合多裂隙对类岩石试件力学行为 、变形特征及破坏模式的影响 , 采用高强度石膏并通过预埋抽条法制作含闭合多裂隙的类岩石试件 , 对其开展双轴压缩试验 , 引入盒维数法计算裂纹分形维数 , 定量表征试件的损伤破裂程度 , 并探究抗压强度与裂纹分形维数的关系 。结果表明 : 中低围压时 , 试件的起裂应力 、抗压强度 、弹性模量和峰值应变随裂隙倾角的增大均先减小后增大 , 在裂隙倾角为 45° 时最小 。高围压时 , 试件的抗压强度 、弹性模量和峰值应变出现下降趋势 ; 在不同的围压和裂隙形式下 , 试件破坏模式主要包括拉伸破坏 、剪切破坏 、拉剪复合破坏和压溃破坏 ; 裂纹分形维数随着裂隙倾角的增大先增大后减小 , 在裂隙倾角为 45° 时最大 。裂纹分形维数随侧向围压的增大逐渐减小 , 试件的抗压强度和裂纹分形维数近似服从负相关关系 。研究结果不仅丰富了多裂隙岩石理论体系 , 还为隧道和边坡支护等工程问题提供了参考。

关键词: 双轴压缩 ; 岩体强度 ; 岩体变形 ; 破坏模式 ; 分形维数

中图分类号: TU458      文献标志码: A      文章编号: 1005-8249 (2026) 05-0056-08

DOI:10. 19860/j. cnki. issn1005-8249. 2026. 05. 009

 

LIU Jianhang, WANG Guiyao, ZHENG Tao, CAI Lin

(School of Civil Engineering, Changsha University of Science and Technology, Changsha 410114, China)

Abstract : To analyze the influence of closed multi-cracks on the mechanical behavior, deformation characteristics and failure mode of rock - like specimens under different lateral confining pressures, high - strength gypsum was used and rock - like specimens with closed multi-cracks were fabricated by the pre-installed strip method. Biaxial compression tests were conducted on these specimens. The box dimension method was introduced to calculate the fractal dimension of cracks, and the degree of damage and fracture of the specimens was quantitatively characterized. The relationship between compressive strength and the fractal dimension of cracks was also explored.  The research results show that under medium and low confining pressure conditions, the initiation stress, compressive strength, elastic modulus and peak strain of the specimens all decrease first and then increase with the increase of the fracture inclination Angle, and are the smallest when the fracture inclination Angle is 45° . Under the condition of high confining pressure, the compressive strength, elastic modulus and peak strain of the specimens  showed a downward trend. Under different confining pressures and fracture forms, the failure modes of specimens mainly include tensile failure, shear failure, combined tensile - shear failure and crushing failure.  The fractal dimension of the crack first increases and then decreases with the increase of the crack inclination Angle, and it is the largest when the crack inclination Angle is 45° .  The crack fractal dimension gradually decreases with the increase of lateral confining pressure, and the compressive strength of the specimen and the crack fractal dimension approximately follow a negative correlation.  The research results not only enrich the theoretical system of multi-fracture rocks, but also provide references for engineering problems such as tunnel and slope support.

Key words: biaxial compression; rock mass strength; rock mass deformation; failure mode; fractal dimension

作者简介 : 刘剑航 (2000—) , 男, 硕士研究生, 研究方向 : 岩土工程。

通信作者 : 王桂尧 (1963—) , 男, 博士, 教授, 研究方向 : 岩土工程。

收稿日期 : 2025-04-09