Influence of prefabrication defects on dynamic properties of granite under cyclic loading

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Oct.2025, Vol.48 No.10: 1411-1421

DOI: 10.3969/j.issn.1003-5060.2025.10.017

Authors

DING Xiaobin $ ^{1,2} $, ZHAO Junxing $ ^{1} $, DONG Yaojun $ ^{1} $

(1. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China; 2. South China Institute of Geotechnical Engineering, Guangzhou 510640, China)

Abstract and Keywords

Abstract: The fracture defects in granite produced by long-term exposure to various loads can change the stability of the rock, endangering the project and personnel safety. In this paper, the effects of confining pressure, dynamic load frequency, dynamic stress amplitude and cycle times on the dynamic properties of prefabricated defective granite are studied by using triaxial dynamic load cycle test. It is found that with the increase of the degree of defect, the dynamic elastic modulus of rocks decreases, while the dynamic damping ratio increases. With increasing frequency, the dynamic elastic modulus of rocks with different defects increases at an accelerating rate, and the dynamic damping ratio also increases gradually. With the increase of the dynamic stress amplitude, the dynamic elastic modulus of rocks with different defects increases, while the dynamic damping ratio decreases. The dynamic elastic modulus and dynamic damping ratio of defective rocks initially decrease with the number of cycles and then tend to stabilize. As the confining pressure increases, the dynamic elastic modulus of rocks with different defects increases at an accelerating rate, while the dynamic damping ratio decreases. The multivariate tests were carried out, yielding well-rounded findings. It provides a reference for the study of the dynamic properties of defective granites and a preparation for the inverse analysis of the dynamic properties of granites.

Keywords: triaxial load; prefabrication defects; confining pressure; frequency; dynamic stress amplitude; cycle times; dynamic properties

作者信息

丁小彬 $ ^{1,2} $，赵君行 $ ^{1} $，董耀俊 $ ^{1} $

(1. 华南理工大学土木与交通学院，广东广州 510640；2. 华南岩土工程研究院，广东广州 510640)

摘要和关键词

摘要: 花岗岩因长期受到各种荷载作用产生的裂隙缺陷会改变岩石的稳定性, 危及工程和人员的安全。文章利用三轴动荷载循环试验, 分析围压、动荷载频率、动应力幅值及循环周次对预制缺陷花岗岩动力特性的影响。试验结果表明: 花岗岩的动弹性模量随缺陷程度的增大递减, 而动阻尼比随缺陷程度的增大而递增; 频率增大, 不同缺陷花岗岩动弹性模量增大, 其增长幅度和动阻尼比也逐渐增大; 动应力幅增大, 不同缺陷花岗岩动弹性模量增大, 动阻尼比减小; 缺陷花岗岩动弹性模量、动阻尼比均随循环周次先降低后趋于稳定; 围压的增大, 不同缺陷花岗岩动弹性模量增大, 增长幅度也逐渐增大, 动阻尼比降低。该试验在多因素变量下进行, 所得结论较为全面, 既为研究缺陷花岗岩动力特性提供了较好参考, 也为花岗岩动力特性的反演分析工作奠定基础。

关键词: 三轴荷载；预制缺陷；围压；频率；动应力幅；循环周次；动力特性

Funding

国家自然科学基金资助项目（41827807）；广东省现代土木工程技术重点实验室2021年子课题资助项目（2021B1212040003）

合肥工业大学学报(自然科学版)

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