Journal of Shanghai Jiao Tong University ›› 2022, Vol. 56 ›› Issue (12): 1700-1709.doi: 10.16183/j.cnki.jsjtu.2021.119

Special Issue: 《上海交通大学学报》2022年“船舶海洋与建筑工程”专题

• Naval Architecture, Ocean and Civil Engineering • Previous Articles     Next Articles

Fracture Damage Characteristics of Rock Under Pre-Peak and Post-Peak Cyclic Loading Condition

TANG Jianhui1, CHEN Xudong1(), BAI Yin2   

  1. 1. College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China
    2. Nanjing Hydraulic Research Institute,Nanjing 210029, China
  • Received:2021-04-14 Online:2022-12-28 Published:2023-01-05
  • Contact: CHEN Xudong E-mail:cxdong1985@163.com.

Abstract:

In the process of rock excavation, cyclic loading may occur before or after the peak value. In order to obtain the fracture damage evolution characteristics of rock under the pre-peak and the post-peak cyclic loading condition, the fracture tests of three-point bending granite beams were conducted by using the digital image correlation method and the acoustic emission technology. Based on the secant modulus, the acoustic emission energy and effective crack length, the rock fracture damage indexes DE, DAE, and DL were constructed respectively, and the rock fracture damage process was quantitatively analyzed. The results show that the damage index of the rock sample has an obvious rate effect. At the same number of cycles, as the loading rate increases, the damage index decreases. For the pre-peak cyclic loading condition, the fracture process of rock from elastic stage to elastic-plastic stage can be well reflected by DE. Under the condition of post-peak cyclic loading, DL can better represent the fracture damage process of rock from step up to continuous failure.

Key words: cyclic loading, rock fracture, damage index, acoustic emission, effective fracture length

CLC Number: