Large Lateral Deformation Characteristics of Simulated Columnar Jointed Rock Mass under Uniaxial Compression Tests

2015 ◽  
Vol 1 (3) ◽  
pp. 122-127
Author(s):  
Zhi Song ◽  
Weimin Xiao ◽  
Huayong Ni ◽  
Gang Fan
Keyword(s):  
Rock Mass ◽  
Uniaxial Compression ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Deformation Characteristics ◽  
Lateral Deformation ◽  
Compression Tests ◽  
Columnar Jointed Rock Mass

scholarly journals Model Test Study on the Anisotropic Characteristics of Columnar Jointed Rock Mass

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1528
Author(s):  
Zhende Zhu ◽  
Xiangcheng Que ◽  
Zihao Niu ◽  
Wenbin Lu
Keyword(s):  
Rock Mass ◽  
Failure Modes ◽  
Engineering Application ◽  
Jointed Rock ◽  
Structural Features ◽  
Jointed Rock Mass ◽  
Hexagonal Prism ◽  
Compression Tests ◽  
Test Study ◽  
Columnar Jointed Rock Mass

Because of its special structure, the anisotropic properties of columnar jointed rock mass (CJRM) are complicated, which brings difficulty to engineering construction. To comprehensively study the anisotropic characteristics of CJRM, uniaxial compression tests were conducted on artificial CJRM specimens. Quadrangular, pentagonal and hexagonal prism CJRM models were introduced, and the dip direction of the columnar joints was considered. Based on the test results and the structural features of the three CJRM models, the deformation and strength characteristics of CJRM specimens were analyzed and compared. The failure modes and mechanisms of artificial specimens with different dip directions were summarized in accordance with the failure processes and final appearances. Subsequently, the anisotropic degrees of the three CJRM models in the horizontal plane were classified, and their anisotropic characteristics were described. Finally, a simple empirical expression was adopted to estimate the strength and deformation of the CJRM, and the derived equations were used in the Baihetan Hydropower Station project. The calculated values are in good agreement with the existing research results, which reflects the engineering application value of the derived empirical equations.

scholarly journals The Method of Determining Excavation Damaged Zone by Acoustic Test and the Application in Engineering Cases

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qian-Cheng Sun ◽  
Hao-Sen Guo ◽  
Zhi-Hua Xu ◽  
Yue Liu ◽  
Xiao Xu
Keyword(s):  
Rock Mass ◽  
Damage Evolution ◽  
Hard Rock ◽  
Damage Zone ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Surrounding Rock ◽  
Excavation Damaged Zone ◽  
Damaged Zone ◽  
Columnar Jointed Rock Mass

It is very important to accurately determine the depth of excavation damaged zone for underground engineering excavation and surrounding rock stability evaluation, and it can be measured by acoustic test, but there is no quantitative method for analysis of the results, and it relies heavily on the experience of engineers, which leads to the low reliability of the results and also limits the application of the acoustic method. According to substantial field test data and the feedback of surrounding rock support parameters, the boundary method is proposed to determine the depth of excavation damaged zone in surrounding rock based on the relation between the ultrasonic velocity of measured point and the background wave velocity of rock mass. When the method is applied to the columnar jointed rock mass of Baihetan and the deep-buried hard rock of Jinping, the excavation damaged zone was well judged. The results in the Baihetan project show that the proposed method of determining excavation damage zone by the acoustic test can well demonstrate the anisotropy characteristics of the columnar jointed rock mass, and the damage evolution characteristics of jointed rock mass at the same position can also be obtained accurately. Moreover, the method also can accurately reveal the damage evolution process of the deep-buried hard rock under the condition of high ground stress, which proved the applicability of this method in jointed or nonjointed rock masses.

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