scholarly journals Radon release from underground strata to the surface and uniaxial compressive test of rock samples

2016 ◽  
pp. 409-418 ◽  
Author(s):  
Wei Zhang
Keyword(s):  
Compressive Test ◽  
Rock Samples ◽  
Uniaxial Compressive Test

scholarly journals Failure Mechanism of Rock Specimens with a Notched Hole under Compression—A Numerical Study

2021 ◽  
Vol 11 (17) ◽  
pp. 7797
Author(s):  
Amin Manouchehrian ◽  
Pinnaduwa H. S. W. Kulatilake ◽  
Rui Wu
Keyword(s):  
Numerical Study ◽  
Confining Pressure ◽  
Compressive Test ◽  
Separate Model ◽  
Failure Evolution ◽  
Uniaxial Compressive Test ◽  
Notch Length ◽  
The Stability ◽  
Fracturing Mechanism ◽  
Rock Specimens

Discontinuities are natural structures that exist in rocks and can affect the stability of rock structures. In this article, the influence of notch presence on the strength and failure evolution around a hole in compressed rock specimens is investigated numerically. Firstly, the uniaxial compressive test on a rock specimen with a circular hole is modeled, and the failure evolution in the specimen is simulated. In a separate model, notches are created at the surface of the hole. Results show that, when the notches are created in the model, a failure zone around the hole is transferred to a distance away from the surface of the hole. In addition, a parametric study is carried out to investigate the influence of the notch length and the confining pressure on the fracturing behavior of the specimen. Numerical results presented in this article indicate that the presence of notches at the surface of the hole and their dimensions can affect the fracturing mechanism of the specimen. In some cases, the failure at the boundary of the hole is prevented when the notches of certain dimensions are added to the hole. The insights gained from this numerical study may be helpful to control the failure around underground excavations.

Quantitative Analysis of Several Influencing Factors on TBM Advance Speed

2012 ◽  
Vol 594-597 ◽  
pp. 1318-1323
Author(s):  
Chao Li ◽  
Joachim Tiedemann ◽  
Hong Wei Zhou
Keyword(s):  
Compressive Strength ◽  
Quantitative Analysis ◽  
Rock Strength ◽  
Thrust Force ◽  
Compressive Test ◽  
Experiment System ◽  
Uniaxial Compressive Test ◽  
Csm Model ◽  
The Relationship ◽  
Advance Speed

Aiming at the problem of a difference between the TBM advance speed estimated by the NTNU and CSM model, and the actual advance speed, a quantitative analysis is carried out in the paper. Combining the experimental results of the uniaxial compressive test with the rock mechanics experiment system TAW-2000 and MTS815, the paper quantitatively characterizes the main parameters including the rock compressive strength, elastic modulus, abrasiveness, and the thrust force of cutterhead, corresponding to TBM advance speed by using the method of quantitative analysis of multi-factors. Moreover, the relationship between the TBM advance speed and the parameters was established. It is indicated that higher rock strength, abrasion and a smaller thrust force of cutterhead are reasons resulting in a lower TBM advance speed.

scholarly journals Multiscale Laboratory Study and Numerical Analysis of Water-Weakening Effect on Shale

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Zhen Li ◽  
Shangge Liu ◽  
Wentao Ren ◽  
Jinjin Fang ◽  
Qinghua Zhu ◽  
...  
Keyword(s):  
Water Immersion ◽  
Triaxial Compression ◽  
Mechanical Tests ◽  
Compressive Test ◽  
Brazilian Disk ◽  
Rock Interaction ◽  
Influence Of Water ◽  
Mineral Components ◽  
Uniaxial Compressive Test ◽  
Water Contents

Water-weakening effect is one of the most important factors inducing large deformation and stability problems of shale strata in the Huangjiazhai Tunnel. The influence of water on shale with various water contents and its mechanism still needs more study. In this paper, the X-ray diffraction and water absorption test were first conducted to determine the influence of mineral components on water-rock interaction. Then, a series of rock mechanical tests, including uniaxial compressive test, Brazilian disk test, and triaxial compressive test, were carried out on shale under dried condition, wetted condition with various water contents, and saturated condition. For the uniaxial compression, tension, and triaxial compression, the softening coefficient could reach 0.38, 0.63, and 0.52, respectively. Based on the macroscale experiments, a numerical case study of tunnel excavation was investigated to evaluate the water effect. Finally, with the aid of scanning electron microscope and failure morphology, the mechanism of water-weakening effect on shale was discussed from microscopic and macroscopic perspectives. The thickness of the double layer increases with the increase of water immersion time. This paper provides a set of useful data for reference in construction in shale strata, and a methodology to evaluate water-weakening effect through laboratory and numerical modelling approaches.

scholarly journals UNIAXIAL COMPRESSIVE TEST FOR COMPRESSIVE DUCTILITY OF PRECAST CONCRETE PILE

2021 ◽  
Vol 27 (66) ◽  
pp. 726-731
Author(s):  
Hidekazu WATANABE ◽  
Kiyoshi MIYAHARA ◽  
Yuuri OHTSUKA ◽  
Tomohisa MUKAI ◽  
Tsutomu HIRADE ◽  
...  
Keyword(s):  
Precast Concrete ◽  
Compressive Test ◽  
Concrete Pile ◽  
Uniaxial Compressive Test
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