0
  • DE
  • EN
  • FR
  • International Database and Gallery of Structures

Advertisement

Experimental Study of the Dynamic Tensile Mechanical Properties of a Coal Sandstone Disc with a Central Hole

Author(s):


Medium: journal article
Language(s): English
Published in: Advances in Civil Engineering, , v. 2020
Page(s): 1-9
DOI: 10.1155/2020/8851575
Abstract:

Deep mine rocks are often subjected to rock burst induced by dynamic load. The existence of initial holes will reduce the mechanical properties of rocks and affect the stability and safety of the tunnel excavating. In order to study the effect of the ratios of inner and outer diameter on disc specimen dynamic mechanical properties and failure modes, we use cylindrical sandstone specimens of rp50 × 25 mm to process center holes of different diameters, and a series of dynamic splitting test were carried out with a system of split Hopkinson pressure bar (SHPB) with the diameter of rp50 mm when the pressure is 0.15 MPa, 0.3 MPa, and 0.5 MPa. The results show that (1) the dynamic tensile stress-time-history curve exhibited double peak phenomena, and the second peak value is less than the first peak value, (2) the dynamic tensile stress peaks decrease nonlinearly with the increasing of the ratios of inner and outer diameter, and the dependence is more obvious when the pressure is higher, and (3) there is a tensile crack running along the loading direction in the failure modes of the five samples with the ratio of inner to outer diameter under three kinds of impact pressure. Under the same impact pressure, when the ratio of inner diameter to outer diameter is greater than the critical ratio of inner diameter to outer diameter, there is an obvious empty hole effect; that is, the sample develops secondary tensile cracks that develop from the upper and lower ends of the pore disc to the center of the inner hole. With the increase of the ratio of inner diameter to outer diameter, the width of the penetration crack increases. With the increase of impact pressure, the critical ratio of inner diameter to outer diameter decreases gradually. The research results have certain significance for understanding the mechanical properties of porous rocks.

Copyright: © Jiehao Wu et al.
License:

This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met.

  • About this
    data sheet
  • Reference-ID
    10525984
  • Published on:
    11/12/2020
  • Last updated on:
    02/06/2021
 
Structurae cooperates with
International Association for Bridge and Structural Engineering (IABSE)
e-mosty Magazine
e-BrIM Magazine