Abstract
This paper presents a theoretical and experimental study of the fracture of a quasi-brittle geomedium containing a cylindrical opening and subjected to a nonuniformly distributed compressive load. Laboratory tests are carried out using hydrated gypsum plaster as a model rock-like material. High-strength plaster specimens demonstrate brittle fracture, while specimens made of plaster of Paris show quasi-brittle fracture. In this case, the application of the known criteria does not allow obtaining satisfactory estimates of the fracture load. New nonlocal fracture criteria are proposed, which are the development of the average stress criterion, and point stress criterion, and which contain a complex parameter that characterizes the size of the fracture process zone and accounts not only for the material microstructure, but also plastic properties of the material, geometry of the opening, and loading conditions. The calculation results are in good agreement with the resulting experimental data.
Highlights
The tensile strength of rocks is much lower than their compressive strength
This paper presents the theoretical and experimental study of the influence of the diameter of a circular hole that simulates mine working on the fracture of a rock-like material in the stress concentration zone under nonuniformly distributed compression and the analysis of the application of nonlocal criteria for describing the fracture of a quasibrittle geomedium containing a cylindrical opening
The fracture of the rock-like materials with a circular hole under nonuniformly distributed compression is theoretically and experimentally studied, and the possibility of applying nonlocal criteria to estimate the fracture load is analyzed. It is determined in the laboratory tests that the specimens made of high-strength plaster demonstrate brittle fracture, in which case the critical pressure can be calculated within the framework of the known nonlocal fracture criteria
Summary
The tensile strength of rocks is much lower than their compressive strength. At the same time, tensile stress zones and tensile cracks (gaps) may be formed near mine workings even under compressive loads, which is very dangerous. The effect of boundary conditions on the fracture of brittle geomaterial in the stress concentration zone under a biaxial load with allowance for the size effect was studied in [1] It was shown on the basis of those experimental and theoretical studies that the influence of loading conditions on the critical (failure) stress could be well-described by nonlocal fracture criteria, developed in [2,3,4,5,6,7,8,9,10,11,12,13,14] and other works. This paper presents the theoretical and experimental study of the influence of the diameter of a circular hole that simulates mine working on the fracture of a rock-like material in the stress concentration zone under nonuniformly distributed compression and the analysis of the application of nonlocal criteria for describing the fracture of a quasibrittle geomedium containing a cylindrical opening
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
