Abstract
In order to study the energy characteristics of limestone under different initial confining pressures and different unloading rates, based on MTS815 flex test GT rock mechanics test system and acoustic emission (AE) 3D positioning real-time monitoring system, the unloading test and acoustic emission synchronous monitoring of limestone are carried out. The results show that: (1) the pre peak energy process is dominated by energy accumulation, but mainly occurs in the loading stage. The proportion of energy in the unloading stage is basically unchanged, and the proportion of elastic energy is more than 0.9, which fluctuates only before the failure. During the failure, the proportion of energy in the stress drop changes dramatically, and the proportion of elastic energy decreases rapidly to 0. (2) In the coal measure strata, the energy dissipation is the main factor, the dissipation energy and its proportion increase rapidly, while in the front of coal measure strata, the energy release is the main factor, the elastic energy decreases rapidly and the dissipation energy does not increase. (3) The proportion of coal bearing strata in front of coal bearing strata is 0.68 and 0.57 respectively. Unloading elastic energy ratios before coal-bearing strata and coal-bearing strata are 0.824 and 0.876, respectively.
Highlights
According to the principle of thermodynamics, in the process of rock deformation and failure, the exchange of material and energy with the outside world constantly takes place
Based on the construction background of taoziya tunnel, this paper explores the geological conditions of surrounding rock before and in the coal measure strata, and studies the deformation energy characteristics of limestone in these two typical crossing sections
[3,4,5,6] pointed out the energy essence of rock deformation and failure, and believed that the process of rock deformation and failure is driven by energy, which is the result of the combined effect of energy dissipation and energy release
Summary
According to the principle of thermodynamics, in the process of rock deformation and failure, the exchange of material and energy with the outside world constantly takes place. Based on the construction background of taoziya tunnel, this paper explores the geological conditions of surrounding rock before and in the coal measure strata, and studies the deformation energy characteristics of limestone in these two typical crossing sections. Zhang Liming [9,10] studied the energy evolution process of limestone and marble under unloading based on the energy perspective. Based on the data of unloading test and theoretical research of surrounding rock at home and abroad, this paper explores the energy evolution law of limestone in two crossing sections under different initial confining pressure and unloading rate based on energy theory, and reveals the influence of stress state on energy release. The results of this study provide the basis for energy change during excavation and unloading, and provide guidance for the project
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.
