Research on damage characteristics and energy evolution law of coal rock under cyclic gradient loading
ZHANG Minbo
LI Chunxin
ZHANG Shilong
HUANG Qiangyong
NIU Yixiao
JIA Yuhao
LIU Rentao
Abstract：In coal mining,the rock mass is often in the process of repeated cyclic loading due to the influence of excavation and un-loading factors.In order to study the damage and failure characteristics and energy evolution law of coal and rock under cyclic gradi-ent loading,a uniaxial cyclic gradient loading experiment was carried out on coal samples,and deformation failure characteristics,in-put energy density,dissipated energy density and damage variables of the coal samples under different cyclic gradient loading were compared and analyzed.The results show that with the increase of the cyclic gradient stress,the number of cycles and the peak strength of the coal samples decrease,which are 17.97,14.86,11.23,and 10.53 MPa;in cyclic gradient loading,most of the input en-ergy density is stored inside the rock sample in the form of elastic strain energy,and the dissipation energy increases between 0.2%and 40%of the total input energy in a single cycle.Cumulative dissipation is selected as the quantitative index of the whole process of coal and rock damage,and the Logistic equation is used to fit the coal and rock damage,and the evolution model of coal and rock damage is obtained.
Keywords：coal rock damagesurrounding rock controlcyclic gradient loadingfailure deformationdissipated energyenergy evolutiondamage characteristics
Publication Date：2024-02-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 133-140 )