Study on stress release law of tectonic coal under rapid unloading confining pressure
In order to study the stress release law of tectonic coal in the rapid unloading confining pres-sure,the triaxial tests of coal specimens under different unloading confining pressure rates are carried out.The characteristics of stress-strain curve and the mechanical properties of tectonic coal under different unloading confining pressure rates are compared and analyzed,and the stress release law under the condition of rapid unloading confining pressure is analyzed by fitting the test data.The results dem-onstrate that the higher the unloading confining pressure rate,the smaller the degree of deformation and peak stress when the tectonic coal is damaged.The unloading confining pressure reduces the cohesion of the coal,with the degree of deterioration being 14.02％-21.95％.The higher the unloading confining pressure rate,the stronger the deterioration effect.The unloading confining pressure reduces the deforma-tion modulus and Poisson's ratio of the coal,revealing that the unloading confining pressure aggravates the damage of the coal and coal to resist deformation are reduced.When the unloading confining pressure rate becomes high,the degradation degree of peak stress is 17.84％and the degradation degree of cohe-sion is 21.95％.In the rapid unloading confining pressure,it is easy for the tectonic coal to destabilize,and the stress release controls the non-stationary release of gas expansion energy,thus leading to the continuous development of tectonic coal outburst.
tectonic coalrapid pressure reliefunloading rate of confining pressurestress releasecoal and gas outburst
万方数据
维普
