Study on coal compressibility and correction of compression amount based on compressibility of mercury injection test

In order to improve the reliability and suitability of the mercury injection test results,with accurate explanation of the pore struc-ture of the coal,according to the basic principle of the elastic mechanics,in combination with the idea of the fractal dimension,within thepressure scope of 10 ~ 206 MPa,the compressed coefficient of th e coal was calculated based on the mercury injection data,in combinationwith the liquid nitrogen adsorption data,correction was conducted on the mercury injection test res ults. The base compressed coefficient ofthe coal sample was 0. 671x10-10~ 1. 23x 10-10m2/ N,the difference between the total pore volume after and before the correction was48.62% ~ 54. 89%. The pore structure and liquid nitrogen adsorption test results were more close to each other. When the pressure was o-ver 206 MPa,coal pore struc ture would be varied complicated. The test results of the related pore diameter less than 6 nm would not be forapplication. When the pressure was in 10 ~ 206 MPa,the acc umulated compression amount and the backfill value were in a power functionrelationship.