Fragmentation characteristics analysis of sandstone fragments based on impact rockburst test  

作　　者：Dongqiao Liu Dejian Li Fei Zhao Chengchao Wang 

机构地区：[1]State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology [2]School of Mechanics and Civil Engineering, China University of Mining and Technology

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2014年第3期251-256,共6页岩石力学与岩土工程学报（英文版）

摘　　要：Impact rockburst test on sandstone samples with a central hole is carried out under true triaxial static loads and vertical dynamic load conditions, and rock fragments after the test are collected. The fragments of sandstone generated from strain rockburst test and uniaxial compression test are also collected. The fragments are weighed and the length, width and thickness of each piece of fragments are measured respectively. The fragment quantities with coarse, medium, fine and micro grains in different size ranges, mass and particles distributions are also analyzed. Then, the fractal dimension of fragments is calculated by the methods of size-frequency, mass-frequency and length-to-thickness ratio-frequency. It is found that the crushing degree of impact rockburst fragments is higher, accompanied with blocky character- istics observably. The mass percentage of small grains, including fine and micro grains, in impact rock- burst test is higher than those in strain rockburst test and uniaxial compression test. Energy dissipation from rockburst tests is more than that from uniaxial compression test, as the quantity of micro grains generated does.Impact rockburst test on sandstone samples with a central hole is carried out under true triaxial static loads and vertical dynamic load conditions, and rock fragments after the test are collected. The fragments of sandstone generated from strain rockburst test and uniaxial compression test are also collected. The fragments are weighed and the length, width and thickness of each piece of fragments are measured respectively. The fragment quantities with coarse, medium, fine and micro grains in different size ranges, mass and particles distributions are also analyzed. Then, the fractal dimension of fragments is calculated by the methods of size-frequency, mass-frequency and length-to-thickness ratio-frequency. It is found that the crushing degree of impact rockburst fragments is higher, accompanied with blocky character- istics observably. The mass percentage of small grains, including fine and micro grains, in impact rock- burst test is higher than those in strain rockburst test and uniaxial compression test. Energy dissipation from rockburst tests is more than that from uniaxial compression test, as the quantity of micro grains generated does.

关 键 词：Impact rockburst testFragmentsFragmentation characteristicsFractal dimension 

分 类 号：TU458[建筑科学—岩土工程]