Fracture behavior and acoustic emission characteristics of sandstone samples with inclined precracks
Litong Dou1
Ke Yang2
Xiaolou Chi1
1.State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,Anhui,China;National and Local Joint Engineering Research Center of Precision Coal Mining,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Key Laboratory of Mining Coal Safety and Efficiently Constructed by Anhui Province and Ministry of Education,Anhui University of Science and Technology,Huainan 232001,Anhui,China2.State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,Anhui,China;National and Local Joint Engineering Research Center of Precision Coal Mining,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Key Laboratory of Mining Coal Safety and Efficiently Constructed by Anhui Province and Ministry of Education,Anhui University of Science and Technology,Huainan 232001,Anhui,China
摘要：Sandstone samples with precracks of different dip angles were collected from a coal mine roof and subjected to uniaxial compression tests,and acoustic emission(AE)and scanning electron microscopy(SEM)were used to study how the crack dip angle affected the fracture mechanism.In the precracked sandstone samples,as the dip angle between the crack line and loading direction decreased,so did the peak stress and its completion time.The SEM observations revealed a fracture transition from tensile cleavage to shear slip,which was manifested by a microstructure change from aggregate to staggered.According to energy conversion,a decreased crack dip angle results in gradually decreasing total and dissipative peak energies,whose variation amplitudes at different stages are consistent with those of the peak stress of the samples.The decreased crack dip angle lowered the stress required to trigger the first appearance of AE energy peaks and ring-down counts,as well as shortening the period before the occurrence of the first AE peak signal.However,the AE energy and ring-down count during the failure stage after the stress peak increased gradually.A stepped increase was observed in the AE ring-down count curves,with each step corresponding to a jump in the stress-strain curve.From the characteristics of the AE signal of the fracture of a precracked rock sample,the occurrence of joints or faults in the rock mass can be reasonably inferred.This is expected to provide a new method and approach for predicting coal and rock dynamic disasters.
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论文发表日期：2021-03-30
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：11( 77-87 )
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