长江科学院院报2012，Vol.29Issue(8)：29-33,5.DOI:10.3969/j.issn.1001-5485.2012.08.006
现场岩体直剪试验声发射特征及其破坏机制
Acoustic Emission Characteristics and Failure Mechanism of Rock Mass in Field Shear Test
摘要
Abstract
Although many achievements have been made on the application of Acoustic Emission ( AE) technique to monitoring crack propagation in rock mass, these studies mainly focused on rock block of small size ( ≤10 cm). Only a few investigations have been done to research the failure mechanism of larger rock mass ( ≥50 cm). The SAMOS acoustic emission instrument was employed to study the failure process of jointed rock mass in field shear lest. Based on analysis of AE parameters and frequency spectrum acquired from the shear failure process of jointed rockmass, its failure mechanism can be revealed. The results showed that during the failure process of jointed rock mass, the main frequency of AE signals varied from 40 kHz to 120 kHz. The shear failure went through four phases: first, elastic deformation phase, during which no AE events happened in rock mass; second, crack initiation phase, in which a few AE events occurred and only a few cracks were generated; third, crack propagation phase when AE events increased slowly and cracks propagated steadily; and fourth, crack coalescence phase when AE e-vents increased apparently, cracks propagated and coalesced and macro fractures appeared. Different from the traditional viewpoint, which deems that the crack appears at the forward section of rock specimen, this research finds that the initial cracks appears at the middle and back-end of the specimen. With the increase of shear stress, the locations of new cracks move to the forepart. However, during the crack coalescence phase, the cracks fastened on local positions of the shear surface. Local cracking happened in jointed rock mass.关键词
节理岩体/剪切破坏/声发射/时序特征/破裂机制Key words
jointed rock mass/ shear failure/ acoustic emission/ time sequence characteristic/ failure mechanism分类
天文与地球科学引用本文复制引用
范雷,周火明,熊诗湖..现场岩体直剪试验声发射特征及其破坏机制[J].长江科学院院报,2012,29(8):29-33,5.基金项目
国家重点基础研究发展计划(973计划)课题(2011CB710603) （973计划）
中央级公益性科研院所基本科研业务费项目(CKSF2011022/YT) （CKSF2011022/YT）
水利部公益性行业科研专项经费项目(201001008) （201001008）
