Energy Evolution and AE Failure Precursory Characteristics of Rocks with Different Rockburst Proneness

Abstract

Mastering the precursory information of rock failure is the basis of scientifically predicting rockburst, and AE technology is an effective means to solve this problem. The conventional uniaxial loading and cyclic loading/unloading tests of metagabbro and granite were carried out with GAW-2000 uniaxial electrohydraulic rigid testing machine to evaluate rockburst proneness. The energy evolution and AE characteristics of rocks with different rockburst proneness during loading are revealed. The results show that the rockburst proneness of granite is obviously stronger than that of metagabbro based on the comprehensive evaluation method of multiple rockburst proneness index. The reasons for different rockburst proneness are analyzed from the perspective of mineral composition and microstructure. Rockburst proneness is positively correlated with energy storage capacity. The elastic energy ratio of granite is obviously larger than that of metagabbro before peak stress. The intensity of AE signals generated in the failure process of strong rockburst rock (granite) is significantly higher than that of moderate rockburst rock (metagabbro). However, the peak frequency bands and amplitude all increase obviously before failure. The b-value and memory characteristics of rock with different rockburst proneness have obvious similar change rules.

Acoustic Emission Characteristics and Damage Evolution of Sandstone with Different Pores under External Load

“…In the acoustic emission test, the AE event rate-cumulative event number change of rock during the loading process is essentially the dynamic response characteristics displayed in the stage time, and these characteristic signals can reflect the laws and phenomena of rock deformation and deterioration [20]. AE event rate refers to the number of AE events in a unit time.…”

Mechanical Properties of Metasandstone under Uniaxial Graded Cyclic Loading and Unloading

“…F. Gong pointed out that the uniaxial compression energy storage coefficient of rock can be calculated through multiple cyclic loading and unloading tests [12]. Feng Pei compared and analyzed the difference in acoustic emission signals of metamorphic gabbro and granite with different rockburst tendency under cyclic loading and unloading [13]. G. Zhao pointed out that the acoustic emission activity of mudstone under cyclic load is the most active before the peak stress, and the peak value of acoustic emission event is consistent with the peak energy [14].…”

Particle Flow Analysis of Acoustic Emission Features of Rock under Rock Burst Stress Path

“…At present, there are many researches on the mechanism of rock burst using AE features in the process of rock fracture. For example, Li et al [3] analyzed the relationship between rock burst tendency and AE features through uniaxial compression test; Tian et al [4], respectively, studied the variation rules of AE events in granite, marble, and basalt during rock burst tests; Zhang et al [5] divided rock burst into three stages using the AE dominant frequency features of granite in the failure process of biaxial loading; Su et al [6] conducted unloading failure test on granite by true triaxial test equipment, and discussed the precursor of rock burst failure using AE ringing count and b value; Pei et al [7] conducted uniaxial cyclic loading and unloading tests on granite, revealing the AE features of rocks with different rock burst tendencies in the failure process; Zhai et al [8] used AE technique to analyze the fracture evolution of granite and basalt in the process of rock burst fracture; Chu et al [9] conducted the uniaxial compression rock burst test of granite in deep tunnel and discussed the variation rule of AE features in combination with mechanical properties; Wang et al [10] proposed a multiparameter collaborative rock burst estimation method using comprehensive analysis of AE energy and dominant frequency entropy; Tan et al [11] discussed rock burst failure mechanism based on AE features of anchored sandstone during uniaxial compression failure process; Wang et al [12] explored the variation features of AE energy and event number of rocks with different rock burst tendencies during uniaxial compression deformation and failure.…”