基于尺寸效应的岩石声发射时空特性数值模拟

为研究不同大小尺寸岩石破坏过程中的声发射时空分布和演化规律及其对岩石破坏过程声发射的影响，以某矿山岩石力学参数为依据，利用数值软件对相同高径比、不同大小尺寸的6组岩样进行试验研究。试验表明当岩样尺寸小时，大的声发射事件主要出现在岩样大破裂贯通前后，声发射在岩样中从当初的随机性分布，到过峰值载荷之后大量集聚在岩样中部。试样尺寸较大时，未达到峰值应力前声发射较少出现，且分布弥散，大的声发射事件仅在峰值载荷后出现1次，其能量和数量均是声发射历史上最显著的，在试样中两处聚集成核，这与不同尺寸岩样内部包含不同缺陷强度离散性有密切关系。

Numerical Simulation on AE Temporal and Spatial Characteristics of Rock based on Scale Effect

In order to study the AE(acoustic emission) temporal and spatial evolution and distribution in the failure process of different size rocks and its influence on the AE in failure process of rock, and according to the physic-mechanical parameters of a mine rock specimen, the AE temporal and spatial characteristics of rock under six kinds of different scales with the same homogeneity and ratio of height to diameter were studied by using numerical simulation software. The test results show that the larger AE events obviously occur before and after the formation of the main fracture for a smaller rock specimen, in which AE events transited from disorder in the whole specimen to nucleation in the middle of specimen at the phase of post-peak. For a larger rock specimen, few random AE events prior to peak stress and larger AE events with remarkable counts and energy nucleate and occur only after the peak stress, which is closely related to the discreteness of defects strength in different sizes of rock samples.