作者：沈忠, 付小敏, 黄兴建, 张昕, 宾婷婷

作者单位：成都理工大学 地质灾害防治与地质环境保护国家重点实验室, 四川 成都 610059

关键词：声发射;振铃计数率;分形;相空间维数;关联维数

摘要：

为研究软岩声发射序列的分形特征,在MTS815程控伺服刚性试验机上,对膏质泥岩、粉砂岩、页岩进行单轴压缩下的声发射试验。结果表明:声发射序列分形是有限度的,超过一定限度不再分形;随相空间维数m的增加,双对数图整体下移且无标度区变窄,同时关联维数D呈现出增加-稳定-发散的发展过程;3类岩石均在应力水平40%~50%时,关联维数D值最大,随后声发射活动在主破裂附近产生丛集现象,关联维数降低至较低水平;声发射分形维数的演化表现为波动-上升-有起伏的整体下降链式模式,同时得出损伤破裂的分形识别模式为峰值-第2波峰模式或称反对号()模式。据此为岩体稳定性监测提供一种新的识别方法。

Study on the fractal characteristics of acoustic emission sequence of soft rock

SHEN Zhong, FU Xiaomin, HUANG Xingjian, ZHANG Xin, BIN Tingting

State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China

Abstract: In order to study on the fractal characteristics of acoustic emission (AE) sequence of soft rock, AE test of the gypsum mudstone, fine sandstone and shale was carried out in the MTS815 programmable servo rigidity testing machine under uniaxial compression. The results show that the fractal of AE sequence is limited, and exceeding a certain limit is no longer a fractal; with the increase of phase space dimension (m), double logarithmic diagram move down, scale-free zone is narrowed and the correlation dimension (D) shows the development process of increase-stabilization-dispersion at the meantime; when three types of rocks are in the stress level of 40%-50%, the correlation dimension (D) is the biggest, and then the AE produce has the cluster phenomenon near the main rupture and the correlation dimension reduces to a low level; the evolution of AE fractal dimension is volatility-rose-decline with fluctuations and fractal recognition pattern of damage and destruction is "peak to the second peak" mode or called "against ture(√)" mode. This provides a new recognition method for monitoring the stability of rock mass.

Keywords: acoustic emission;ringing counts rate;fractal;phase space dimension;correlation dimension

2016, 42(6): 9-13  收稿日期: 2015-12-20;收到修改稿日期: 2016-01-28

基金项目: 国家自然科学基金项目(41272321)

作者简介: 沈忠(1990-),男,湖北襄阳市人,硕士研究生,专业方向为岩土工程。

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