Modeling Method for Cracks in Rocks base on the Fractal Structure of the AE Source Distribution

基于声发射源分布分形结构的岩石裂缝建模方法

基本信息

批准号：
08651106
负责人：
ITAKURA Ken-ichi
金额：
$ 1.41万
依托单位：
Muroran Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08651106/
关键词：
AE Acoustic Emission Fractal Cracks Modeling AE Source Distribution Crack Image

项目摘要

In underground construction it is important to obtain a discontinuities' model of rocks for simulations to evaluate rock stability around the working space and fluid in the rocks. In this study, three kinds of experiments were conducted to develop a more feasible modeling method of cracks in rocks based on AE (acoustic emission) monitoring data and the fractal properties of the AE source distribution.1.From hydrofracturing tests conducted on cubic-shaped rock specimens, it was found that the AE source distribution during increases in hydraulic pressure was fractal and that the relationship between amplitude and frequency of AE was also fractal. From analysis of the focal mechanisms of AE,it was possible to estimate the principal moment values, principal directions and crack types for events with a relatively large amplitude. However, it was difficult to determine the parameters of focal mechanism in most AE events.2.From fracture toughness tests using semi-circular disk specimens, it was shown that the 2-D crack and AE source distributions were both franctal. The fractal dimension of the lineaments extracted from a 2-D crack distribution image coincided with the dimension of a linear crack model obtained from AE monitoiring data.3.A 3-D crack distribution model was constructed using AE monitoring data obtained from uniaxial compression tests on prism-shaped specimens. In this model, the crack was described by a disk, and the fractal dimension of sectional lines that appeared on the surface of a specimen was adjusted to coincide with the dimension of lineaments extracted from a real crack image of the same surface of the specimen by correcting the AE parameters.It is thought that this new modeling method for cracks in rocks can be directly applied to field studies of underground construction in the future.

在地下结构中，重要的是要获得模拟的不连续性模型，以评估岩石周围的岩石稳定性和岩石中的流体。在这项研究中，进行了三种实验，以开发基于AE（声发射）监测数据的岩石中更可行的裂纹模型方法和AE源分布的分形特性。1。从液压测试中进行的水力疗法测试，对立方体的岩石标本进行了频率，并且在水中的频率上增加了一定的频率，并且在水中的频率增加了，并且在水中的频率增加了，这是在水中的频率分布，并且是频繁的频率。分形。从对AE的焦点机理的分析，可以估计具有相对较大的事件的主要力矩值，主方向和裂纹类型。然而，在大多数AE事件中很难确定焦点机理的参数。2。从使用半圆形磁盘样品的骨折韧性测试进行，结果表明，2-D裂纹和AE源分布都是Franctal。从二维裂纹分布图像中提取的谱系的分形维数与从AE Monitoiring数据获得的线性裂纹模型的维度相吻合。3.A3-D裂纹分布模型是使用从棱柱形试样上的单二维亚压缩测试获得的AE监测数据构建的。在该模型中，通过磁盘描述了裂纹，并且在样品表面出现的截面线的分形维度进行了调整，以与从校正AE参数纠正AE参数的同一表面的真实裂纹图像中提取的谱系尺寸相吻合。认为这种新的模型在Rocks中可以直接应用现场研究，从而可以直接应用现场研究。