Multi-Crack Characterization

多裂纹表征

基本信息

批准号：
05232102
负责人：
TAKAYASU Hideki
金额：
$ 76.16万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

项目摘要

Results obtained during the research term (1993-1995) are summarized for each researcher in the following :(1) We investigated universal properties of fracture by numerical simulations. It was proven that strong macroscopic universality holds both in the cases of crack propagation model on a plane and of 3-dimensional impact fracture (Takayasu).(2) Asynthetic modelling of geothermal structure was developed which accounts for the heat discharge at the surface, the subsurface temperature, the electric resistivity structure, the Curie point depth and the inert gas composition of fumarolic gas (Yusa).(3) The multiple cracking behavior in rock was examined based on the fractal nature of acoustic emission (AE). It is demonstrated that the multiple cracking behavior in rock could be analyzed using a numerical model in conjunction with the AE results (Hashida).(4) The conditions for propagation and unstable oscillation of cracks were characterized by nondimentional fracture parameters for both … More single crack and multiple cracks (Sano).(5) A new method of detecting and monitoring fractures by use of seismic waves was proposed. The effect of injecting air into fracture was nvestigated by using both model experiments and numerical simulations. An AVO inversion method and a depth transform technique of seismic reflection data were developed. A current-convergent resistivity log by adding auxiliary sources was investigated (Sasa).(6) A fractal model to quantify the crack distribution in rock masses and a method to evaluate model input parameters by a lineament analysis of earth satellite image have been proposed. By applying the proposed method to a granite field, the crack distribution and the connectivity of cracks have been estimated (kaneko).(7) Analytical data of aero-photo and satellite images were compared with geologically identified natural fracture systems. Geologically undefined lineaments were traced by gamma ray survey. A new analytical method for satellite image was introduced (Takashima).(8) The fractal analysis on the 1500 faults of 6 groups suggests that the relationship between the width of shear zone and fault displacement, size (displacement) distribution, and the spatial distributions of faults and fault displacements show the fractal distributions whose fractal dimensions change depending on the ductility of rocks and the total energy density injected (Ohtsuki).(9) The structure of elastic wave velocity and density of the crust is known to be heterogeneous. Analyzing the well-log data obtained at 5 wells in Kyushu and Kanto, Japan, we found that their power spectra obey a power law for a wide range in wavelength from a few tens of centimeters to a few hundred meters (Sato).(10) Fractal dimensions of splitting fracture surface of welded tuff specimens using by divider method are nearly in inverse proportion to the strength. On the other hand, the coefficient of variation of dimensions near the pre-crack in CT specimens are nealry in proportion to the fracture toughness (Tano). Less

每位研究者在研究期间（1993-1995）取得的成果总结如下：（1）通过数值模拟研究了断裂的普遍性质，证明了裂纹扩展模型在裂纹扩展模型中具有很强的宏观普适性。 (2) 开发了地热结构的综合模型，其中考虑了地表的热排放、地下温度、电阻率结构、居里点深度和富马罗气体(Yusa)的惰性气体组成。(3)基于声发射(AE)的分形性质研究了岩石的多重破裂行为。使用数值模型结合 AE 结果进行分析 (Hashida)。(4) 裂纹扩展和不稳定振荡的条件由单裂纹和多裂纹的无量纲断裂参数来表征(Sano)。(5)提出了一种利用地震波检测和监测裂缝的新方法，通过模型实验和数值模拟相结合的方法研究了向裂缝中注入空气的效果。研究了通过添加辅助源的电流收敛电阻率测井（Sasa）。（6）量化岩体裂缝分布的分形模型以及评估模型输入参数的方法。提出了通过对地球卫星图像进行线形分析的方法。通过将所提出的方法应用于花岗岩领域，可以估计裂缝的分布和裂缝的连通性（kaneko）。（7）航空照片和卫星图像的分析数据。与地质上确定的天然裂缝系统进行比较，通过伽马射线勘测追踪了地质上未定义的线状。（8）对1500的分形分析。 6组断层表明，剪切带宽度与断层位移、尺寸（位移）分布以及断层和断层位移的空间分布之间的关系显示出分形分布，其分形维数随岩石的延性和总的延性而变化。注入的能量密度（Ohtsuki）。（9）已知地壳弹性波速度和密度的结构是不均匀的，分析九州和日本的 5 口井获得的测井数据。日本关东，我们发现它们的功率谱在从几十厘米到几百米的宽波长范围内遵循幂律（Sato）。（10）使用另一方面，CT 试样中预裂纹附近的尺寸变异系数几乎与断裂韧性 (Tano) 成正比。