Fracture Mechanics for Heterogeneous Materials and its Application to Controlled Blasting and Splitting

异质材料断裂力学及其在控制爆破和劈裂中的应用

基本信息

批准号：
12450408
负责人：
KANEKO Katsuhiko
金额：
$ 5.25万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

Although the rock is generally considered to be a heterogeneous material, the rock is usually treated as a homogeneous material in the fracture mechanics. In this study, the influence of heterogeneity on the crack growth in rock was analyzed and discussed.(1) Double-Torsion test was performed to investigate the anisotropy of subcritical crack growth behavior in granite that is a typically heterogeneous rock. The experimental results confirmed that subcritical crack growth in granite was anisotropic and depended on the direction of the crack growth. Furthermore, the geometry of crack path becomes smoother in the case that the crack propagates with lower stress level. These behavior and characteristics are caused by the oriented microcracks. From these results, it is concluded that the crack growth in heterogeneous rock takes place with lower fracture energy by linking of mierocracks existing nearby crack tip.(2) Mineralogical examination, physical properties measurement and slake durability tests of some argillaceous clastic rocks have been carried out and it was made clear that the mineral composition and texture of rocks in addition to smectite mineralogy have a great influence in rock durability.(3) A numerical simulation method based on the finite element method and fracture mechanics for heterogeneous rock was proposed. Analyzing fracture processes of rock splitting by the breaker and rock fragmentation in bench blasting, the mechanism of splitting and fragmentation were clarified.

虽然岩石通常被认为是非均质材料，但在断裂力学中通常将岩石视为均质材料。本研究分析讨论了非均质性对岩石裂纹扩展的影响。(1)采用双扭转试验研究了花岗岩这种典型的非均质岩石亚临界裂纹扩展行为的各向异性。实验结果证实花岗岩中的亚临界裂纹扩展是各向异性的并且取决于裂纹扩展的方向。此外，在裂纹以较低应力水平扩展的情况下，裂纹路径的几何形状变得更加平滑。这些行为和特征是由定向微裂纹引起的。从这些结果可以看出，非均质岩石中的裂纹扩展是通过裂纹尖端附近存在的微裂纹的连接而以较低的断裂能进行的。(2)对一些泥质碎屑岩进行了矿物学检验、物理性能测量和熟化耐久性试验。明确了除蒙脱石矿物学外，岩石的矿物成分和结构对岩石的耐久性也有很大的影响。(3)提出了一种基于有限元法和断裂力学的非均质岩石数值模拟方法。建议的。分析了破碎锤劈裂岩石的破碎过程和台架爆破中岩石破碎的过程，明确了岩石劈裂破碎的机理。