【作者】 黄梅；

【导师】 潘一山；

【作者基本信息】 辽宁工程技术大学 ， 工程力学， 2006， 硕士

【摘要】 等间距断裂如节理、矿区断裂、海洋断裂、地震网络等作为一种有节律的地质分布现象广泛存在,而且小至节理大至地壳断裂的空间网络结构大体一致,这其中必定包含有迄今尚未发觉的深刻意义,并且可能是由同一机理或有本质联系的机理所控制。因此研究结构面等距性的规律十分重要,它不仅是我们将地质信息合理地抽象为地质模型及力学模型的依据,也是岩体力学理论得以建立和发展完善的力学基础,而且理解了等间距断裂产生的条件、影响因素及机理,还可以预测受断裂控制的矿体分布及对大尺度的岩石破裂地震这种现象做出预测。本文试图在这方面作一尝试性的探讨。首先通过平面应力状态下加载速率对岩石破坏形态影响的实验,观察到加载速率的变化能够引起张拉形断裂向剪切形断裂的转化。而地震的发生通常认为是岩体剪切断裂的过程,而导致岩体剪切断裂的原因是地球内部贮存的应变能突然释放引起的动态加载的结果。因此完全有理由推断在动态加载条件下即地震力作用时,地壳岩石有可能发生剪切断裂并形成近似而有节律的等间距现象。其次通过局部区域范围内地表岩层在双侧向等应力作用下变形破坏规律的相似材料模拟实验研究,提出了水平压力是导致岩层先出现屈曲变形而后发生剪张破裂形成等距结构面的力学原因。然后应用板的屈曲理论及褶皱与断裂的关系分析了岩石在不同围压下对X型剪切节理间距的影响,并应用屈曲褶皱控制断裂的概念对地表岩层相似模拟实验现象及地震网络的形成机理进行了深入分析,初步认识地震活动具有的块体性即等间隔活动的特点可能受着地壳屈曲的控制。最后应用梯度塑性理论在宏观范围内从应变局部化的角度提出了水平压缩应力(应变)的波动传播可能是导致岩层先出现屈曲变形而后发生剪张破裂并伴随共轭延性剪切局部化破裂带现象的力学原因,并建立了平面应力状态下岩石梯度塑性理论模型。通过对塑性应变场的解析分析可推知塑性应变曲面的分布具有等间距分布规律,其网络的分布格局及幅值大小与围压、岩样尺度、弹性模量E、降模量λ、材料内部参数l有关。这一分析结果与相关文献试验结论一致。说明应用梯度塑性理论不仅能够近似描述等间距现象,而且可以把大尺度地更多还原

【Abstract】 Fracture spacing , such as joint , mining area rupturing , ocean rupturing , earthquake network ,etc. are the rhythm phenomenon of geology distributed and existed extensively, and the structure of the whole space network is unanimous from joint to the earth’s crust rupture, among them, this must include the profound meaning that not discovered so far, and may be controlled by the same mechanism or the mechanism with the essential connection., So it is very important to study the regularity of uniformpiston of structural face. It is not only a foundation that we abstract the information of geology as the model of geology and mechanics but also is basis that theory of rock mechanics had been founded and perfected. We understand the condition and the influence factor or mechanism, which fractures spacing had been occurred, and also can forecast the distribution of ore body as well as the phenomenon of earthquake. In this study, some research had been carried out in this respect. Firstly, by the experiment with the influence of loading rate to rock breaking state under the condition of plane stress, we had observed that the change of loading rate could bring the transform of jacking rupture to shear rupture. The occur of earthquake is usually thought as the process of ore body’s shear rupture, and the reason is the result in dynamic loading that the strain energy within the earth suddenly released. The crustal rock will occur the shear rupture and form the phenomenon of approximate and rhythm uniformpiston. Secondly, the simulation experiment of equivalent material had been carried out for the research of deformation rupture rule of top stratum with two-side equal stress in local area. Presented the mechanic reason that the terrane appeared bucking deformation and then entered shear-open rupture, finally formed uniformpiston of structural face with horizontal pressure. Using the bucking theory of the board and the relationship between bucking fold and rupture, we probed into the influence of different confining pressure to X shear joint spacing of rock and using the concept of bucking fold controlling rupture, the phenomenon of resemble simulation experiment to top stratum and formative mechanism of earthquake network were analysis deeply. We have roughly recognized that the pieces character of seismic activity, namely the character of equal interval activity was controlled by the earth’s crust flections Finally, we presented that wave transfer of horizontal compressive stress (strain) is the mechanics reason that the terrane appeared bucking deformation and then entered shear-open rupture by using of plasticity theory of gradient from angle of localization of strain within macroscopical range, and the model of strain gradient theory is established in plane strain state. By the analysis of the plastically deforming area of rock using plasticity theory of gradient, we can conform that the distribution of the plastically deforming curved face have the law of fracture spacing , the networks distribution pattern and the argument are related to confining pressure、 the scale of rock 、Young’s modulus E 、falling modulus λ 、 internal parameter of the materiall and analyze how confining pressure affect plastically deforming ε p. The conclusion is identical in some document results, this prove that plasticity theory of gradient not only can approximately describe the fracture spacing phenomenon, but also we can unify large scale earthquake network and small conjugate shear network of rock. In this paper, the discussion for the phenomenon of rock fracture with different scale was carried out at home and abroad firstly, and the above conclusions acquired by the research of experiment and theory. This subject presents the challenge to the theory of rock mechanics, and has huge application values for the prediction of rupture, energy sources prediction controlled by rupture, the control of earthquake’s occur and evolution and prevention of engineering disaster.更多还原