利用分岔分析理论研究高孔隙度岩石的局部化变形

【作者】 王鑫；

【导师】 席道瑛； 徐松林；

【作者基本信息】 中国科学技术大学 ， 地球物理， 2006， 硕士

【摘要】 地壳中普遍存在各种尺度的局部化变形，理解这些局部化变形的发生和演化机制对地球物理学，大地构造学是非常基础的。多孔岩石是各种地壳运动的主体，同时也是流体及矿物的载体。因此研究高孔隙度岩石的局部化变形，对于理解地壳的变形，以及地壳中发生的各种地质作用过程有重要的作用。高孔隙岩石的三种局部化变形方式：压缩带、剪切带和膨胀带是常见的三种在野外已经找到证据的变形方式。其中压缩带和剪切带在轴对称压缩实验中得到了验证。运用Rudnicki和Rice(1975)的分岔分析理论模型以及Issen和Olssen等人对此模型进行的改进，Issen和Rudnicki(2001)提出了新的关于局部化变形带的判定条件。本文通过引入帽子屈服曲面，并对帽子曲面和塑性势能曲面用椭圆函数和圆函数形式进行了简化，从而得到了新的判定条件。在验证过这个模型的合理性并讨论过其优越性之后，我们认为这个模型比Issen和Rudnicki(2001)具有更好的应用性。此外，本文还对大量高孔隙砂岩的对称三轴压缩实验的实验结果进行了分析，提出了新的观点，并对实验中的差应力—轴向应变曲线中的某些特性进行了研究，对差应力—轴向应变的全程应力应变曲线进行了区段讨论，对与“应力平台”相对应的压缩带的产生原因进行了研究，还对部分实验中的声发射现象进行了分析。更多还原

【Abstract】 Many localized deformation exist in the crust. Understanding the formation and the evolution of these deformation are fundamental to geophysics and tectonics. Porous rock is not only the major subject of kinds of movement of crust but also the carrier of fluid and minerals. Therefore, investigation of the localized deformation of high porous rock is important for studying the deformation of the crust and geology action. Three types of localized deformation of high porous rock: compression zone, shear zone and dilatation zone have been found in the field, and compression zone and shear zone have been confirmed in labs. With the bifurcation analysis theory by Rudnicki and Rice (1975) and the improvement to this theory by Issen and Olssen, Fssen and Olssen (2001) proposed a new set of justify conditions of localized deformation zones. This article introduce the "cap yield curve model", simplify the cap yield surface and plastic potential energy surface by ellipse and circle, and get a new justify condition. After verifying the rationality an discussing the advantage of this model, the new model is thought to have a better applicability than older one. Besides, this article analyze amount of tri-axis compression experiments of high porous rock, and study some figures of stress-strain curve. It also discusses the segments of whole stress-strain curve, investigates the "stress-flat", which relates to the compression zone. It also studies the acoustic emission.更多还原