Studies on Rock Mass Classification for Mining Design

所获得的结果分项如下：1.从实验和数值两个方面阐明了含水饱和裂隙岩体中的P波速度不是Wyllie等人提出的时间平均速度。在裂隙厚度总和不变的情况下，含水饱和裂隙的岩体中纵波速度随裂隙数目的增加而减小。从野外记录中可以检测到的P波的到达时间主要受其射线路径裂隙内多次反射的波的叠加控制。根据地下开采现场测量的结果，阐明了采矿方法与岩体粉碎化的关系。利用具有混合纵横比的孔隙模型可以定量地描述P波速度随含水率的变化。利用裂隙模型讨论了岩体的变形性，阐明了可以通过测量岩体的P波速、原位裂隙密度和空间力学性质来评价岩体的变形性。

The results obtained are itemized below.1. It is clarified both experimentally and numerically that P wave velocities in rock mass with water-saturated cracks are not a time average velocity proposed by Wyllie et al.2. P wave velocities in rock mass with water-saturated cracks decrease with increase of the number of cracks even if the sum of the thickness of the cracks remains constant.3. The arrival time of P wave which can be detected from the field records is mainly controlled by the superposition of the waves having multiple reflections within the cracks in their ray-path.4. From the results of a field measurement performed at the under-ground mining the relation between mining method and rock mass clasification is clarified.5. The variation of P wave velocity with respect to water content can be quantitatively illustrated by the use of a pore model with mixed aspect ratios.6. Deformability of rock mass is discussed by using the crack model, and it is clarified that the deformability of rock mass can be estimated by measuring the P wave velocity of rock mass, the crack density in-situ, and the mechanical properties of the spacimen.