Progress and distribution of lateral displacement of rock specimen undre the triaxial compression test

对秋吉大理岩、白滨砂岩和伯里亚砂岩进行了三轴压缩试验，探讨了试件的侧向位移进展和分布规律。在试件中心每隔30度安装12个悬臂式位移仪进行测量。首先，利用傅立叶级数对实测侧向位移数据进行近似，并将侧向位移分解为4类分量；它们分别是各向同性位移、各向异性位移、平行位移和沿生成裂缝的剪切位移。通过分析可知，在观察到表观应力降之前，各向同性分量占主导地位，之后，当试件脆性时，剪切引起的位移占主导地位。另一方面，当试件为塑性时，各向同性分量在整个试验过程中都占主导地位。更明显的是，平行运动分量从试验开始就出现了，各向异性分量开始出现在峰值强度之前或之后。其次，计算了所有岩石类型的最大侧向位移。由此分析可知，秋吉石大理岩中，各向同性分量产生的位移大于沿生成裂隙剪切产生的位移。在白滨砂岩中，各向同性分量产生的最大侧向位移的大小与剪切作用产生的最大侧向位移的大小几乎相同。此外，在Berea砂岩的情况下，明确了最大位移是由剪切引起的。最后，利用x射线CT扫描检测了明吉大理岩的内部破坏过程，并分析了试件侧向位移与内部破坏的关系。由分析可知，内破坏随轴向应变的增加而增大，且视断裂方向垂直于内破坏主导方向。少

Triaxial compression tests were conducted for Akiyoshi marble, Shirahama sandstone and Berea sandstone to discuss about the progress and the distribution of lateral displacement of the specimens. The measurements were conducted at the center of the specimens by using twelve displacement meters of cantilever type mounted around the specimen in every 30 degrees. First, the measured lateral displacement date were approximated by Fourier series and the lateral displacement was decomposed into four types of component. The were isotropoic displacement, anisotropic displacement, parallel movement and the displacement by the shearing along the generated fracture. From this analysis, it was cleared that the isotropic component was dominant until the apparent stress drop was observed and after that , the displacement according to the shearing was dominant when the specimen was brittle. On the other hand, when the specimen was plastic, the isotropic component was dominant all through the test. Mo … More reover, it was cleared that the component of parallel movement was sppeared from the start of the test and the anisotropic component started to appear just before or after the peak strength. Second, the maximun lateral displacement was calculated for all the rock types. From this analysis, it was cleared that in the case of Akiyioshi marble, the displacement generated by the isotropic component was larger than that by the shearing along generated fracture. In the case of Shirahama sandstone, it was cleared that the magnitude of the maximum lateral displacement genreated by the isotropic component was almost the same to that by the shearing. Furthermore, in the case of Berea sandstone, it was cleared that the maximum displacement was caused by the shearing. Last, the progress of inner failure of Akiyoshi marble was detected by using X-ray CT scanner and the relation between the lateral displacement and the inner failure of the specimen. From this analysis, it was detected that the inner failure became large according to the progress of axial strain and the direction of apparent fracture was perpendicular to the diectiron of dominant inner failure. Less