三轴CT条件下预崩解炭质泥岩路堤填料的细观试验

Micro mechanical analysis of pre-disintegrating carbonaceous mudstone for embankment filling material based on triaxial CT test

为了研究预崩解炭质泥岩在三轴条件下的细观应力变形及损伤演化规律,采用CT专用三轴试验加载设备对其进行三轴CT试验。试验在3种固结压力下进行,得到各试件的应力变形曲线以及在不同变形阶段3个扫描层的CT数、方差和CT图像。研究结果表明:该试验方法成熟、可行,为进一步深入分析炭质泥岩物理力学特性提供了新的方法;试件固结压力越大,峰值强度越高,其内部细观表现为颗粒的错动与融合,外部表现为中部鼓起,且无明显裂纹;变形形式主要为受力均匀变形,在低围压条件下具有应变软化特征;在初始条件下,试件具有明显各向异性特点,试验后期试件差异性减小;随着变形增大,试件损伤度也逐渐增大,其细观损伤演化是一个非线性的累积增长过程。

In order to research the evolution law of stress deformation and damage of pre-disintegrating carbonaceous mudstone based on triaxial micro mechanical analytical, the CT special triaxial loading equipment was used for its triaxial CT test. The test was made on three consolidation pressures respectively. All specimens＇ curves of stress-deformation and three scan levels＇ CT number, variance and CT images in different deformation stages were obtained. The results show that the test method is mature and feasible. A new method for the further analysis of physical and mechanical properties of carbonaceous mudstone is offered. When the consolidation pressure is greater, the peak intensity of specimens is higher. The internal mesoscopic performance is rupture and fusion of particles. The external performance is central summoning up with no obvious cracks. The main deformation form is uniform deformation under the action of forces. Under the condition of lower confining pressure, specimens have characteristics of strain softening. Under the initial conditions, specimens have obvious characteristics of anisotropic deformation. In the later stage of test, the anisotropy of specimens reduces. With the increase of deformation, the specimen damage becomes bigger, and the evolution of mesoscopic damage is a non-linear accumulating and growing process.