论文部分内容阅读
对3组15个不同破损孔径的一维损伤膨胀土圆柱试样,进行控制净围压分别为50,100,150kPa的三轴剪切试验,研究低含水率(w=7%)条件下一维圆柱孔破损重塑膨胀土的应力-应变特性、体变特性以及破损形态.试验结果发现:与以往常规含水率(约20%)土样不同,破损孔径对膨胀土强度没有显著的弱化或者是强化作用,相同破损面积的试样之间也未表现出相似的强度和变形特征;揭示了既有破损对土体峰值强度的影响与土体的含水率密切相关.试样整体表现出先剪缩后剪胀的特性,但随着围压的提高,剪缩阶段明显缩短;从破坏形态可以看出,随着围压的提高,裂隙长度变短、倾角变小,说明围压对既有裂隙的扩展有明显的抑制作用.
Three groups of 15 specimens of one-dimensionally damaged expansive soil with different diameters were tested for triaxial shear tests with net confining pressures of 50, 100 and 150 kPa, respectively. One-dimensional cylindrical holes with a low water content (w = 7%) were investigated. The results show that, different from the conventional soil moisture content (about 20%), the damaged hole diameter has no obvious weakening or strengthening effect on the strength of expansive soil. , And no similar strength and deformation characteristics were observed between the specimens with the same damaged area. It is revealed that the influence of the existing damage on the soil peak strength is closely related to the soil moisture content. However, with the increase of confining pressure, the stage of shrinkage and shrinkage is obviously shortened. It can be seen from the failure mode that with the increase of confining pressure, the crack length becomes shorter and the dip angle becomes smaller, which shows that the confining pressure can expand the existing crack Obvious inhibitory effect.