关键词: 动三轴试验, 黏性土, 动强度, 动剪切模量, 阻尼比

Abstract:

To study the influence of soil disturbance on the soil dynamic characteristics, undisturbed and remolded cohesive soil samples from various depth at the Baohe District of Hefei were collected for the laboratory study by using the GCTS STX-100 two-way vibration triaxial testing system. Based on the dynamic triaxial test results, the following conclusions are obtained: (1) Under the same confining pressure, the difference of the dynamic characteristic parameters (maximum dynamic stress τ_dmax, maximum dynamic shear modulus G_dmax) of the undisturbed and remodeled cohesive soil samples vary with the increase of sampling depth. It gradually increased; under the low confining pressure (50kPa), the τ_dmax and G_dmaxof the undisturbed samples and the remodeled samples had little difference, and the relationship curves tended to overlap. With the increase of the confining pressure, the relationship curve is rapidly separated, the τ_{dmax and}

G_dmax of the undisturbed samples are larger than those of the remolded samples, and the increase range gradually increases with the increase of the confining pressure. When the confining pressure reaches 300kPa, the deviation range can reach more than 30%; (2) The damping ratio λ_d of the undisturbed samples and the remolded samples decreases with the increase of the confining pressure under the same dynamic strain; λ_dmax is between 0.2-0.3; (3) The dynamic strength and the dynamic shear modulus of the soil decrease due to the disturbance of the soil.

Key words: Dynamic Triaxial Test, Clay Soil, Dynamic Strength, Dynamic Shear Modulus, Damping Ratio