粘性原状土起动切应力与物理力学指标的关系

Relation of starting shear stress and physical and mechanical indexes of cohesive undisturbed soil

通过对中运河、长江长兴岛、淮河入海水道等河道原状土样起动试验,认为各河道土质由于其形成条件、土质结构等方面存在差异,即使具有相近的物理力学特性,其起动临界条件也不尽相同。而对同一条河流而言,起动临界条件与物理力学指标之间则存在明显的规律性:即对淤泥质粘土,起动临界条件随抗剪强度的减小而增大,随含水量的增大而减小;粉质粘土的起动临界条件最小,与抗剪强度、含水量呈非线性关系;粘土起动临界条件则随抗剪强度、含水量的增大而增大。

Through the test of the undisturbed soil samples from Zhongyun River, Changxing Island of Yangtze River, and the water channel of Huaihe River to sea, it is considered that the critical starting condition for soil in different channes are different because of the difference of the formation conditions, qualities and structures, though the physical and mechanical properties of soil is similar. However, for the same river, the obvious regularity exists in critical starting condition and the physical and mechanical indexes： the critical starting condition strength and decreases with the increase of the moisture and the relation of the clay, the shear s cohesive soil increases with the increase trength and the of the muddy cohesive soil increases with the decrease of the shear content; the critical starting condition of silty clay is the minimum, moisture content is nonlinear; and the critical starting condition of the of the shear strength and the moisture content.