冻结过程中冰透镜体生长规律研究

Study of the ice lens growth during the freezing process

针对现有冰透镜体判断准则存在的不足,文章采用土体抗拉强度作为分离强度,不仅明确了分离强度的物理意义,而且还考虑了土体强度对分凝冰形成的影响。依据考虑土体变形的冻胀模型,对冰透镜体生长规律进行了分析。结果表明:冰透镜体的形成位置受温度边界的影响明显。冰分凝量受水分迁移量的制约,导致分凝冰的产生过程有3个阶段:未形成分凝冰、形成少量不连续的分凝冰、末分凝冰生长及发展。冻胀主要由末分凝冰的发育程度控制。冰分凝量随着荷载的增大呈现指数式衰减。

Considering the limitation of existing ice lens forming principles,the tensile strength was used as the separation strength in this paper. This method not only definite the physical meaning of separation strength,but also considered the effect of soil properties on segregated ice lens. On the basis of frost heave model,the ice lens growth was analyzed. Results show that the position of ice lens is influenced by temperature boundaries,and the amount of ice lenses is controlled by moisture migration. Due to the limitation of water supply,the process of ice lens growth can be divided into three stages: no ice lens formation,a small amount of discontinuous ice lens formation,the final ice lens growth. The frost heave is mainly control by the development level of the final ice lens. The increase of overburden pressure causes an exponential decreased in the amount of segregated ice.