饱水砂层中结构的融沉附加力研究

在试验研究的基础上，探讨了饱水砂层的竖向冻结及融化过程土中结构切向受力的变化．试验结果表明，冻结饱和砂土融化过程可分为负温升温、相变和自由水温升３个阶段；与此对应，融化沉降过程可分为开始、急降和缓降３个阶段；而模型结构切向应力则经历了上升、陡降和缓降３个过程；最终模型受有切向融沉压缩附加应力．这对于进一步研究季节性冻土中的结构受力、冻结井井壁应力历史以及井壁裂漏颇有意义．

An Extra-force on a Structure Due to Thaw Settlement of Saturated Sand

The variation of tangential force on a structure in the processes of vertical freezing and thawing of saturated sand is discussed in this paper based on an experiment. The experiment shows that there are three phases of the thawing process of a frozen saturated sand: rising of a subzero temperature, phase changing and temperature rising of free water. Correspondingly, the thaw settlement process can be distinguished into three stages: initial, rapidly sinking and slowly sinking. The tangential force on a model structure also experiences corresponding three stages: increasing, rapidly decreasing and slowly decreasing. Finally the model structure is exerted an extra-tangential force due to thaw settlement. The result is significant for studying the load on structure in seasonally forzen ground area, the stress process of frozen wall as well as the fracturing and penetrating of shaft lining.