关键词: 冻结压力, 广义开尔文流变模型, 冻结法凿井, 冻结壁, 外层井壁

Abstract: Freezing pressure is an important basis for the design and calculation of the outer wall structure of shaft sinking by freezing method in deep alluvium. On the basis of uniaxial creep test of frozen soil, the generalized Kelvin rheological model and the elastic-viscoelastic correspondence principle were adopted to establish the viscoelastic equation of displacement field of frozen wall. Then, the mathematical expression of the freezing pressure acting on the outer shaft lining is deduced by considering the interaction among the frozen wall, the outer shaft lining and the peripheral unfrozen soil. Calculation results show that 1) the calculation value by theoretical formula and from mean measured value of the freezing pressure show a big difference(about 0.5 MPa) in the first ten days after the construction of outer shaft lining masonry; 2) the freezing pressure tends to be stable after 20 days, and the absolute value of the difference between the two is less than 0.2 MPa. In a word, the absolute deviation between the theoretical and calculated values of freezing pressure is less than 10%. The theoretical calculation formula of freezing pressure is quite practical and it could provide basis for the structural design of outer shaft lining of freezing well.

Key words: freezing pressure, generalized Kelvin rheological model, freezing sinking method, frozen wall, outer shaft lining