摘要
冻结压力大小是深厚冲积层冻结法凿井外层井壁结构设计计算的重要依据。在冻土单轴蠕变试验基础上,采用广义开尔文流变模型,以及弹性-黏弹性对应原理,建立冻结壁位移场黏弹性方程;然后考虑冻结壁与外层井壁及外围未冻土体的相互作用,推导出了作用于外层井壁上的冻结压力的数学表达式。计算结果表明:在外层井壁砌筑后的前10 d,冻结压力的理论公式计算值与实测结果平均值相差较大,约0.5 MPa;在20 d后,冻结压力趋于稳定,两者差值的绝对值在0.2 MPa以内。总之,冻结压力的理论计算值与实测结果的偏差绝对值在10%以内。因此冻结压力的理论计算公式是比较符合实际的,此公式可为冻结井的外层井壁结构设计提供依据。
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.
出处
《长江科学院院报》
CSCD
北大核心
2017年第11期84-88,95,共6页
Journal of Changjiang River Scientific Research Institute
基金
国家自然科学基金项目(51374010
51474004)
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
freezing pressure
generalized Kelvin rheological model
freezing sinking method
frozen wall
outer shaft lining
