关键词: 裂隙岩体, 渗流地层, 人工冻结壁, 冻结温度场, 交圈时间

Abstract: A numerical calculation model of fractured rock mass frozen with double hollows under the function of seepage has been set up，and the influence of the fracture aperture, the fracture inclination and the influence of the seepage velocity on the development of artificial freezing wall in seepage strata with fractured structure have been analyzed using the COMSOL Multiphysics finite-element analysis software．The results show that: 1) The larger the fracture aperture is, the longer the freezing wall closure time becomes and the larger the increase; both in the main section and the interface of frozen wall, the upstream speed of development in the frozen wall is significantly less than that of the downstream speed of development; 2) The freezing zone and isotherms of fracture angle of 0 °are symmetric about the y-axis, and the distribution of freezing temperature field for 10 °, 20 ° and 30 ° is no longer symmetrical about the y-axis, and the isotherms outside the frozen wall show “heart-shaped” distribution along the fracture inclination, ie the thickness of the frozen wall is the thickest in the downstream direction while the thinnest in the upstream direction along the fracture inclination. The influence of water seepage on the freezing temperature field distribution decreases gradually as the fracture angle increases. Under the given conditions in this paper, the seepage velocity is the main factor which influences on the frozen wall development, followed by fracture aperture and the fracture inclination.

Key words: fractured rock mass, seepage strata, artificial freezing wall, freezing temperature field, closure time