INFLUENCE OF GROUNDWATER SEEPAGE ON ARTIFICIAL FREEZING OF ROCK MASS

Investigation of the effect of horizontal groundwater seepage in a rock mass subjected to artifi cial freezing on the parameters of a frozen wall formed around a projected shaft is carried out. For this purpose, a mathematical model of coupled heat and mass transfer in a watered rock mass subjected to freezing is formulated, and numerical multiparametric simulation of the formation of frozen wall under the conditions of groundwater seepage with variable rate has been made. A sandstone layer for the conditions of Petrikovo deposit of potash and rock salts is predominantly considered in the work. An analysis of the results has shown that the infl uence of groundwater fl ow on the frozen wall thickness begins at seepage rates of about 50 mm/day. In this case, the infl uence of the groundwater fl ow on the temperature fi eld of the rock mass begins earlier, at seepage rates 10–25 mm/day. Three mechanisms of the frozen wall dynamics on increase in the rate of groundwater seepage rate are determined: shift, deformation, and loss of continuity. Corrections for the frozen wall thickness in the presence of groundwater fl ow for a sandstone layer for the interval of seepage rates from 50 to 150 mm/day have also been established.
   
Author:  M. A. Semin, L. Yu. Levin, and O. S. Parshakov
Keywords:  frozen wall, shaft, artifi cial ground freezing, heat and mass transfer, groundwater seepage, numerical simulation
Page:  45