Analyses of strength and deformation of an artificially frozen soil wall in underground engineering

In general, an excavated foundation places the surrounding soil in a state of unloading. By simulating the consolidating and freezing processes of a foundation and then carrying out shear tests under loading and unloading, this project compared changes of yield strength and failure strain under two stress paths and analyzed reasons for the frozen wall failure. It is found that the yield strength under unloading is obviously less than that under loading and the difference of the yield strength between the two stress paths increases with an increasing pressure, but the failure strains under the two stress paths do not differ greatly. With the decrease of temperature, the yield strength and failure strain increase, but the yield strength and failure strain under unloading are obviously less than that under loading, and their difference also increases with a decreasing temperature. This is one of the main reasons for the frozen wall to collapse and the freezing pipes to break with the increase of excavating depth.