Issue 61

A. Kostina et alii, Frattura ed Integrità Strutturale, 61 (2022) 1-19; DOI: 10.3221/IGF-ESIS.61.01

Figure 12: Effect of N un on pore pressure variation.

Figure 13: Decrease in pore pressure at the hydro-observation well HW2 due to a cryogenic suction.

Aside from the material properties, the pore pressure inside of a frozen wall can also depend on a radius r of the freezing wells location. Fig. 12 illustrates the effect of the freezing с ontour radius on pore pressure variation. It can be seen that a decrease in the radius leads to an increase in the pore pressure inside the frozen wall. Therefore, freezing wells located at the larger radius provide fewer values of the pore pressure. Commonly, the freezing wells are drilled with a substantial vertical deviation, which can reduce or enlarge the radius of the freezing contour. Thus, drillhole deviation also can play a significant role in the pore pressure variation.

Figure 13: Effect of the freezing contour radius r on pore pressure variation.

The conducted study has illustrated the strong dependence of pore pressure evolution on material properties of the soil as well as freezing conditions. On the one hand, the obtained results have shown that earlier rise in pore pressure level in HW1

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