日 時 ：2025年 3月 5日（水） 15：30 ～ 17：00
講 師 ：Francesca Casini教授（Università degli Studi di Roma Tor Vergata）
講演題目：Artificially frozen soil for underground construction: Two case studies
講演内容：
Artificial ground freezing (AGF) is a temporary earth-supporting system used in a variety of engineering applications spanning from excavation in urban areas to the formation of an ice wall groundwater barrier around, e.g., the Fukushima nuclear power plant. Freezing and thawing of pore fluid within soils involves complex thermal, hydraulic and mechanical processes that can have significant mutual geotechnical interactions. For example, phase changes of pore fluid caused by temperature variations modify the hydraulic regime of the soil, which in turn induces mechanical deformation. At the same time, any change in the hydraulic and mechanical conditions influences the thermal processes by advection and changes of ice and water contents. This presentation will report the latest scientific discoveries of the thermo-hydro-mechanical behaviour of artificially frozen soils and their implication to engineering design of the thickness of the frozen wall. The first part of the presentation will focus on the fundamental behaviour of frozen soils. The interpretation of the experimental results will be based on an extension of the unsaturated soil mechanics. The second part of the presentation will report the application of AGF in two case histories, the first in urban area and the latter in the under passing of a river.