ABSTRACT
Liquid nitrogen or brine freezing, both technologies were successfully used on Berlin sites during the last decade of building activities. In any way a water-table near the surface with non-stable sand formations demands special construction techniques for deep excavations. Problems with groundwater can safely be solved by artificial ground freezing. In the paper the technical aspects of freezing concerning caisson SK1 of Fernbahntunnel for German Rail are focussed. Here a temporary ice-wall of about 5,000 m3 formed by brine freezing has guaranteed a water-tight shelter during assembling the full-face tunnelling machinery till end of 1999.
