Experimental studies on ice shells in Asahikawa

An ice shell is thin, and its structural material is snow-ice. It may be an efficient form of instant shelter for snowy and cold regions. This paper describes two field studies on ice domes carried out in Asahikawa. The first one is an investigation on the creep collapse of a 5-m span model under a concentrated load acting on a circular area at the apex. Normal displacements and temperatures were measured up to the collapse. Experimental collapse time was examined, introducing the classical creep buckling value of a completely spherical shell under uniform external pressure. The second study deals with both the construction technique and the creep test of a 10-m span model. The construction technique consists of: (1) inflating a membrane bag covered with rope, (2) spraying it with snow and water, (3) solidifying the snow-ice sherbet on it, and (4) removing the bag and rope for reuse. Subsequently, a creep test was carried out under snow load, and its structural behaviour up to the collapse was examined. Based on the results of these studies, the production of 20–30-m span ice shells may be practicable.