DESIGN METHOD ON DECREASING OF HEAT INSULATOR DEPTH OF ADIABATIC DOUBLE LINING IN LONG TUNNEL

Abstract

An adiabatic double lining in tunnel, in which a heat insulator was sandwiched between an outer lining and an inner one, was developed for a prevention work of icicles and frost heave of newly constructed tunnel. This paper proposes an approximate and reasonable estimation method of decreasing heat insulator depth, step by step, from portal to tunnel center according to an amplitude fluctuation of atmospheric temperature in tunnel. This also deals with temperature behabiours of a few adiabatic double linings in a long tunnel which was newly constructed, and the applicability of the proposed estimation method.