PROPAGATION OF HARMFUL MATERIALS AT TUNNEL ENTRANCES

SCHADSTOFFAUSBREITUNG BEI TUNNELPORTALEN

THE OBJECT OF THE WORK IS TO OBTAIN DATA FOR CALCULATING THE SPREAD OF HARMFUL MATERIALS FROM MOTOR VEHICLES AT TUNNEL ENTRANCES AND VENTILATION STATIONS, TAKING ACCOUNT OF BOUNDARY CONDITIONS. A NEW METHOD OF CALCULATION IS TO BE DEVELOPED WHICH CAN ALSO BE APPLIED TO COMPLICATED LAND FORMS. IN ORDER TO KEEP THE WORK PRACTICAL, STUDIES HAVE TO BE CARRIED OUT AT EXISTING TUNNELS. SINCE HOWEVER FULL SCALE MEASUREMENTS ARE VERY EXPENSIVE AND DEPEND ON LOCAL TOPOGRAPHIC FEATURES AND ON WEATHER CONDITIONS, AND ARE THUS ONLY VALID FOR THE TUNNEL EXAMINED, THEY ARE TO BE RESTRICTED TO A MINIMUM. FOR REASONS OF COST THE FIELD TESTS ARE BEING UNDERTAKEN IN THE FORM OF SMOKE INJECTIONS AND THE FILMING OF THEIR PROPAGATION. IT IS VERY EFFECTIVE TO DETERMINE THE PROPAGATION OF HARMFUL MATERIALS NEAR TUNNEL ENTRANCES BY MEANS OF MODEL TESTS, IN WHICH CHARACTERISTIC ENTRANCE SHAPES CAN BE CONSIDERED. IT IS POSSIBLE TO DETERMINE CRITICAL SHAPES AND EXCLUDE THEM FROM PROJECTED TUNNELS.