IN-SITU AND MODEL STUDIES ON THE INFLUENCE OF THE SHAPE OF TROUGH SECTIONS, EARTH WALLS AND HOUSING UNITS ON PROTECTION AGAINST ROAD TRAFFIC NOISE

FREIFELD- UND MODELLUNTERSUCHUNGEN ZUM EINFLUSS DER FORMGEBUNG VON TROGSTRECKEN, ERDWAELLEN UND HAEUSERZEILEN AUF DIE SCHUTZWIRKUNG GEGEN STRASSENVERKEHRSLAERM

TO COMPLETE METHODS OF CALCULATING THE PROTECTING ACTION OF WALLS, THE EFFECT OF THE FOLLOWING PARAMETERS ON THE UMBRELLA ACTION OF NOISE PROTECTION DEVICES IS TO BE EXAMINED ON MODELS AND IN SITU: (1) - CROSS SECTIONAL DESIGN OF TROUGH SECTIONS, PARTICULARLY THE INCLINATION OF THE TROUGH WALLS AND NOISE ABSORBING CLADDING OF THE WALLS; (2) - SLOPE INCLINATION, VEGETATION, CROWN SHAPE AND CROWN WIDTH OF EARTH WALLS; (3) - RATIO OF HEIGHT TO THICKNESS OF NOISE UMBRELLAS, PARTICULARLY OF HOUSING UNITS AND DOUBLE WALLS. IN MODEL STUDIES OF THE PROPAGATION OF TRAFFIC NOISE IN THE REGION OF TROUGH SECTIONS, MEASUREMENTS OF THE SPREAD OF THE NOISE DIRECTLY FROM THE TROUGH SECTIONS WERE MADE ON MODELS. THE EFFECT OF THE TROUGH STRUCTURE ON THE REDUCTION OF THE MEAN LEVEL OF TRAFFIC NOISE WITHIN THE TROUGH WAS EXAMINED, AS WAS THE EFFECT OF AUXILIARY MEASURES (NOISE UMBRELLAS ON THE RETAINING WALLS OF A TROUGH, PARTIAL COVERING OF THE TROUGH, AND A COMBINATION OF THE TWO) ON THE PROTECTION ACTION OF TROUGHS.