DETERMINATION OF THE RELATION BETWEEN GEOMETRIC DEVIATIONS FROM THE DESIRED SURFACE AND TRAFFICABILITY

ERMITTLUNG DES ZUSAMMENHANGES ZWISCHEN GEOMETRISCHEN ABWEICHUNGEN VON DER SOLLFLAECHE UND DER BEFAHRBARKEIT

THE OBJECT OF THE RESEARCH PROJECT IS TO DEVELOP A METHOD BY MEANS OF WHICH THE TRAFFICABILITY OF A SURFACING CAN BE CHECKED DURING CONSTRUCTION. IN ACCORDANCE WITH CURRENTLY VALID ACCEPTANCE SPECIFICATIONS, FOR COMPARISON PURPOSES, A 4M LONG BASIC PANE OR LINE IS TO BE USED, RELATIVE TO WHICH THE EVENNESS IS CONSIDERED IN THE FORM OF MAXIMUM PIER HEIGHTS. THE SUBJECTIVE IMPRESSION OF THE TRAFFICABILITY OF A ROAD IS HOWEVER NOT FORMED WITHIN SUCH SHORT SECTIONS; RATHER, A SUMMARY SENSITIVITY VALUE IS FORMED OVER A LARGER SECTION DEPENDING ON DRIVING SPEED. EXPERIENCE HAS SHOWN THAT ROAD SECTIONS AT LEAST 100 METRES LONG HAVE TO BE SEEN AT A TIME. FOR THE CONTROL OF THE CONSTRUCTION WORK DURING THE PROCESS OF MANUFACTURE IT IS NECESSARY TO DO THIS ON AS SHORT SECTIONS AS POSSIBLE, SINCE FOR PURELY TECHNICAL REASONS A NECESSARY SUBSEQUENT IMPROVEMENT MAY ONLY TAKE PLACE WITHIN LIMITED TIMES. IN ASSOCIATION WITH THE WORK DONE UNDER RESEARCH PROJECT NO. 4.51 (IRRD NO.032316), IT IS INTENDED TO CARRY OUT STUDIES TO COMPARE THE ACTUAL PROFILE OF SEVERAL SELECTED SECTIONS WITH THE TRAFFICABILITY COEFFICIENT. IT IS INTENDED NOT ONLY TO CONSIDER AMPLITUDES, BUT TO INCLUDE SPECTRAL DISTRIBUTIONS. IF THERE IS A RELATION BETWEEN TRAFFICABILITY ON THE ONE HAND AND CERTAIN AMPLITUDE AND/OR FREQUENCY DISTRIBUTIONS ON THE OTHER HAND, AN ATTEMPT WILL BE MADE IN A SECOND STAGE TO CALCULATE THE MINIMUM LENGTH OF A TEST SECTION ON THE BASIS OF THESE RELATIONS. 25 SECTIONS OF ROAD AS NEW AS POSSIBLE, AND EACH 200M LONG, ARE SELECTED FOR THE STUDIES, WHERE BOTH THE TRAFFICABILITY COEFFICIENT AND THE TRUE GEOMETRIC PROFILE ALONG THE MEASURING LANES OF THE LONGITUDINAL PROFILE INCLINOMETER ARE BEING MEASURED BY MEANS OF THE STUTTGART PROFILOGRAPH, AND THE RELATIVE PROFILE BY MEANS OF A 4M LATH . THE CALCULATIONS COMPRISE DETERMINATIONS OF PIER HEIGHTS BY SENSING OF THE CURVES AND BY MEANS OF FREQUENCY DISTRIBUTIONS, USING FOURRIER ANALYSIS. THE SENSING OF THE PRESCRIBED PROFILE CURVES IS BEING CARRIED OUT WITH EXISTING AUTOMATIC EQUIPMENT.