A SURVEY OF DYNAMIC METHODS OF TESTING ROADS AND RUNWAYS

THIS IS A STATE OF THE ART STUDY OF VIBRATIONAL ROAD TESTING. THE VIBRATIONAL METHOD OF TESTING ROADS ORIGINATED IN GERMANY WHERE, BEFORE WORLD WAR II, MECHANICAL VIBRATORS WERE USED TO INVESTIGATE THE MECHANICAL PROPERTIES OF DIFFERENT TYPES OF SOIL. DURING AND AFTER WORLD WAR II, FURTHER DEVELOPMENTS OF THE TECHNIQUE WERE MADE BY THE ROYAL DUTCH SHELL CO.'S LABORATORY AT AMSTERDAM, AND THE METHOD WAS APPLIED TO TESTING ROADS AND RUNWAYS. THE DYNAMIC STIFFNESS OF THE CONSTRUCTION WAS DEDUCED FROM THE APPLIED VIBRATORY FORCE AND THE RESULTANT AMPLITUDE OF VIBRATION. TESTS ON A VARIETY OF ROADS INDICATED THAT HIGH VALUES OF THE STIFFNESS WERE ASSOCIATED WITH STRONG FORMS OF CONSTRUCTION, AND LOW VALUES WITH WEAK ONES. THE ULTIMATE OBJECTIVES OF THIS FORM OF NONDESTRUCTIVE TEST ARE TO PREDICT THE PERFORMANCE OF ROADS UNDER TRAFFIC AND TO DETERMINE WHERE AND WHEN FAILURE OF THE CONSTRUCTION IS BEGINNING. TESTING TECHNIQUES TO THESE ENDS HAVE BEEN DEVELOPED RECENTLY IN GERMANY. THE BRITISH ROAD RESEARCH LABORATORY HAS BEEN STUDYING THE VELOCITY OF PROPAGATION OF VIBRATIONS IN LAYERED CONSTRUCTIONS USING ELECTRO-MECHANICAL VIBRATORS COVERING A MUCH WIDER FREQUENCY RANGE THAN IS POSSIBLE WITH THE ROTARY MACHINES NORMALLY EMPLOYED. THE RELATIONS OBTAINED BETWEEN VELOCITY AND FREQUENCY ARE BEING STUDIED TO DEDUCE THE ELASTICITIES AND THICKNESSES OF THE LAYERS PARTLY TO ASSESS THE QUALITY OF THE CONSTRUCTION AND PARTLY TO OBTAIN DATA WHICH MIGHT BE LATER EMPLOYED FOR PAVEMENT DESIGN. THE APPLICATION OF VIBRATIONAL TESTING TO PAVEMENT DESIGN IS STILL IN ITS INFANCY AND IT IS TOO EARLY YET TO DECIDE WHETHER OR NOT SUCH A DESIGN TECHNIQUE WILL ULTIMATELY BE POSSIBLE. /AUTHOR/

Media Info

  • Monograph Title: Non-destructive dynamic testing of soils and highway pavements
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00206922
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 19 1994 12:00AM