ABSTRACT
Road cave-ins associated with hidden cavities are one of key issues in road maintenance. Field model tests were carried out to develop and improve methods of detection, diagnosis, and repair of hidden cavities at the prototype scale test road, 30 m long and 6 m wide. Hidden cavities were made artificially by burying bags filled with fine gravel in well-compacted base course layers. Fine gravel was removed by a vacuum cleaner after the completion of the surface course. FWD tests and plate loading tests were carried out to investigate stability of hidden cavities in base course. A series of laboratory model tests was also carried out to investigate the effect of type of geosynthetics and their depth in the base course on the stability.
