2023 Volume 18 Issue 3 Pages 299-315
In order to solve the problems related to subsurface cavities in urban areas, a joint research project between industry, government and academia from 2018 to 2020 was carried out. It has analysed existing cavity data, conducted laboratory model experiments, numerical analysis, full-scale field tests and cavity monitoring on the road, and attempted to develop a "series of rational processes for investigation planning, cavity exploration, collapse risk diagnosis and cavity repair". Based on the analysis of the formation and expansion mechanisms and actual conditions of cavities, a cavity potential map, a collapse risk assessment index and a menu of cavity repair and prevention measures were developed. Here, an overview of the cave-in prevention solution and a full-scale field test are reported. A full-scale test road with artificial cavities was constructed and loading tests were conducted on the road surface to elucidate the cavity behaviour in order to develop a cave-in hazard assessment and repair method that takes the road structure into account.
