A Potential Technology for Road Sinkhole Assessment: The Rolling Dynamic Deflectometer

Abstract

Abstract In urban areas, excessive underground construction, aging of underground infrastructures (e.g., water pipe leakage), or both, can create underground cavities that ultimately lead to subsidence and sudden road sinkholes. These road collapses have often been reported in metropolitan areas around the world. A quick and accurate in situ testing method is essential to prevent human life loss and damage to civil infrastructure. This article introduces potential technology for road sinkhole assessment that can continuously assess the road subsurface condition in a nondestructive manner. The Rolling Dynamic Deflectometer (RDD) is a continuous pavement deflection profiling device that evaluates the existing structural condition of pavements. As the RDD moves along the pavement, it dynamically loads the pavement, and multiple rolling sensors simultaneously measure the induced dynamic deflection of the pavement. With a soft subgrade or subsurface voids, the RDD deflection profile clearly shows peak deflections. Three RDD case studies that demonstrate its potential as a road sinkhole assessment tool are presented: (i) delineation of stiffer subgrade conditions, softer subgrade conditions, or both, along a runway, (ii) identification of areas with poor subgrade soils, and (iii) detection of subsurface voids (or anomalies) along with ground-penetrating radar.