Monitoring of dynamic compaction using topographic survey

Abstract

This paper demonstrates how a topographic survey can be used as a tool to assist in assessing dynamic compaction in uncontrolled fill sites. A full-scale dynamic compaction trial was carried out during which a topographic survey was used to monitor the change in ground level immediately after the application of each pass during the dynamic compaction process. The topographic survey data has been used to develop spatial plots of the print-to-heave volume ratio. For the primary and secondary passes the spatial plots provide an indication of the consistency of the ground response to dynamic compaction, delineating areas of low print-to-heave volume ratio, where the soil is relatively dense, and areas of high print-to-heave volume ratio, where the soil is relatively loose. Topographic surveys could be used in the quality assurance and quality control processes for dynamic compaction. For example, the spatial plot of print-to-heave volume ratio could be used to locate additional geotechnical investigations, to delineate areas of different compaction levels in uncontrolled fills, and to identify areas where a tertiary pass is and is not required.