Developing a Correlation Method to Determine Grout Intake Volume of Raveled Soil

Cone penetrometer tests (CPTs) have been extensively used for sinkhole geotechnical investigation, especially in regions with bedrock in deeper burial depth (such as East Central Florida). One common method to mitigate potential sinkholes is through grouting. However, the determination of grouting volume is very challenging. The sinkhole resistance ratio (SRR), developed from CPT data as an index to better understand the state of raveling and sinkhole susceptibility, can be used to help identify grouting volume potential. In this study, two approaches were taken to explore the correlation between SRR values predetermined at the existing sinkhole sites and grout intake volumes: (1) through a site-wide grouting index (GI), and (2) based on individual CPT location and localized grouting volumes. This study was applied to various sinkhole locations throughout Central and Northern Florida. Based on the dataset, approach 2 using individual CPT locations provided a better correlation between the SRR value and grout volume. Using a logarithmic trend, it was shown that as the SRR value decreased, there was an exponential growth in grout volume used.