Analysis of Video Images Obtained during Cone Penetration Testing

One of the ways to enhance the efficiency of the cone penetration testing process is to mount modules behind the cone. In this way, the test will not only generate the standard CPT data (i.e., cone tip resistance, sleeve friction, and dynamic pore water pressure) but also the data obtained by the module pushed into the soil together with the cone. While for certain modules, it is common practice to analyze the acquired data extensively (e.g., the seismic module), for other modules, this is not necessarily the case. A good example of the latter is the video module when it is deployed with visible light, in which case, the analysis is typically limited to viewing the recording and adding observation notes. During the recent TRIM4 research project, the video module was deployed, and initial attempts were made to identify the soil type and to determine the grain size distribution using the video images. This approach mitigates the effect of the CPT data reflecting changes in soil strength behavior before a layer is actually penetrated by the cone. In this paper, the authors will describe the analysis options they have identified for the video recordings.