Soil Surface Deformation Measurement Using Photogrammetry Based on a Consumer-Grade Camera

Photogrammetry for measuring soil surface movement has gained popularity in recent years. This technique involves placing coded targets and ground points on the soil surface and capturing images before and after the movement, enabling precise measurements. This study explores the effectiveness of using a consumer-grade camera for geotechnical soil surface heave measurement compared to conventional methods, such as dial gauges, during laboratory pullout tests. The laboratory pullout tests were conducted by pulling out an anchor driven into a soil box consisting of sandy lean clay. The dimensions of the soil are 1 m x 1 m x 1 m (3.28 ft x 3.28 ft x 3.28 ft). Digital dial gauges were positioned on the soil surface to measure surface heave during pullout tests. The consumer-grade camera was used to capture soil surface images before and after each pullout test. The captured images were then processed using the photogrammetric software Agisoft Metashape Professional to obtain soil surface displacement due to the anchor pullout. The acquired displacement of the soil surface from photogrammetry was compared with readings obtained from dial gauges. Results demonstrate the successful application of photogrammetry in obtaining accurate measurements of heave. In addition, heave patterns related to different anchor embedments were analyzed based on photogrammetric images. This study aids in predicting potential soil heave occurrences, expanding the potential applications of photogrammetry in geotechnical engineering.