Abstract: Trial pit test is a standard method for evaluating rockfill compaction in dam construction. The advent of 3D laser scanning technology offers a rapid, accurate alternative to the traditional water filling method for measuring the pit’s volume. This study develops a new method that integrates data acquisition, registration, and fast volume calculation using 3D laser scanning. Tested against the standard model and a laboratory experiment, the method captures the irregular distribution of rockfill particles effectively; Optimizations in large-scale in-situ tests have achieved volume measurement errors roughly within 5%. Field applications in dam projects further validate the method's efficiency, significantly reducing inspection time and having the potential to replace traditional methods.

Key words: rockfill dam, test pit method, volumetric measurement, 3D laser scanning, 3D point cloud