Abstract
There are many labor accidents in which workers or operators are buried under collapsed earth, or are injured when construction machinery such as a drag-shovel falls or topples over the edge of the trench during excavation. Our survey on labor accidents revealed that about 30 workers die every year in this type of accident. This study examined the stability of the trench excavation sites under the construction machinery load by the following procedures : 1) The load of construction machinery was modeled; 2) Failure behavior and depth of excavation were studied by conducting centrifuge model tests using an in-flight excavator, with the test parameters such as the magnitude of the machinery load, position of the load, etc.; and 3) The results from the upper bound solution based on the observed failure mechanism were compared with the failure mode in the centrifuge tests, and a good agreement was found.
