Abstract: The influence of the construction machinery eccentric load on trench stability was studied by centrifuge model tests simulating the process of trench excavation.It was shown that the failure mechanism agreed well with that under the central load of construction machine.Therefore,the simplified expression for the upper-bound of excavation depth under the central load could be applied to that under the construction machinery eccentric load.The validity of the results from the simplified expression for the upper-bound solution was confirmed by comparing with the centrifuge test results.It was indicated that the influence of eccentricity on excavation depth increased with the increase of contact pressure.