Liquefaction flow slides in large flumes

Liquefaction flow slides in sand have been investigated during an extensive experimental research programme during the period 1973-1977 on behalf of the design of the storm surge barrier in the Oosterschelde estuary. The programme included more than a hundred tests in large- and medium-sized flumes on submerged, loosely packed sand bodies. Each sand body had a horizontal surface and a very steep, supported slope as initial boundaries. Retrogressing liquefaction flow slides with high retrogression velocity and large retrogression distance occurred in several tests with very loosely packed sand. Retrogression velocities and distances in the other tests were just a fraction of those in first mentioned tests, although liquefaction occurred in some of them. The test set-up, measurements and results of the tests are described in this paper. An interpretation of the liquefaction flow slide process as a sequence of several interacting sub-processes is presented as well. Finally, tentative scaling rules are given and compared with observations.