Centrifuge modeling of subaqueous and subaerial landslides impact on suspended pipelines

摘要

Subaqueous and subaerial landslides pose a significant threat to pipelines. This paper discusses the drag forces resulting from the impact of a portion of an intact submarine and subaerial landslide on a pipeline. Ten geotechnical centrifuge experiment tests were conducted. Eight of which simulated a submarine glide or out runner block impact on pipeline, and two modelled that of subaerial. At 30 times of Earth's gravity, the prototype scale of the clay blocks used in the tests measured about 4.5 m high and 12.0 m long. The undrained shear strengths ranged from 4 to 7 kPa for the submarine tests and 9 to 13 kPa for the subaerial. The clay blocks impacted the model pipes, normal to its axis, at velocities ranged from 0.1 to 1.3 m/s. The shear strain rates (defined as the ratio of velocity over pipe diameter) in the experiments ranged from 10 to 137 reciprocal second. A method is presented to estimate the drag forces on a suspended pipeline caused by a glide or out-runner block in submarine scenario.