ABSTRACT
This communication focuses on the behaviour of buried steel pipes submitted to surface loading such as traffic loading. A laboratory small-scale model has been developed to better understand the soil-pipe interaction. The final objective is to assess the existing design method, and develop them if required.The test set-up consists in a rigid tank with metric dimensions, filled with sand. Real steel pipes are scaled down at 1/3 on the length, leading to the relevant use of 100 mm diameter aluminium pipes. No gas pressure is simulated within the pipes, as it is then an unfavourable condition regarding the effect of surface loading on the pipe. Surface loading with up to 1000 cycles is applied using a vertical actuator acting on a plate. The procedure includes an extensive instrumentation, in particular strain gauges on the pipe and inner displacement sensors,. The experimental campaign permitted to assess the effect of the pipe radial stiffness (by varying the pipe thickness) on the pipe response due to monotonic then cyclic surface loading. The small-scale experimental results were upscaled at the real structure scale and compared to the existing design practice, to highlight its limits and the importance of taking the soil-pipe interaction into account.
