Mr Amin Rismanchian
B Sc, M Sc, MPhil
Master of Philosophy in Geotechnical Engineering, University of Manchester, Manchester, UK
Master of Science in Geotechnical Engineering, Amirkabir University of Technology, Iran
Bachelor of Science in Civil Engineering, Shiraz University (Pahlavi State University), Shiraz, Iran
- Pipe soil interaction
- Suction piles
- Soil stabilization
- Professor David White
- Professor Mark Randolph
Three dimensional modelling of pipeline buckling on soft clay
Seabed pipelines must be designed to absorb thermal and pressure-induced loading in a safe and controlled manner. The resulting expansion is often accommodated by lateral buckling, in which the thermal and pressure-induced loads are resisted by pipe-soil forces.
So far most of the research on pipeline – soil interaction was focused on the behaviour of the crown of a buckle, and very idealised events. Therefore, a holistic approach towards the whole buckle was missing. In my centrifuge tests, I model the behaviour of different sections of a buckle. In these tests the movement amplitude is up to 8 diameters and different pipe weights are studied.
In addition to these experiments, some existing data has been analysed to understand the different kinematics mechanisms during pipe-soil interaction. Finally, these data will be back-analysed using limit analysis and Finite Element methods, and used to derive generalised calculation models for arbitrary modes of pipe-soil interaction.
Pipelines are the arteries of the oil and gas industry, and are now being designed to withstand ever higher temperatures and pressures. A key challenge is to mitigate the resulting cyclic expansions, and an efficient approach is to allow the pipeline to buckle in a controlled manner.
Accurate estimation of soil resisting force is essential for the safe design of buckling pipelines. Over-estimating the soil resisting force may cause a catastrophic failure, because the buckle may advance and develop high curvatures which lead to higher bending moments than the pipe has been designed for. On the other hand, under estimating the soil resistance can also lead to unwanted structural deformations, or may impose more costs to the project by over-designing the pipe wall thickness.
Alternatively, when controlled buckling is desired, it may not occur as planned if the soil resistance is under estimated. In this case unwanted axial forces may build up within the pipe leading to buckling at an unexpected location that can cause catastrophic failure. Therefore, predicting the true behaviour of soil during lateral buckling is crucial in the efficient and safe design of pipelines.
My findings in this research are being fed directly into engineering practice, and specifically COFS’ industrial partners in the SAFEBUCK Joint Industrial Project (JIP), to design safer and more economical pipelines.
SAFEBUCK JIP, Western Australian Energy Research Alliance (WA:ERA), Australian Postgraduate Award (APA), University of Western Australia (UWA), Centre for Offshore Foundation Systems (COFS).