Experimental and numerical study of submarine pipeline response to hooking loads

摘要

Hooking of anchors or trawling gear in submarine pipelines can cause catastrophic consequences on life and property. To quantify the consequences of these events and thus to mitigate this risk and provide a reference for submarine pipeline safety design, the failure mechanism and response of pipelines subjected to hooking loads is investigated experimentally and numerically. The experiment is first carried out to give an initial insight into pipeline response and then is used for validation of the numerical approach. Then the validated numerical model is used for studying the effect of boundary conditions, wall thickness and internal pressure on pipeline response and failure mechanism. Finally, the pipe-soil interaction is modeled and the pipeline response considering embedment depth, soil properties and friction is studied. The results show that the pipeline failure pattern differs under different boundary conditions. With the increase in embedment depth, the ultimate hooking force increases due to the restriction from the soils. The soil strength and ultimate hooking force are in a nonlinear relationship. The effect of friction is less significant for soft clays.