Risk Mitigation for Punch through of XXL Monopiles – MPM Validation and Field Observations

Abstract Uncontrolled punch through during set down of an XXL monopile can be disastrous for a (floating) installation vessel. An analytical model was developed to predict punch through capacity for monopiles on sand-over-clay conditions. Material Point Method (MPM) analyses were used for validation of the model and a proposed risk mitigating measure that allows for a controlled punch through, with reduced risk to vessel and equipment. Field observations from construction of a wind farm off the US East coast allowed for full scale validation of the model and reflect the effectiveness of the risk mitigating measures taken.