Investigation of the peak punch-through capacity of spudcan on sand overlying spatially variable clay

Abstract

Accurately estimating peak penetration resistance in punch-through sensitive deposits is crucial for managing risks during jack-up rig installations. While offshore clays exhibit significant spatial variability, necessitating consideration of spatial variability in predicting peak penetration resistance. This study investigates the effects of spatial variability of underlying clay on the failure mechanism and magnitude of peak penetration resistance during punch-through incidents. The Modified Linear Estimation Method was used to generate three-dimensional random fields, incorporated into coupled Eulerian Lagrangian finite element analyses to simulate spudcan penetration from the ground surface. Results show that while spatial variability has an insignificant effect on the failure mechanism in the upper sand layer, it significantly alters soil flow in the underlying clay, leading to variations in peak penetration resistance. The peak penetration resistance follows a log-normal distribution, and a relationship was established between the probability of failure and the factor of safety. This study highlights the importance of considering soil spatial variability and demonstrates the significant impact of underlying clay on the failure mechanism and magnitude of peak penetration resistance during punch-through incidents, which might be helpful for the safety management of industry.