Influence of spudcan-pile interaction on laterally loaded piles

Jack-up rigs are often operated near a permanent jacket platform for offshore gas and petroleum exploitation. A reduction in the lateral bearing capacity of adjacent platform piles could occur due to the disturbance of the soil around the footprint created by spudcan penetration and extraction. Centrifuge model tests were conducted in soft clay to investigate the lateral behaviour of piles, including a base pile and spudcan-affected adjacent piles, subjected to monotonic lateral loading. The results show that the lateral static capacity of an adjacent pile (L/D = 0.5) is reduced by 10.5% compared with that of the base pile. Obvious decreases in the soil reaction stiffness and ultimate lateral pressure occurred due to the spudcan-pile interaction and are related to the clearance and burial depth. Finally, based on the proposed modified p-y curves, which were proven to be reasonable, an engineering analysis approach is presented for evaluating the lateral bearing capacity of adjacent platform piles.