Model tests on chain-soil interaction of anchor pile for taut mooring system through transparent sand

Abstract

The pile response of taut mooring systems considering chain-soil interactions remains unclear. In this study, model tests on the performance of anchor piles and the surrounding soil displacement field were conducted using transparent sand. Cyclic motion was imposed at the top end of the chain. The effects of pad eye location (z), motion velocity (v), motion amplitude (A), and amplitude increment (Ai) are discussed. In the constant-amplitude tests, the soil displacement caused by chain motion was apparent near the dip-down point, and the soil displacement increased with z and A. The maximum chain tension decreased owing to chain-soil interactions. The maximum tension with z = 0.55L and 0.67L (where L is the pile length) increased 9% and 15%, respectively, compared with that with z = 0.40L, and the maximum tensions at A = 80 and 120 mm decreased 15% and 29%, respectively, of that at A = 40 mm. In the incremental-amplitude tests, soil displacement was evident around the dip-down point and pile. The maximum tension during each cycle increased almost linearly with the number of cycles before pile failure, and the maximum tension during the entire test increased with z and v.