Improvement in Calculation of Resistance Force on Caisson Sliding Due to Tilting

The aim of the present paper is to investigate the long-term deformations of the rubble mound of a breakwater during its working life. Understanding these deformations is essential for the sliding and tilting to be able to be measured effectively. In order to do so, laboratory experiments were carried out, from which probability distribution functions of sliding and tilting were obtained for a series of three storms of similar intensity. The laboratory results were then reproduced using a computer model, which decomposed the movement of the caisson into its vertical and horizontal components. The horizontal movement uses the equation of Shimosako and Takahashi [1998] as modified by Kim and Takayama [2005], whereas for the vertical deformation the method of Esteban and Shibayama [2006] is employed. A new methodology for the calculation of the resistance force caused by the caisson tilting is proposed. The results obtained overestimate the deformation slightly during the first storm but can predict well the deformation during the subsequent storms.