A very few literature exists up to now analysing force development acting on perforated caisson and presenting liable tools for determination of design parameters. This paper based on 2D model tests presents quantification of the distribution of forces bearing on the different faces of the caisson and shows effect of phase difference in development of total peak force. Comparison is made between data of model tests and results obtained by calculation of total peak forces using Takahashi method. Field measurement recorded on Dieppe breakwater give an illustration of the force development mode on the structure.
INTRODUCTION A very few literature exists up to now in the particular field of analysis and determination of horizontal forces acting on perforated caisson. The present work, performed within the framework of MAST III- PROVERBS, is based on 2D model tests as well as on feed back from field measurement at Dieppe (France). It aims to bring a contribution in the improvement of the common knowledge and design of this kind of structure. 2D MODEL STUDY OF HORIZONTAL FORCES Description of 2D model tests Model tests were achieved in 25 m long wave flume (0.80m x 1.00m x 25.0m). The model is a perforated caisson, representing Dieppe breakwater scaled at 1/25, put on a flat bottom. Chamber width is B= 54 cm and perforations are due to circular holes φ 40 mm giving total porosity of perforated wall ε = 0.28. Seven wave characteristic sets were applied using monochromatic wave generation. Wave periods vary from ls to 7s (5s to 35s in prototype) and wave heights vary from 2 cm to 20 cm (0.5 m to 5.0 m in prototype). Two water depths were used in the wave flume d= 40 cm and d= 50 cm (respectively 10 m and 12.50 m in prototype).