The Experimental Study Of Vertical Wave Forces Acting On Perforated Caisson On Open Bedding

In the 21st century, with the emergence of economic globalization, the large tonnage of LNG, the high-throughput deepwater dock, and projects of ultra-long-distance bridges, traditional marine buildings have not adapt to new project requirements and thus can not meet this urgent need. The perforated caisson has a good application prospect and plays a vital role in the development of the marine industry. There have been many systematic researches, made by both domestic and foreign researchers, on the structure of perforated caissons and their dynamic characteristics. For foundation with high quality, the form of open bedding could be applied, that is the height of bedding being obviously higher than that of the seabed, in order to reduce the height of perforated caissons and to further save costs. As a result, the existence open bedding and the local changes in seabed boundary conditions, will certainly affect the waves in front of perforated caissons. However, the systematic research on reflection coefficients and wave forces under influence of and their computational methods in practical engineering are relatively few, so it becomes imperative to take a systematic research on the perforated caisson with rubble foundation.In this paper, through two-dimensional physical model tests, a systematic research on wave forces, arms and torques on perforated caisson with open bedding under regular and irregular waves has been introduced and comparisons have been made to data of perforated caisson without open bedding under the same experimental conditions. The physical model tests were carried out in the wave tank for suspension material test at the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. The test models were designed to consider different influences of the width of wave absorbing room, the porosity and the height of bedding; in order to facilitate analysis and comparison, the solid conventional structure and the perforated caisson each with low and middle foundation were tested respectively.Based on single-dimensional correlation analysis, the relationships between influence factors, such as width of wave absorbing room, the porosity and the height of bedding, etc., and the total horizontal force and the total vertical force were identified. The empirical formulae of these relationships were also presented for theoretical study and practice by use of the Ordinary Least Square Estimation. The resulting expressions were simple, intuitive and easy to calculate; the results were in good agreement with the experimental data; and thus could provide valuable reference to further research and engineering design for perforated caisson.With the rapid development of computing capacity, the Artificial Intelligence and Fuzzy Theory are increasingly widely used. Artificial neural networks are a class of intelligent bionic model based on physiology, and composed of nonlinear adaptive dynamic system with a large number of processing units; it possesses good capabilities of self-organized, powerful learning, fault tolerance and anti-jamming. The present paper also analyzed the obtained experimental results and compared the fitting empirical formulas with the use of neural network analysis.