Characterization of single and dual SFT through a hydraulic experiment under regular and irregular waves

Abstract

Characterization of structural behaviors on a submerged floating tunnel (SFT) under various wave conditions is an important task for the realization of an emerging structure. An SFT can be designed as a single or dual section type by considering its structural, cost-effective, and constructional aspects. However, few experiments have been performed under irregular waves conditions and research on dual section SFTs is hard to find, even though this section type is considered in many preliminary designs. In this paper, single and dual type SFTs were experimentally investigated by using a 2-D wave flume. For measuring the behavior under various wave con-ditions, 16 regular waves and 5 irregular waves with different combinations of wave heights and periods were determined. Generated waves were verified, and tensile forces on mooring lines were primarily analyzed. After that, tunnel displacements and vibration characteristics were investigated to support additional reliability of the study, followed by a comparison of the structural responses with numerical analyses. It was found that the behavior of SFTs is affected by wave height, period, characteristic dimension, and that the decreased motion of dual SFTs does not mean a better result. Through the experimental study, characteristics and possibilities for realization of the SFT are examined.