Abstract: The mooring system of the tube section of immersed tunnel is the prerequisite guarantee to resist the force of water flow and provide accurate positioning during the installation of the tube section, while the overall structural motion response and anchor cable force under the mooring system affect the safety and economy of the construction phase. This paper takes the example of the immersed tunnel project in Ruyifang, Liwan District, Guangzhou City, and uses the hydrodynamic simulation software AQWA based on potential flow theory for calculation and analysis. According to the actual data for the three-dimensional finite element modeling of the structure, the mooring system was first analyzed in the frequency domain, and then the time-domain coupling analysis was added, and the joint effect of JONSWAP wave spectrum and water flow was considered to study the effect of wave incidence angle, environmental combination mode and other factors on the motion response and anchor cable force under this system. The calculation results show that the tube section fluctuates in the low frequency region, and gradually stabilizes with the increase of frequency; the effective wave height has a great influence on the motion response of the tube section; the maximum value of the anchor cable tension occurs when the wave incidence angle is $ 90^{\circ} $ under this system.
Keywords: immersed tunnel; irregular wave; mooring system; hydrodynamic analysis; motion response