The role of cable stiffness in the dynamic behaviours of submerged floating tunnel

submerged floating tunnel (SFT) is an innovative structural solution for waterway crossings and is based on the idea of Archimedes Buoyancy. The main structure is kept at a certain depth underwater and is placed in position by anchor/mooring cables. SFT becomes a more economical alternative for waterways compared to classical solutions such as cable-supported bridge, immersed tunnel or underground tunnel when the width and depth of the waterway are large enough. As SFT is completely submerged in water and is subjected to extreme environmental conditions such as waves, earthquakes, and hurricanes, therefore, the evaluation the dynamic characteristics of an SFT under irregular waves is a key demand from the design point of view. In this study, the responses of an SFT that is to be built in Qindao Lake of China are investigated under irregular waves. A 3D FEM model for SFT was established, the tunnel was modeled by 3D beam elements and cables were modeled by elastic catenary elements. The irregular waves were modeled by JONSWAP spectrum. The time history analysis was performed under irregular waves and currents. The time-domain simulations were transformed to the frequency domain by Fast Fourier Transform (FFT). The spectra were smoothed using Savitzky-Golay smoothing filters. The transfer functions of SFT horizontal and vertical displacements; and cable tensions were obtained for 30 realizations. Two major peaks have been observed in each transfer function (response spectrum). One of the peaks was associated with the peak wave frequency; the second peak was associated with the translational natural frequency of the SFT.

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“…1. Structural model of SFT used for numerical simulations [16,21] The JONSWAP spectrum Eq. (1) is calculated as shown in Fig.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…where ( )   f q,t is random wave loads generated based on the JONSWAP wave spectrum. Other parameters are those described in [16,17]. The mooring cables were modeled by the procedure described in [16,18,19].…”

Section: Equations Of Motionmentioning

confidence: 99%

Dynamic Characteristics of submerged floating tunnel under irregular waves

Muhammad

Mandokhail

Habib

et al. 2019

Journal of Applied and Emerging Sciences

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“…The wave theories are normally based on water depth, wave height, and wave period. The Airy wave theory, which holds for wave heights up to 10-15 m, covers a wide range and can consider significant waves of any actual sea states [22,23]. According to the Airy wave theory, the first-order velocity potential is given as follows [24]: cosh[ ( )] sin cosh( )…”

Section: Waves and Currents Modelingmentioning

confidence: 99%

“…However, simplified approaches, such as Morison's equation, can be used to evaluate the hydrodynamic forces on the SFT and give reliable estimates as compared to experimental data [26,27]. The hydrodynamic forces from ocean waves and currents, acting per unit length of the SFT are given by the modified Morison's equation as follows [4,23,24].…”

Section: Waves and Currents Modelingmentioning

confidence: 99%

Assessment of the Dynamic Behaviors of Submerged Floating Tunnel Under a High-Speed Train Loading

Muhammad

2019

OFOAJ

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Submerged floating tunnels (SFTs) are innovative structural solutions to waterway crossings and are more economical compared to the conventional structures such as cable-supported bridges, underground tunnels or immersed tunnels. The dynamic behaviors of SFT under real train loads is the primary design requirement of an SFT, However, it is not investigated using realistic train models. In this study, the China-star high-speed train is used to evaluate the dynamic displacements, internal forces and cable tensions of SFT. The tunnel is modeled by FEM, the cables are modeled by elastic catenary cables, and ocean waves and currents are modeled by Airy's wave theory. The SFT displacements, bending moments and cable tensions were significantly influenced by moving trains. The SFT experienced extreme vertical displacements and there was a large drop in the minimum cable tensions. The mooring cables were slacked both by magnitudes and speed of the moving trains, which should be avoided for the safety of SFT. This study recommends the additional buoyancies for the stability of SFT subjected to high speed trains.

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Experimental study on 3D hydroelastic response of entire long span submerged floating tunnel with catenary-mooring constraint and perpendicular regular waves action

Yang,

Wang,

et al. 2025

Tunnelling and Underground Space Technology

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The role of cable stiffness in the dynamic behaviours of submerged floating tunnel

Cited by 5 publications

References 6 publications

Dynamic Characteristics of submerged floating tunnel under irregular waves

Dynamic Characteristics of submerged floating tunnel under irregular waves

Assessment of the Dynamic Behaviors of Submerged Floating Tunnel Under a High-Speed Train Loading

Experimental study on 3D hydroelastic response of entire long span submerged floating tunnel with catenary-mooring constraint and perpendicular regular waves action

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