Earthquakes, seabeds and offshore structures

Motivation

Offshore wind is expanding rapidly into earthquake-prone seas, including East Asia. Most offshore wind turbines stand on large-diameter monopiles. Their seismic design often relies on simplified assumptions: seismic waves rising vertically through the soil, and the surrounding seawater either ignored or reduced to an added mass. Neither assumption is guaranteed to be safe.

What I study

• Fluid–soil–structure interaction (FSSI): coupled modelling of the seawater, the seabed soil and the monopile–tower system.
• Oblique seismic incidence: how the angle at which P and SV waves arrive changes the motion at the seabed and the forces in the foundation.
• Water-depth effects: how the water column changes the system response with depth.
• Site amplification: how soft marine sediments amplify shaking before it reaches the structure.
• Implications for seismic hazard assessment and design of monopile foundations.

Approach

Numerical modelling of the coupled seawater–seabed–monopile system in OpenSeesPy, with seismic wave input at different incidence angles and parametric studies across water depths and soil profiles to isolate the mechanisms that govern foundation demand.

Output

Lone, Li, Zhang, Rasheedy & Al-Shaebi (2026). Fluid–soil–structure interaction under oblique seismic incidence: Mechanisms governing offshore wind turbine foundation demand. Structures, 94, 113318. doi:10.1016/j.istruc.2026.113318

• Offshore wind turbines
• Monopile foundations
• Fluid–structure interaction
• Seismic wave propagation
• Water depth effects
• Site amplification
• OpenSeesPy

About OpenSees

OpenSees (Open System for Earthquake Engineering Simulation) is the open-source finite element framework widely used in earthquake engineering research. OpenSeesPy is its Python interface. I work with both as a developer and a user.

What I do

• Development: building and extending OpenSees / OpenSeesPy functionality needed for coupled soil–fluid–structure and wave-propagation problems.
• Modelling: nonlinear finite element models of soil–structure and fluid–soil–structure systems, including offshore wind turbine monopiles.
• Seismic analysis: nonlinear time-history analysis with seismic wave input at different incidence angles.
• Workflows: reproducible Python pipelines for model generation, batch and parametric runs, and post-processing.
• Performance: combining OpenSees workflows with CUDA-accelerated computation for large models.

• OpenSees
• OpenSeesPy
• Python
• Finite element method
• Nonlinear dynamics
• Soil–structure interaction

Coupled seawater–seabed–structure models are large, and parametric studies over incidence angles, water depths and soil profiles require many runs. I develop CUDA-accelerated computation to cut run times and make these studies practical.

• CUDA
• High-performance computing
• Wave propagation
• Parametric studies

My master's thesis at Bharath Institute of Higher Education and Research, Chennai, supervised by Dr. T. P. Meikandaan, studied the fracture mechanism of reinforced concrete beams strengthened with hybrid fibre-reinforced polymer (FRP) laminates. It examined how hybrid laminates change crack development and failure behaviour of strengthened beams.

• Reinforced concrete
• FRP strengthening
• Fracture mechanics