Mechanical characteristics of pile cap foundations for offshore wind farms

Abstract

In order to investigate the force transmission mechanism of offshore high pile cap foundation under large bending moment loads from wind turbine units and complex marine environmental loads, we use a step-by-step loading method in a numerical model to stimulate the mechanical characteristics of the foundation under different load magnitudes. We obtain the key bearing parts of the high pile cap structure, and analyze the mechanical characteristics of the concrete cap and oblique steel pipe pile. The results show that as the wind turbine loads and environmental loads increase, the bearing mode of the concrete cap shifts from axial compression to bias compression. The contact area between the top of the steel pipe pile and the concrete cap is identified as the critical part for load bearing and transmission, where tensile damage of the concrete first occurs. With increasing loads, the maximum stress of the steel pipe pile shifts from the wave flow load application point to the mud surface. This research clarifies the load transfer law and key parts of the high pile cap foundation, providing guidance for the safety design of foundation structures.

Keywords

• structural engineering
• high pile cap foundation
• steel pipe pile
• large bending moment load force
• transmission mechanism
• step-by-step loading
• the key bearing parts
• the load transfer