Effects of soil–structure interaction on real time dynamic response of offshore wind turbines on monopiles

Dynamic stiffness of monopile supporting offshore wind turbine generators

During earthquake ground shaking earth pressures on retaining structures can cyclically increase and decrease as a result of inertial forces applied to the walls and kinematic interactions between the stiff wall elements and surrounding soil. The application, based on limit equilibrium analysis, of a pseudostatic inertial force to a soil wedge behind the wall [the mechanism behind the widely-used Mononobe–Okabe (M–O) method] is a poor analogy for either inertial or kinematic wall–soil interaction. This paper demonstrates that the kinematic component of interaction varies strongly with the ratio of wavelength to wall height (λ/H), asymptotically approaching zero for large λ/H, and oscillating between the peak value and zero for λ/H<2.3. Base compliance, represented in the form of translational and rotational stiffness, reduces seismic earth pressure by permitting the walls to conform more closely to the free-field soil displacement profile. This framework can explain both relatively low seismic pre...

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Kinematic framework for evaluating seismic earth pressures on retaining walls

Many existing pile-supported marginal wharves within ports along the West Coast of the United States were designed in the late 1960s and early 1970s using the seismic design criteria available then...

Varun

Papers

A simplified model for lateral response of large diameter caisson foundations—Linear elastic formulation

Soil-pile-structure interaction simulations in liquefiable soils via dynamic macroelements: Formulation and validation

A generalized hysteresis model for biaxial response of pile foundations in sands