OFFSHORE TESTING
It has been estimated the world's energy consumption will increase by 56% over the next 30 years. Nuclear power and renewables are the fastest-growing sources of world energy, both increasing at an average annual rate of 2.5%.
Worldwide, hydroelectricity and wind are the two largest contributors to the increase in global renewable electricity generation (IEA, 2013). Hydrocarbons do however continue to play a major role in the energy market, with platforms being constructed in deeper water to enable access to new oil and gas fields. Offshore energy structures, including wind turbines and oil and gas platforms, experience complex interactions between structure, wind, wave and soil, due to a variety of static, cyclic and dynamic loadings. The design of the foundation for such structures is therefore key for their long-term performance, reduction in foundation cost, and the impact on the environment.
We have developed a range of apparatuses that can replicate the two and three dimensional static and dynamic cyclic loadings applied to the foundation soils of offshore energy structures. These include triaxial and direct simple shear systems, which enable the cyclic strength of offshore soils to be determined, along with consolidation properties, small-strain stiffness measurements using local transducers, and static undrained strengths to be assessed for use in the design process.
Test Standards for Offshore Testing
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ASTM D-3999:
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Determination of Young’s modulus and hysteretic damping coefficient of a soil via the triaxial apparatus. These parameters are important when conducting dynamic response analyses of offshore soils during seismic events, or when assessing the natural frequency of structure and foundation. |
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ASTM D-5311:
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Determination of the undrained cyclic strength of a soil via the triaxial apparatus. This parameter is used to evaluate the ability of an offshore soil to resist the repeated cyclic shear stresses induced by wave and wind loading over time. |
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ASTM D-6528:
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Determination of the static shear strength parameters of a soil via the direct simple shear apparatus. This standard may also be used as a guide for performing cyclic simple shear tests on offshore soils to determine the cyclic strength for use in design. |
