The study addressed the reliability of concrete as a valid construction material for Arctic structures. The focus will be on problems of structural deterioration caused by the loss of durability due to environmental effects, variation in material properties due to extreme temperature, and to abrasive damages or large concentrated stresses due to sea ice.
Assess the technology for compliant structures and create a basis for understanding and evaluating their behavior and reliability. The study addressed four major areas:
(1) define criteria for load estimation,
(2) investigate the dynamic response of compliant structures,
(3) investigate the behavior of individual structural components for developing inspection techniques, and
(4) develop procedures for estimating structural reliability.
The objective was to develop and evaluate the response of a stiff biaxial stress sensor in ice and permafrost under different loading conditions. Recommendations will be made on future designs and uses of the sensor in materials exhibiting time dependant mechanical properties. The sensor has a low thermal sensitivity and is not affected by differential thermal expansion between ice and gauge or ice creep. To provide a means for reliable, inexpensive ice stress measurements which are needed to understand ice related problems.
The objective was to develop guidelines for evaluating defects found during in-service inspection of offshore structures. The approach is based on fracture mechanics methods where the key ingredient in the assessment methodology is a semi- empirical model, relating crack growth rate to anticipated operating conditions. Various models developed for predicting growth rates of cracks under random loading will be studied by comparing analytical predictions with experimental results on growth of surface cracks in representative offshore steel weldments.
To study designs of tension-leg platforms (TLP); to understand how platform foundations interact with the soil to influence the stability and reliability of the platform; to identify research topics and to initiate work on topics identified as being critical.
This was a joint Industry Project (JIP) to study the response of clay soils to the deflection of a pile with large, lateral cyclic loading and erosion of stiff clay due to repeated lateral loading. Studies involve an evaluation of the continuum mechanics and the finite element methods, and the P-Y method, in solving the problem of determining soil response for offshore structures. In-situ data and undisturbed samples for laboratory testing will be obtained from sites where major pile experiments were conducted.
To develop an improved correlation between measured soil properties and maximum load transfer in single piles and to improve the understanding of load transfer mechanisms in single piles and pile groups in cohesionless soils. This is a companion study to Project No. 45. The purpose of this study is to consider the geotechnical problems associated with the foundation supports for tension-leg platforms.
To investigate the behavior of single piles and pile groups under dynamic loading. Tests were conducted on instrumented full scale single piles and pile groups. The project is a cooperative effort with Federal Highway Administration (FHWA), Furgro-Gulf, Inc., the University of Houston, and 9 other sponsors (Arco, Brown and Root, Chevron, Citgo, Exxon, Marathon, Mobil, Raymond International, and Shell). The purpose of the program is to improve the understanding of dynamic pile-soil-pile interaction of single piles and pile groups in a cohesive soil.
To determine the lateral forces generated by moving sea ice on artificial islands and offshore structures. This focuses on exploration and development operations in the Beaufort, Chukchi, and Bering Seas. The approach is to measure the effective ice stress at relatively long distances from such islands, to measure the ice displacement simultaneously and to determine the effective island width or structure width during ridge building events.
Conduct a comprehensive review of the research and development programs aimed at Arctic undersea structures inspection and the types of NDE equipment necessary for present and future undersea structures inspection.
