دانلود رایگان مقاله انگلیسی روش طراحی و بهینه سازی مناسب برای پایه شمعی جهت تقویت توربین بادی - الزویر 2018

Abstract

A geotechnical design and optimization procedure for piled-raft foundations to support tall wind turbines in clayey and sandy soil are presented in this paper. From the conventional geotechnical design, it was found that the differential settlement controlled the final design and was considered as the response of concern in the optimization procedure. A parametric study was subsequently conducted to examine the effect of the soil shear strength parameters and wind speed (random variables) on the design parameters (number and length of piles and radius of raft). Finally, a robust design optimization procedure was conducted using a Genetic Algorithm coupled with a Monte Carlo simulation considering the total cost of the foundation and the standard deviation of differential settlement as the objectives. This procedure resulted in a set of acceptable designs forming a Pareto front which can be readily used to select the best design for given performance requirements and cost limitations.

5. Conclusion

A geotechnical design optimization procedure for a piled-raft foundation to support a tall wind turbine on clayey and sandy soil is presented in this paper. The procedure can be easily extended to the geotechnical design of piled-raft foundations to support other structures. The geotechnical design conducted in this study followed the analytical equations available in the literature and indicated that the final design is controlled by the differential settlement and the rotation of the foundation rather than the bearing capacity or the total settlement. The parametric study showed that for both types of soil, the design requirements can be met by increasing the number of piles, increasing the length of the piles, or increasing the radius of the raft when the wind speed is increased. For a higher undrained cohesion (in clayey soil) and a higher friction angle (in sandy soil), a smaller foundation was enough to meet the design requirements. The robust optimization procedure resulted in easy-to-use graphs, called Pareto fronts, which show a clear trade-off relationship between the cost and the standard deviation of the responses (differential settlement) for both soils. Although these graphs can be utilized to select the suitable design for a given set of performance requirements (variation in differential settlement) and cost limitations, the most suitable design solution is determined using the knee point concept.