Partially prefabricated modular foundation system

Abstract

A wind turbine foundation having a central pedestal, a bottom support slab, and a plurality of prefabricated radial reinforcing ribs. The pedestal and support slab are poured in situ at the site. When the concrete cures the support slab is united to the prefabricated ribs and the ribs are also united to the pedestal. The result is a continuous monolithic foundation wherein loads are carried across the structure vertically and laterally through the continuous structure by doweled and spliced reinforcing steel bars which are integrally cast into the pedestal, ribs and support slab. The slab thus behaves structurally as a continuous slab reducing deflections, improving fatigue conditions and increasing the stiffness of the foundation as well as allowing for the benefits of an economical design.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to a method for building partially prefabricated foundations for supporting wind turbines towers.[0003]2. Description of the Related Art[0004]Conventional gravity style foundations for large wind turbine usually comprise a large, thick, horizontal, heavily reinforced cast in situ concrete base; and a vertical cast in situ cylindrical pedestal that is installed over the base. There are several problems that are typically encountered during the construction of such foundations.[0005]The main problem is the monumental task of managing large continuous concrete pours, which require sophisticated planning and coordination in order to pour more than four hundred yards of concrete in one continuous pour, without having any cold joints in.[0006]Another problem is logistics coordinating with multiple local batch plants the delivery plan of the large number of concrete trucks to the job site in a timely, or...

AI Technical Summary

Benefits of technology

[0040]Another object of this invention is to provide the wind energy industry with reliable and readily available designs, and prefabricated components, for every wind energy project wherein foundation designs are pre-approved by and coordinated with turbine manufacture.

[0041]A further object of this invention is to use standard designs to reduce engineering work and simplify the permitting process, as well as improve project construction schedule.

[0042]Still another object of this invention is to utilize standard pre-approved designs resulting in significant reduction in engineering fees and third party approval fees.

[0043]It is also the object of this invention is to provide wind turbine vendors with the ability to select pre-approved complete foundation designs for wind turbine foundation based on project and site variables including turbine model and tower height; site geotechnical characteristics; and desired foundation style such as gravity or piling.

[0044]Another object of this invention is to provide foundation contractors with the convenience and economy of using commercially available prefabricated components with complete assembly and detail drawings that can be delivered to any project site with short lead time.

[0045]A further object of this invention is to improve the quality and productivity of foundation construction due to experience gained from practicing standard construction techniques.

Problems solved by technology

When concrete is cast in massive sections for wind tower foundations, temperature can reach 160 degree F. and the risk of thermal cracking becomes very high unless cooling techniques are applied.

Thermal cracking often compromises the structural integrity of the foundations.

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