A method for applying hoop prestress to fan foundation ring connections

Abstract

The invention provides a method for applying circular prestress on a fan foundation connector. The method can be used for reinforcing out-of-operation foundation circular connection of a built project put into operation, and can also be used for avoiding stress defects of foundation circular connection in a newly-built project. Steel pilasters and base plates are fixed to the outer side of a concrete pier, prestress steel strands penetrate through anchor plates of the steel pilasters and limiting rings of the base plates, prestress is applied to the two ends of each prestress steel strand, and special anchoring heads are installed at the two ends of each prestress steel strand. At last, thickened areas are arranged on the upper surface and the side face of the concrete pier, and are evenly provided with circular steel bars and vertical steel bars so as to protect the prestress steel strands, the steel pilasters, the special anchoring heads and the base plates in a wrapping manner. The multiple limiting rings are evenly welded to the base plates to limit the prestress steel strands. Each steel pilaster is composed of a pilaster base plate, rib plates and anchor plates, wherein the rib plates are evenly welded to the pilaster base plate, the anchor plates are welded to the pilaster base plate and the rib plates, each rib plate has the wide inside and the narrow outside, and therefore the two ends of each prestress steel strand perpendicularly act on the corresponding anchor plate.

Description

technical field [0001] The invention belongs to the technical field of foundation structures of wind power generation towers, and in particular relates to a method for applying hoop prestress to the ring connections of wind turbine foundations. Background technique [0002] At present, the connection between the single-pipe wind power tower and the bottom reinforced concrete foundation ring is usually achieved by pre-embedding the foundation ring in the reinforced concrete foundation, and connecting the upper tower and the foundation ring through flanges. However, due to the shallow embedding depth of the foundation ring and the non-prestressed structure, the use of the foundation ring to connect the upper tower and the bottom foundation has the following defects: the foundation ring area has both steel bars and foundation ring reinforcement, and the following areas only have steel bars, so The sudden change in strength and stiffness causes the cracks caused by concrete hard...

AI Technical Summary

Problems solved by technology

However, due to the shallow embedding depth of the foundation ring and the non-prestressed structure, the use of the foundation ring to connect the upper tower and the bottom foundation has the following defects: the foundation ring area has both steel bars and foundation ring reinforcement, and the following areas only have steel bars, so The sudden change in strength and stiffness causes the cracks caused by concrete hardening shrinkage and stress to concentrate between the foundation ring and the bottom plate, and the crack width increases; the foundation ring splits the inner and outer concrete. Due to the different properties of steel and concrete, the thermal expansion coefficient is different and the deformation Uncoordinated, temperature action, load action, frost heave, etc. make the gap between the foundation ring and concrete continuously increase, deteriorating the anchoring effect of the two; under the reciprocating fatigue load of the fan, the concrete cracks and gaps in the connection area of ​​the foundation ring continue to increase and develop, and then Make the foundation ring vibrate and shake in the foundation concrete to produce an impact on the concrete

[0003] The force defects in the connection of the foundation ring lead to the gradual outbreak of such problems in the projects that have been put into operation, seriously affecting the operation quality and safety of the wind turbine

However, the newly built projects that still use the basic ring connection still have no good measures to avoid this defect

Images