ES2343055B1 - PROCEDURE FOR THE REPAIR OF FOUNDATIONS OF AEROGENERATORS. - Google Patents

Abstract

Foundation repair procedure for wind turbines

Constituted by a first stage in which Performs a damage analysis. A second stage where drill holes until the lower steel flange of the fuste and interested in the radial cracks of the foundation. A third stage in which shutters are placed in the mouth of the perforations and proceed to the injection of high resin or medium viscosity and a fourth stage in which a strip of steel tensioned by a jack and fixed by high threaded bars resistance.

Description

Foundation repair procedure for wind turbines

The present invention relates to a system of pathology analysis and foundation repair wind turbines, with which a more effective result is achieved and durable than is currently known, prolonged life of the wind turbine.

The global growth in the number and size of wind turbines have caused them to be built and installed increasingly high and heavy turbines that require significant reinforced concrete foundation bases. Growth is being so fast that it has not been possible to ratify with real experiments the validity of the design assumptions of these foundations, before Keep building more. The consequence is that right now Begins to check that the movements of the shafts of the turbines, as a result of wind pressure, are in many cases, far superior to the admissible ones, causing damage in the concrete of the foundations.

The present invention proposes a procedure effectively and specifically dedicated to the function in question, which of place to a foundation repair system of wind turbines of simple execution, with low cost and results technically appreciable. The characteristics of this system they offer the state of the art a novel, simple embodiment, simple and highly economical execution compared to others traditional alternatives such as the replacement of affected foundations or the trimming with perimeter beams of reinforced concrete.

It has its field of application within the construction industry and uniquely within the framework of the auxiliary industry of maintenance of large structures, more specifically in the repair and rehabilitation of structures of mass or reinforced concrete.

It is not known in this industry sector no procedure or device with direct application for solve in a specific way the problem that solves the present invention Thus the lack of a system that contributes to state of the art the novel solutions proposed, presents before this invention the following drawbacks:

Known models are based on the execution of heavily armed circular beams acting as foundation strips, also circular and concrete armed affected, prone to deterioration by vibration and swing of the shaft, cracking of reinforced concrete is coming trying to pour or inject very fluid resins at low pressure, which get, at best, a mere sealed superficial. This procedure fails to solve the problem, since it is not very durable and does not monolithize the inside of the base of the wind turbine The cost of this usual procedure is very high. The use of concrete in the repair of the beam zunchado forces to keep the wind turbine stopped for many days, which represents a loss of profits on the farm, unattainable by the turbine operating company.

Faced with the described drawbacks, the The present invention provides solutions to the state of the art novel, simple, fast and easy to execute, which give as result the following advantages:

The cracking of reinforced concrete is treated by means that inject into all the fissures, interiors and outer, synthetic, inert and elastic materials, which do not they have aging so the longevity of the base is prolongs significantly more than with procedures usual. This procedure manages to solve the problem, since which is very durable and monolithizes the inside of the base of the wind turbine The cost of this procedure is less than usual procedures given its simplicity, speed and durability. Its execution is very fast, so the downtime of the exploitation is minimal, thus making exploitation more profitable. The foundations repaired by the proposed procedure reduces up to 98% the movement of the shafts of their sites originals

All these conjugated elements give rise to a final result in which differentiating characteristics are provided significant compared to the state of the art.

Thus, the procedure proposed herein invention is constituted from the four stages following:

First stage: Mathematical analysis of calculation based on the principles of flat elasticity, which represents the Tensioning behavior of the foundation when subjected to loads and project actions depending on the movements suffered at the base of the wind turbine caused by the stresses supported by the shaft, the state of the concrete is also analyzed, the fissures produced and their location, leading to a damage assessment.

Second stage: Perforations are made in the concrete until the bottom steel flange of the shaft is reached embedded in the concrete. Other perforations are also performed that interested in the radial cracks of the foundation.

Third stage: Outside the perforations are placed shutters consisting of tubes of steel that press into the perforation, inside which are coupled rubber sleeves, which through a set of nuts and washers cause, by tightening the nuts, a radial expansion that close the holes hermetically, finishing their placement using a ball wrench, where you proceed to inject high or medium viscosity resins at pressures up to 600 K / cm2, This injection is intended to refill all gaps, cracks and fissures that have occurred, as well as regenerate fractured concrete During this injection process it control possible movements of the shaft and ferrule of the wind turbine

Fourth stage: Once the concrete is consolidated, perform structural calculations to determine the value of the necessary testing force depending on the movements detected in the wind turbine, foundation geometry on the pedestal, ferrule and shoe and the loads transmitted by the wind turbine to your foundation. Known the value of the necessary pressures to transmit between the active strap and the pedestal, a belt is dimensioned that surrounds the entire base in order to constrict the concrete massif to prevent it from opening, as a result of the tractions that produces the movement of the wind turbine shaft, of measurements suitable, manufactured with steel plate or fiber laminate carbon, which has attached at one end, a first plate that fixed to the concrete, using epoxy adhesive and mechanical anchoring and the another end of the belt also attaches a second plate, without fixing to concrete, which allows the displacement and testing of the material. Both plates are made of steel and have a hook for a hydraulic jack, which pulls the free end of the belt up to Give him the tension recommended by the calculations. The cat pulls the second plate with the force obtained from the calculations, until it is carried to your right place At that time, between both plates are placed high strength threaded bars, being able to proceed to remove the cat Finally we proceed to the mechanical anchoring of this end to the concrete, by means of plugs and screws. This way you achieves a foundation test that compensates for the tractions that they give rise to failures and damages.

The product achieved by the procedure proposed is a base that holds the shaft of a wind turbine that after suffering deterioration due to oscillations of the wind turbine shaft are repaired and reinforced through perforations in the concrete until the flange of bottom steel of the shaft embedded in the concrete and that also interested in the radial cracks of the foundation. Injecting resin of high or medium viscosity with pressures up to 600 Kg / cm2, covering the mouths of the perforations with shutters provided with ball keys. Once the concrete is consolidated and after perform structural calculations to determine the value of the necessary testing force depending on the movements detected in the wind turbine, foundation geometry on the pedestal, ferrule and shoe and the loads transmitted by the wind turbine to your foundation is sized a strip that surrounds the entire base with the object to constrict the concrete mass to prevent it from opening, of suitable measures, manufactured with steel plate or laminate carbon fiber, thus getting a foundation test which compensates for tractions that lead to failures and damage.

For a better understanding of this memory descriptive are accompanied by drawings that by way of example not limiting, describe a preferred embodiment of the invention:

Figure 1.- Concrete base and shaft

Figure 2.-Detail of perforations and fissures

Figure 3.- External belt

Figure 4.- Tension plates

In these figures the following stand out numbered items;

one.-

Wind turbine base

2.-

Shank

3.-

Perforations to the steel flange

4.-

Steel flange inside the shaft

5.-

Perforations to the fissures

6.-

Cracks

7.-

Shutters

8.-

Belt

9.-

First sash plate

10.-

Second sash plate

eleven.-

Hydraulic jack hitch

12.-

Threaded rods

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A preferred embodiment of the invention proposal, is constituted from the following stages: In a First stage, a mathematical calculation based on the principles of flat elasticity, which represents the Tensioning behavior of the foundation when subjected to loads and project actions depending on the movements suffered at the base (1) of the wind turbine caused by tensions supported by the shaft (2), the state of the concrete, the cracks produced (6) and their location, which It leads to an assessment of the damage. In a second stage, once the damage has been verified, perforations are carried out (3) in the concrete until reaching the bottom steel flange (4) of the shaft (2) embedded in the concrete. Other perforations are also performed (5) interested in radial cracks (6) of the foundation. In a third stage are placed outside the perforations (3 and 5) shutters (7) consisting of steel tubes are placed that they press into the perforation, inside which they are coupled rubber sleeves, which through a set of nuts and washers originate, by tightening the nuts, a radial expansion that they close the holes hermetically, finishing their placement using a ball wrench, where you proceed to inject resins of high or medium viscosity at pressures up to 600 K / cm2, This Injection aims to fill all the gaps, cracks and cracks that have occurred, as well as regenerating concrete fractured. During this injection process the possible movements of the shaft (2) and the wind turbine ferrule. Once the concrete is consolidated, in a fourth stage, they are made some structural calculations to determine the value of the force of necessary testing depending on the movements detected in the wind turbine, foundation geometry on the pedestal, ferrule and shoe and the loads transmitted by the wind turbine to its foundation. Known the value of the necessary pressures to transmit between the active strip (4) and the pedestal is dimensioned by a belt (8) that surrounds the entire base (1) in order to constrict the concrete massif to prevent it from opening, as a result of the tractions that produces the movement of the shaft (2) of the wind turbine, measuring suitable, made of steel plate, which is coupled in a end, a first plate (9) that is fixed to the concrete, by epoxy adhesive and mechanical anchor and the other end of the belt (8) also attaches a second plate (10), not fixed to the concrete, which It allows the displacement and testing of the material. Both plates (9 and 10) they are made of steel and have a hook for a cat hydraulic (11), which pulls the free end of the belt (8) until Give him the tension recommended by the calculations. The cat pulls the second plate (10) with the force obtained from the calculations, up to Take it to its right place. At that time, between the two plates place high strength threaded bars (12), being able to proceed to remove the cat. Finally proceed to the anchored mechanical from this end to concrete, by means of plugs and screws. From This way a foundation test is achieved that compensates for the tractions that give rise to failures and damages.

Claims (5)

1. Wind turbine foundation repair procedure constituted from the first stage of a mathematical calculation based on the principles of flat elasticity, which represents the tensional behavior of the foundation when subjected to loads and project actions depending on the movements suffered at the base of the wind turbine caused by the stresses supported by the shaft, likewise the state of the concrete, the cracks produced and their location are analyzed, which leads to an assessment of the damage which will determine the quantity, direction and length of the perforations carried out in a second stage, characterized in that in the second stage perforations are made in the concrete until reaching the lower steel flange of the shaft embedded in the concrete. Other perforations that interest the radial cracks of the foundation are also made. 2. Wind turbine foundation repair procedure according to claim 1, characterized in that in a third stage outside the perforations are placed shutters consisting of steel tubes that press into the perforation, in which interior sleeves are coupled rubber, which by means of a set of nuts and washers originate, when tightening the nuts, a radial expansion that closes the holes hermetically, finishing its placement by means of a ball wrench, whereby high or medium viscosity resins are injected into pressures of up to 600 K / cm2, filling the gaps, cracks and cracks that have been produced, as well as regenerating the fractured concrete. 3. Wind turbine foundation repair procedure according to claims 1 and 2, characterized in that during the injection process the possible movements of the shaft and the ferrule ferrule are controlled. 4. Wind turbine foundation repair procedure according to claims 1 to 3, characterized in that once the value of the necessary pressures to be transmitted between the active strip and the pedestal is known, a strip is dimensioned that surrounds the entire base in order to constrict the solid concrete to prevent it from opening, as a result of the tractions produced by the movement of the wind turbine shaft, of suitable measures, made of steel plate or carbon fiber laminate, which has a first plate attached at one end it is fixed to the concrete, by means of epoxy adhesive and mechanical anchoring and the other end of the belt also attaches a second plate, without fixing to the concrete, which allows the displacement and testing of the material, both plates are made of steel and have a hook for a hydraulic jack, which pulls the free end of the girdle until it is given the tension recommended by the calculations, the cat pulls the second p lacquer with the force obtained from the calculations, until it is taken to its correct place, at that time, between both plates, high-strength threaded bars are placed, and the cat can be removed, finally the mechanical anchoring of this end is carried out to the concrete , using dowels and screws. In this way a foundation test is achieved that compensates for the tractions that lead to failures and damage. 5. Wind turbine foundation rehabilitation characterized in that it is constituted by the product obtained from the previously described stages.