Plastic Height Adjustment Units for Wind Tower Foundation Protection

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Solution Overview

Problem

Conventional height adjustment screws made of stainless steel in tower erection methods lead to excessive surface pressure on foundations due to their higher rigidity, potentially causing damage, and increasing costs by requiring multiple screws for load distribution, while steel screws fail under the weight of the tower, concentrating load flow and causing damage.

Innovation Solution

Using plastic height adjustment units designed as screws with a metric thread, which can yield under excessive load, allowing the grout joint to distribute the load evenly and preventing foundation damage, thus reducing costs and ensuring safe load transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If stainless steel height adjustment screws are used to level the load distribution ring, then the leveling precision and load-bearing capacity are improved, but the surface pressure on the foundation becomes excessive and foundation damage may occur

Engineering Contradiction:
Improveload-bearing capacityVSAvoidexcessive surface pressure on foundation
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter of the height adjustment units from stainless steel to plastic, which has lower rigidity and strength. This parameter change allows the plastic units to deform under excessive load, preventing the concentration of stress on the foundation while still providing sufficient leveling function during construction.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The plastic height adjustment units serve as a cushioning element that can deform under excessive load before the foundation is subjected to damaging stress. The plastic material absorbs excess energy through deformation, protecting the foundation from direct stress concentration while maintaining the leveling function.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If multiple stainless steel height adjustment screws are used to distribute the load, then the reliability of load transfer is improved, but the manufacturing cost increases

Engineering Contradiction:
Improveload transfer reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive plastic height adjustment units that can be easily manufactured and replaced. These plastic units are designed to be disposable or replaceable, eliminating the need for expensive stainless steel screws while maintaining sufficient reliability for the construction phase. The lower cost material allows for more units to be used, distributing the load more effectively.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If stainless steel height adjustment screws are used, then the precision of height adjustment is improved, but the screws fail under the weight of the tower, concentrating load flow and causing damage

Engineering Contradiction:
Improveheight adjustment precisionVSAvoidfailure under tower weight
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the material properties from high-strength stainless steel to lower-strength plastic, which provides sufficient precision for height adjustment during installation but allows the units to fail safely under the full weight of the tower. This failure is controlled and prevents dangerous stress concentration on the foundation, as the plastic units deform or break in a predictable manner that distributes the load.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The plastic height adjustment units effectively distribute the load of the tower segments, preventing excessive surface pressure on the foundation and reducing material costs by allowing the grout to absorb the load, thereby ensuring a safer and more cost-effective tower erection process.

Implementation Method 1

The height adjustment units are dimensioned in such a way that they (together) can reliably absorb the weight or the load of the load distribution ring, but give way if such a large force acts on one of the majority of the height adjustment units that a surface pressure exceeding a limit value occurs through the height adjustment units the foundation acts

Methodology Applied
Scientific EffectYielding: Plasticity

Implementation Method 2

allowing the grout joint to distribute the load evenly and preventing foundation damage, thus reducing costs and ensuring safe load transfer

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP2427654B9Method for erecting a tower, and tower
Publication Date: 2017.06.21 WOBBEN PROPERTIES GMBH
  • EP2427654B9 patent drawingFigure 1
  • EP2427654B9 patent drawingFigure 2
  • EP2427654B9 patent drawingFigure 3A~3B

AI summary

The invention relates to a method for erecting a tower, particularly a tower of a wind power plant. A foundation (100) is thereby provided, a plurality of height adjustment units (500) is placed on the foundation, a load distribution ring (200) is placed on the plurality of height adjustment units (500), the load distribution ring (200) is leveled by adjusting the height adjustment units (500), and a crevice between the foundation (100) and the load distribution ring (200) is filled with a casting compound (300). A tower (400) is erected on the load distribution ring (200). The height adjustment units (500) are dimensioned such that the units are able to bear a first load in form of the weight of the load distribution ring (200); however, said units will yield if a great force impacts one of the plurality of height adjustment units such that a surface pressure exceeding a threshold value impacts the foundation by way of the height adjustment units. The height adjustment units are essentially made of plastic.