Concave Arch Bridge with Intermediate Deck for Reduced Mass

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Solution Overview

Problem

Traditional arch bridges face limitations in spanning large areas while maintaining structural integrity and aesthetic appeal, often requiring additional supports and materials, and can be stressed by thermal expansion and contraction.

Innovation Solution

The design features a bridge with two concave downwards arches connected by a lowered intermediate deck, which distributes vertical forces horizontally to the arches, reducing outward thrust and allowing for a wave-shaped bridge deck with elevated sections, thus minimizing material usage and structural stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If traditional arch bridges use higher arches to span large areas, then the span length increases, but the height and mass of the structure increase

Engineering Contradiction:
Improvespan lengthVSAvoidheight and mass
Core Design Contradiction:
Length of stationary objectVSWeight of stationary object

Solution Approach 1:

The bridge deck is segmented into two distinct levels: an upper deck supported by the arches at elevated points, and a lower intermediate deck that spans between the arches at reduced height. This segmentation allows the bridge to achieve long span lengths through the arches while maintaining reduced overall height and mass through the intermediate deck configuration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a vertical dimensionality change by positioning the intermediate deck at a lower elevation between the arches, creating a multi-level structure. This dimensional arrangement allows the bridge to span large horizontal areas through the arches while reducing the vertical profile and mass requirements compared to a single elevated deck

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If traditional arch bridges use additional secondary supports to maintain structural integrity, then structural stability improves, but device complexity and material usage increase

Engineering Contradiction:
Improvestructural integrityVSAvoidnumber of supports and materials
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The intermediate deck serves multiple functions simultaneously: it acts as a structural support element, a load-bearing component, and part of the bridge deck itself. By merging these functions into a single integrated element, the invention eliminates the need for separate secondary supports while maintaining structural integrity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The intermediate deck is designed as a multi-functional element that provides structural support, carries traffic loads, and forms part of the bridge deck configuration. This universal application of the intermediate deck reduces the number of specialized components needed, thereby simplifying the overall structure and reducing material usage

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Weight of stationary object

If arches are lowered to reduce height and mass, then the rise decreases and material usage reduces, but outward thrust increases

Engineering Contradiction:
Improveheight and massVSAvoidoutward thrust
Core Design Contradiction:
Weight of stationary objectVSForce

Solution Approach 1:

The intermediate deck acts as a mediator that connects the two arches and helps distribute and balance the outward thrust forces. By positioning the intermediate deck between the arches at a lower level, it provides structural counterbalance that reduces the net outward thrust on the abutments while allowing the arches to maintain a lower rise

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enables longer span lengths with reduced height and mass, eliminating the need for traditional secondary supports, while maintaining structural integrity and allowing for a simpler, aesthetically pleasing construction using less material.

Implementation Method 1

the intermediate deck together with the first and second arch provides a bridge deck with elevated sections at the top points... distributes vertical forces horizontally to the arches, reducing outward thrust

Methodology Applied
Scientific EffectForce distribution: Force

Data Source

PatentEP4118266B1An arch bridge
Publication Date: 2024.07.17 SCHJELDERUP TRONDAHL ARKITEKTER AS
  • EP4118266B1 patent drawingFigure 1A~1C
  • EP4118266B1 patent drawingFigure 2A~2B
  • EP4118266B1 patent drawingFigure 3A~3C

AI summary

An arch bridge comprising a bridge deck for providing a walking/driving surface. The bridge deck is supported by a first arch and a second arch both concave downward, and each comprising a top point which if defined by a highest point of the arch viewed in a vertical plane. An intermediate deck is arranged between the first and second arch and connected at a location below the top point of respective arches such that the intermediate deck is lowered between the top points. The bridge deck is provided by the intermediate deck and a section of the arches located above the location and including the top point, so that the bridge deck of the arch bridge is elevated at the top points.