Rotatable Comb Bridge Expansion Joint for Transverse Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional bridge expansion joints, including comb-type and modulus-type joints, fail to effectively manage large transverse shifts and rotations of girders under wind and other forces, leading to damage and breakage of comb teeth and separation of girders.
Innovation Solution
A modularized comb-type bridge expansion joint design featuring rotatable joints with columnar rotating shafts, resilient damp materials, and spherical-shaped bolts, allowing for flexible rotation and transverse shifting of comb teeth, along with a safe spring connection to accommodate vertical shifts, ensuring the joint remains intact and reduces wear and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If comb teeth are rigidly connected to resist vertical loads, then load-bearing capacity is improved, but transverse shift and rotation cause comb teeth breakage
Solution Approach 1:
The comb plate is divided into multiple independent comb teeth that can rotate relative to each other around a transverse axis. Each comb tooth is connected to the comb plate body through a rotation joint, allowing individual teeth to adapt to transverse shifts and rotations independently while maintaining load-bearing capacity through their rigid connection to the bridge girder.
Solution Approach 2:
The connection between comb teeth and the comb plate body is designed as a rotatable joint rather than a rigid fixed connection. This dynamic joint allows the comb teeth to rotate and adapt to transverse movements and rotations of the bridge girder, preventing breakage while maintaining structural integrity under vertical loads.
2Adaptability or versatility
If comb-type joint is used to allow expansion movement, then expansion capability is improved, but transverse shift causes comb teeth to break easily
Solution Approach 1:
The comb plate is segmented into multiple independent comb teeth that can rotate relative to each other. This segmentation allows each tooth to independently accommodate transverse shifts and rotations while the overall comb structure maintains its expansion capability through the interdigitating teeth design.
Solution Approach 2:
The rotatable joint between comb teeth and the comb plate body introduces dynamic adaptability, allowing the comb teeth to rotate and follow the transverse movement of the bridge girder. This dynamic response prevents the rigid breakage that would occur in traditional comb-type joints under transverse loading.
3Adaptability or versatility
If modulus-type joint is used, then transverse shift is accommodated, but girders separate and supporting seat breaks
Solution Approach 1:
The expansion joint is divided into multiple modules, each comprising a comb plate with multiple comb teeth. This modular segmentation allows each module to independently accommodate transverse shifts through rotation, while the overall structure maintains girder connection integrity through the continuous interdigitating comb teeth across modules.
Solution Approach 2:
The comb teeth from adjacent comb plates are interdigitated and work together as a unified structure. This merging of multiple comb teeth into a cooperative system allows the joint to accommodate transverse shifts through rotation while maintaining the stability and integrity of the girder connection.
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 design effectively mitigates damage and wear by allowing flexible movement under external forces, extending the joint's lifespan and simplifying maintenance, while maintaining structural integrity during multi-directional shifts, and reducing manufacturing and maintenance costs.
Implementation Method 1
holes for said fixing bolts on said seat being kidney-shaped, and being filled with resilient damp material around said fixing bolts
Implementation Method 2
a safe spring connection to accommodate vertical shifts
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A large module type comb-shaped bridge expansion joint device for resisting a super dislocation, comprises at least two modules located parallel in the direction of a bridge's width, and each module includes a fixed comb plate (2) and a movable comb plate (1), which are respectively disposed on girders located at the two sides of the bridge expansion joint, said movable comb plate (1) crosses over the bridge expansion joint, both of said fixed comb plate (2) and said movable comb plate (1) have a plurality of comb teeth (22), (11) at their opposite ends, and the comb teeth (11) of said movable comb plate (1) interdigitate with the comb teeth (22) of said fixed comb plate (2),characterized in that the root of said movable comb plate (1) rotatably joints with a seat (5) fixed on the girders, and the comb teeth (22) of said fixed comb plate (2) rotatably joints with the root of said fixed comb plate (2), while, the middle of the comb teeth (22) of said fixed comb plate (2) is movably set on an underlay (6) fixed on the girders and can be shifted transversely relative to the underlay (6). In this invention, when the girders have transverse shift under the effect of the wind or other external forces, the movable comb plate and its comb teeth will rotate correspondingly and the comb teeth of the fixed comb plate will also rotate correspondingly, then the breaking of the comb teeth will be avoided.