Elastic Duct Coupler Assembly for Precast Bridge Joint Sealing
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Solution Overview
Problem
Existing bridge construction methods using precast segments face issues with shear key damage, water leakage, and construction errors due to misaligned steel ducts, leading to structural integrity and durability problems.
Innovation Solution
The use of a socket type elastic duct coupler made of an elastic material, such as rubber, to connect precast segments, accommodating construction errors and improving watertightness while allowing flexible insertion of reinforcement members like steel strands and bars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a steel duct is used to connect precast segments, then shear resistance is improved through mechanical engagement, but construction errors and misalignment cannot be accommodated
Solution Approach 1:
The patent changes the physical state of the duct material from rigid (steel) to elastic (rubber or resin). This parameter change allows the duct to deform and accommodate construction errors while maintaining shear resistance through its elastic properties and mechanical engagement features.
Solution Approach 2:
The patent uses composite construction by embedding the elastic duct within concrete segments. The combination of elastic duct material and concrete creates a composite structure that provides both flexibility for error accommodation and structural strength for shear resistance.
2Stability of the object's composition
If steel ducts are rigidly connected, then structural stability is improved, but water leakage occurs at connection points
Solution Approach 1:
The patent changes the duct material parameter from rigid to elastic, which allows the duct to conform to connection surfaces and seal gaps. This elastic deformation capability prevents water leakage while the embedded concrete provides structural stability.
Solution Approach 2:
The elastic duct acts as a flexible sealing element that can deform to fill gaps and prevent water infiltration. The flexible nature of the elastic material allows it to create a watertight seal at connection points while maintaining structural integrity.
3Productivity
If precast segments are assembled quickly, then construction period is shortened, but shear keys are easily damaged during manufacturing
Solution Approach 1:
The patent extracts the shear connection function from traditional rigid shear keys and transfers it to the elastic duct system. The elastic duct with its engagement features provides shear resistance without the fragility of protruding shear keys, allowing faster construction with improved reliability.
Solution Approach 2:
The elastic duct serves as an intermediary element that provides shear connection between segments. Instead of relying on vulnerable protruding shear keys, the duct acts as a mediator that transmits shear forces through its elastic deformation and embedded engagement features.
4Ease of manufacture
If discontinuous surfaces are present between segments, then assembly is simplified, but water leakage and tendon corrosion occur
Solution Approach 1:
The elastic duct creates a flexible sealing barrier that bridges discontinuous surfaces between segments. The elastic material can deform to fill gaps and create a continuous waterproof path, preventing water leakage and tendon corrosion while maintaining simple assembly procedures.
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
Enhances structural stability and watertightness at connection points, reducing construction errors and facilitating efficient assembly of bridge lower structures with improved shear resistance and reduced leakage risks.
Implementation Method 1
a socket type elastic duct coupler, which is a duct coupler formed as a socket type and made of an elastic material
Data Source
AI summary
The present disclosure provides an assembly type bridge lower structure having a socket type elastic duct coupler and a method of constructing the same in which, in construction of an assembly type bridge lower structure that consists of an assembly type foundation part, an assembly type pillar part, and an assembly type coping part, a socket type elastic duct coupler is utilized, thus enabling shear key joining at connection portions of the assembly type foundation part, the assembly type pillar part, and the assembly type coping part, easily accommodating of construction error displacements of the socket type elastic duct coupler, improving watertightness at connection portions of the precast segments, easily accommodating an insertion angle of the insertion member including a steel strand, a steel bar, a reinforcing bar, a FRP, or the like, and preventing an overflow phenomenon that occurs when epoxy is excessively applied during bonding between the precast segments.