Sliding Pendulum Bearing with Dual Load-Case Sliding Surfaces
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Solution Overview
Problem
Conventional sliding pendulum bearings exhibit non-linear isolation behavior, leading to poor performance at peak ground acceleration values different from the design basis, resulting in inadequate protection against earthquakes and increased construction damage.
Innovation Solution
Designing the first and second main sliding surfaces for different load cases, with the first surface optimized for peak ground acceleration values up to the maximum credible earthquake and the second surface for values below the design basis, ensuring a linear isolation behavior and improved displacement capacity management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sliding pendulum bearing is designed for a specific peak ground acceleration value, then the isolation effect is optimized for that specific load case, but the isolation performance deteriorates at peak ground acceleration values different from the design basis
Solution Approach 1:
The bearing is divided into two separate sliding surfaces, each optimized for a specific load case (first sliding surface for higher peak ground accelerations up to maximum credible earthquake, second sliding surface for lower peak ground accelerations up to design basis earthquake). This segmentation allows the bearing to handle multiple earthquake scenarios effectively, resolving the contradiction between optimizing for a specific load case and maintaining performance across different load cases
Solution Approach 2:
Each sliding surface is given different local properties (different coefficients of friction, different radii of curvature) tailored to its specific load case. The first sliding surface has properties optimized for high-intensity earthquakes while the second sliding surface has properties optimized for low-intensity earthquakes, allowing each part to perform its specific function optimally
2Reliability
If the radius of curvature of the sliding plate is increased to maximize isolation effect, then the isolation effect is improved, but the displacement capacity required increases leading to larger bearing dimensions
Solution Approach 1:
The total displacement capacity is segmented between two sliding surfaces. Each surface handles a portion of the total displacement, allowing the use of smaller radii of curvature compared to a single surface design. This reduces the overall bearing dimensions while maintaining the isolation effect
Solution Approach 2:
The bearing utilizes different coefficients of friction and radii of curvature for the two sliding surfaces. By changing these parameters appropriately for each surface, the bearing achieves effective isolation without requiring excessively large displacement capacities, thus reducing bearing dimensions
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 approach enhances the isolation behavior of the sliding pendulum bearing to match that of optimized viscous damping systems, reducing construction damage and costs by maintaining better isolation across a wider range of peak ground acceleration values without excessive bearing movement.
Implementation Method 1
the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate
Data Source
AI summary
A sliding pendulum bearing is used to protect a construction against dynamic stresses from predominantly horizontal earthquake excitation with a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case.