Seismic Damping System with Uplift Restraint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional base isolation systems for seismic protection are complex, costly, and often unsuitable for lower-value structures due to their requirement for specialized installation and lack of vertical restraint, making them inaccessible to residential buildings and other low-value structures.
Innovation Solution
A seismic damping system comprising upper and lower rail members, a connector bracket, and uplift restraint members that allow bi-directional horizontal movement while providing vertical restraint, reducing inertial forces and preventing structures from being lifted off their foundations during seismic events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional base isolation systems are used, then seismic protection is provided, but the system becomes complex and costly
Solution Approach 1:
The base isolation system is divided into separate functional components: rolling elements for horizontal movement, friction elements for energy dissipation, and uplift restraint elements for vertical stability. This segmentation allows each component to perform its specific function independently, simplifying the overall system while maintaining effectiveness.
Solution Approach 2:
The base isolation system integrates multiple functions into a unified structure that simultaneously provides horizontal movement capability, vertical restraint, and energy dissipation. The connector bracket and bearing members serve multiple purposes including structural support, motion accommodation, and force transmission, reducing the need for separate specialized components.
2Reliability
If conventional base isolation systems are used, then seismic protection is provided, but specialized installation techniques are required
Solution Approach 1:
The system components are designed as discrete, modular units that can be independently installed and adjusted. The rolling elements, friction elements, and uplift restraint elements can be separately positioned and secured, allowing for simpler installation procedures compared to integrated conventional systems.
Solution Approach 2:
The base isolation system incorporates self-aligning and self-adjusting mechanisms through the rolling element design and connector bracket configuration, reducing the need for specialized installation techniques and allowing standard construction practices to be used.
3Adaptability or versatility
If conventional base isolation systems are used, then horizontal movement is allowed, but vertical restraint is insufficient
Solution Approach 1:
The system separates horizontal and vertical functions into distinct components: rolling elements handle horizontal movement while uplift restraint elements specifically address vertical stability. This functional segmentation allows each subsystem to be optimized for its particular purpose without compromising the other.
Solution Approach 2:
Uplift restraint elements are specifically designed to counteract vertical uplift forces generated during seismic events. These elements provide targeted resistance to upward forces that could lift the structure off its foundation, balancing the horizontal movement capabilities provided by the rolling elements.
4Force
If conventional base isolation systems are used, then inertial forces are reduced, but the system is limited to high value structures
Solution Approach 1:
The base isolation system uses readily available materials and standard construction components rather than expensive specialized elements. The rolling elements, friction elements, and connector brackets can be constructed from common structural materials, significantly reducing the overall cost while maintaining the ability to reduce inertial forces during seismic events.
Solution Approach 2:
The system allows for adjustable parameters such as the coefficient of friction, rolling element dimensions, and uplift restraint spacing that can be optimized for different structural values and seismic risk levels. This adjustability enables the same basic system design to be applied across a wide range of building types and values without requiring complete redesign.
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 system effectively reduces horizontal acceleration and inertial forces on structures, providing protection against seismic damage while being simpler and less costly to install, making it suitable for a wider range of buildings, including residential structures.
Implementation Method 1
The upper bearing member may be disposed between a first pair of opposing walls of the connector bracket and configured to slide or roll against the first concave surface in the first direction during seismic motions
Implementation Method 2
The first concave surface may face in a downward direction and define a first rolling or sliding path in a first direction
Implementation Method 3
The first uplift restraint member may extend inwardly from one of the walls of the first pair of opposing walls and may be received in the first groove
Data Source
AI summary
A system for damping seismic motions transmitted from a foundation to an architectural structure is disclosed. During a seismic event, the seismic damping system may permit bi-directional horizontal movement of the foundation relative to the architectural structure, while simultaneously providing the architectural structure with uplift restraint. The seismic damping system may include upper and lower rail members connected to each other via a bearing assembly. Respective concave surfaces may be formed in the upper and lower rail members to define first and second rolling or sliding paths for the bearing assembly. To limit vertical movement of the architectural structure during seismic motions, the bearing assembly may incorporate uplift restraint members for engaging the upper and lower rail members. Methods of assembling and operating such seismic damping systems are also disclosed.