PolySDL-STRUCTURAL DESIGN LAB
at Florida Polytechnic University
Active learning in Civil Engineering through structural design, modeling, testing, and experimentation
Base isolation in action
A design-build-test activity on seismic response and vibration reduction
Why This Activity Matters
Base isolation is one of the most important ideas in earthquake engineering because it changes how ground motion is transferred into a structure. This activity helps students understand that seismic design is not only about increasing strength, but also about controlling motion and reducing the response of the building above the foundation.
Connection to Seismic Design
This activity connects to structural dynamics, earthquake engineering, seismic design, vibration control, and structural response. It helps students build intuition for how engineers can reduce seismic demand by modifying the interface between the structure and the ground.
Activity Status
In Development
Main focus
Base Isolation, Seismic Response, Structural Vibration Reduction
Course Connection
Structural Analysis, Structural Dynamics
Tools / Platforms
Model Fabrication, Physical Testing, Observation, Video Comparison
Activity Type
Design-Build-Test
Team Format
Groups of 5
Mode
Physical
Key Deliverables
Isolation Concept, Fabricated Model, Test Participation, Reflection Report
Technical Snapshot
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Comparison setup: Two identical model buildings experience the same shake-table motion.
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Superstructure: Four threaded-steel rod columns support a wooden roof platform with an elevated mass.
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Fixed-base model: Ground motion is transferred directly into the structure.
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Base-isolated model: A team-designed isolation layer allows controlled horizontal movement beneath the building.
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Main design variables: Isolation material, stiffness, friction, restoring force, stability, and load capacity.
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Responses studied: Roof motion, transmitted acceleration, isolation displacement, and overall stability.
The Design Challenge
Student teams are asked to design and fabricate test-ready structural models that incorporate different ideas for base isolation. Rather than using only one predefined isolation system, teams are encouraged to explore different concepts such as rubber, foam, marbles, rollers, or other creative mechanisms that may reduce the transfer of motion into the structure.
Each group must make sure that its isolation system satisfies two competing requirements: it must be flexible enough to provide isolation, but also stable and strong enough to support the weight of the structure above. The completed models are then tested and compared to observe how different isolation strategies influence structural response.
The goal is to help students understand not only what base isolation is, but also the practical challenges involved in making it work.
Full details regarding group variations, specimen geometry, materials, connection type, analytical prediction, fabrication, testing, and final deliverables are provided in the Structural Design Lab Activities Handbook.
Related Photos and Project Examples
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Selected images from related fabrication, testing, or previous project examples.