BASE ISOLATION METHOD IN BUILDING
Base Isolation Method in Building Construction
Conventional Construction Practice assumes Fixed Base Structures
- The Dynamic Characteristics of Fixed Base Structures are determined by the general characteristics of the structural system
- The Designer can only slightly adjust those Dynamic Characteristics
- As a matter of fact, most common Building Structures have unfavourable Dynamic Characteristics that result in increased Seismic Response
Earthquake Performance of Fixed Base Structures
- Conventional Fixed Base Structures can not be realistically designed to remain elastic in large seismic events (more so in regions of high seismicity)
- Common practice is to design them so that they experience damage in a controlled manner and have large inelastic displacements potential
Unconventional Earthquake Protective Systems
Base Isolation is the most common System
The Concept of Base Isolation
Significantly Increase the Period of the Structure and the Damping so that the Response is Significantly Reduced
Base Isolation in Buildings
Isolator Components between the Foundation and Superstructure
Fig: An Isolation Interface is formed
How exactly does Base Isolation Work?
Most types of Isolators exhibit nonlinear behavior
Lengthening of the Structure’s Period and increased damping that result in a large scale decrease of the Seismic Response.
Force – Displacement Relationship at the Isolation Interface
Response of Base Isolated Buildings versus Fixed Base Response
