Base Isolation
We have proposed a fixed base system with base isolation which will provide the very best in earthquake safety, exceeding the original Turner budget estimate by approximately $2.7 million. The performance expectations of this recommended system are identified in the information below and contrasted with the traditional fixed base solution.
If a small, frequent event were to occur with 72 year return, a fixed base structure would receive no structural damage and a small chance of nonstructural damage. Such an event would have no effect on an isolated structure.
If a normal design event with 500 year return were to occur, a fixed base structure would have repairable structural damage expected and significant chance of nonstructural damage to equipment or piping and disruption to contents. An isolated structure would have no structural damage and no nonstructural damage. Some shifting of contents would occur.
If a maximum considered event with 1000 year return was to occur, a fixed base structure could expect structural damage and significant nonstructural damage. An isolated structure could expect its structural bearings to remain stable with the possibility of some damage to its superstructure. It could also expect nonstructural damage and disruption.