Retrofitting an existing building with base isolation requires
Answer: C
The load is transferred temporarily, the columns are cut in sequence and the bearings are inserted, which is demanding but well-established work. A moat and flexible services then have to be created around the completed plane.
Please log in or register to report this question.
Which of these is the correct order of increasing displacement demand across an isolation plane?
Answer: D
Displacement grows with the severity of the shaking, and the system is checked at the design level and again at the rarer maximum considered level. Restraints and additional gap are provided so that the larger event does not exhaust the bearings.
Please log in or register to report this question.
The seismic gap provided around a base-isolated building should be based on
Answer: A
Impact against the moat wall is a severe event for the superstructure, so the gap is sized for the rarer shaking rather than the design level. That is why the gap is normally larger than the design displacement itself.
Please log in or register to report this question.
Which of these best describes what an isolation system does to the input energy of an earthquake?
Answer: B
The impedance mismatch at the isolation plane keeps much of the energy from entering the building at all, and the bearings absorb a further share in hysteresis. What is left is small enough for the superstructure to carry elastically.
Please log in or register to report this question.
A tuned mass damper differs fundamentally from base isolation in that it
Answer: C
The auxiliary mass works with the structure's own response, absorbing energy once the building is already moving, whereas isolation prevents much of that motion from starting. The two are complementary rather than alternatives.
Please log in or register to report this question.
