Seismic Design of Tall Structures Considering Anchor-Bolt Yielding : Generation of Simplified Model and Numerical Response Analysis

This paper is the third report in our series of studies concerning the seismic design of tall structures such as reactor tower pressure vessels in chemical engineering plants and oil refinery complexes. Particular attention is paid to anchor-bolt yielding during earthquake excitations whose dynamic behaviour has been fairly precisely observed by shaking tests as described in the former report. In this specific work, we have proposed two types of simplified mechanical models (the single-degree-of-freedom slip-type model and the two-degree-of freedom rocking-type model) where-by inelastic energy-absorbing characteristics of the anchor bolt are simulated by referring to the experimental results. With the aid of these simplified models, numerical response analysis using the Runge-Kutta-Gill method is carried out under the similar conditions for shaking tests. As far as the structural response waveforms, inelastic loads and dynamic strains for the anchor bolts and energy-absorbing hysteresis curves are concerned, satisfactorily good agreement can be achieved between the testing results and the numerical simulation results.