Comparative response assessment of minimally compliant low‐rise conventional and base‐isolated steel frames

Abstract

In this study, the multi-intensity seismic response of code-designed conventional and base-isolated steel frame buildings is evaluated using nonlinear response history analysis. The results of hazard and structural response analysis for three-story braced-frame buildings are presented in this paper. Three-dimensional models for both buildings are created and seismic response is assessed for three scenario earthquakes. The response history analysis results indicate that the design objectives are met and the performance of the isolated building is superior to the conventional building in the design event. For the Maximum Considered Earthquake, isolation leads to reductions in story drifts and floor accelerations relative to the conventional building. However, the extremely high displacement demands of the isolation system could not be accommodated under normal circumstances, and creative approaches should be developed to control displacements in the MCE.

Performance of base‐isolated reinforced concrete buildings under bidirectional seismic excitation considering pounding with retaining walls including friction effects

“…A coupled plasticity model, with a circular yield surface is used for bidirectional lateral response of these elements [35]. The vertical force-deformation relationship (Figure 3(b)) of each element was simulated using a linear elastic spring with stiffness K v = 1.65 × 10 6 kN/m in compression and 0.01 K v in tension [12]. Here, for each bearing element, for the LB properties (UB properties), initial stiffness K 1 = 5,945.5 kN/m (8,858.7 kN/m), yield force F y = 111.4 kN (133.7 kN) and α = K 2 /K 1 = 0.1, where K 2 is the post-elastic stiffness.…”

“…Here, for each bearing element, for the LB properties (UB properties), initial stiffness K 1 = 5,945.5 kN/m (8,858.7 kN/m), yield force F y = 111.4 kN (133.7 kN) and α = K 2 /K 1 = 0.1, where K 2 is the post-elastic stiffness. The vertical force-deformation relationship (Figure 3(b)) of each element was simulated using a linear elastic spring with stiffness K v = 1.65 × 10 6 kN/m in compression and 0.01 K v in tension [12].…”

“…The effect of bidirectional horizontal excitation on base-isolated buildings is an important issue and has been mostly studied in the past without considering seismic pounding (see, for example, [10][11][12][13]). Whereas most of these studies focus on the response of the isolation system by adopting rigid or linear elastic models for the superstructure, the study by Erduran et al [12] focuses on the multi-level seismic response of a steel superstructure through three-dimensional models considering nonlinear behavior of the superstructure as well as the isolation system. Multi-level seismic response evaluation is important in performance-based earthquake engineering.…”

Performance of Isolated Buildings with Superelastic-Friction Base Isolators under High Seismic Hazards

“…Erduran et al (2011) found that extremely high isolator deformation demand are present in the isolated buildings under MCE level seismic events regardless of superstructure design. Large isolation displacements indicate the need for larger size isolation devices and seismic gaps and increase the potential of impact or pounding of a structure with adjacent building.…”

Extreme behavior in a triple friction pendulum isolated frame

“…A handful of numerical studies have looked at the performance of isolated buildings, up to and including collapse, some with the purpose of lifetime cost assessment. However, these studies do not include extreme bearing behavior or restriction from seismic moats; isolators were allowed to displace indefinitely.…”