3–storey building subjected to reverse faulting: Analysis and experiments: Fid-Bau Portal

3–storey building subjected to reverse faulting: Analysis and experiments

Fadaee, M. / Hashemi, K. / Farzaneganpour, F. / Anastasopoulos, I. / Gazetas, G.

Abstract The paper studies the response of a 3-storey building subjected to reverse faulting. 1 g physical model tests are conducted using a $3 m$ long split-box, modelling the nonlinear response of structural members with artificial plastic hinges. The experimental results are used to validate the numerical modelling technique, which is subsequently employed to conduct a parametric study on sand density, foundation type (isolated footings, strip and slab foundations), and the location and angle of fault crossing. It is shown that the response of the structure is sensitive to the relative location of the fault rupture. In the case of isolated footings, complex interaction mechanisms develop, including fault rupture diversion, bifurcation, or diffusion. While the rigid-body rotation of the structure $θ_{r}$ is crucial in terms of serviceability, the footing rotations $θ_{f}$ are responsible for superstructure distress. Such distress is directly related to differential footing rotations and displacements. Looser soil may act as a cushion, but its effect is not always beneficial. Bifurcation of the fault rupture may lead to outcropping of a secondary branch between the footings, with obvious detrimental consequences. Strip footings or a slab foundation offer substantial improvement. Such rigid and continuous foundation systems prohibit differential displacements between columns, forcing the entire structure to rotate as a rigid body. The interaction mechanisms are complicated further when the fault rupture crosses the structure at an oblique angle. The distress of the structure is reduced with strip footings, which should be installed in both directions.

Highlights • Investigation of the performance of an existing structure subjected to reverse faulting by 1g physical model tests. • Modelling the nonlinear response of structural members with artificial plastic hinges. • Employing calibrated numerical modelling to conduct a parametric study. • Sensitivity of the structure response to the relative location the outcropping fault rupture.