Coupled Seismic Performance of Underground and On-Ground Structures

Abstract

AbstractSeismic performance evaluation of on-ground structures can be significantly affected by their interaction with underground structures. This effect becomes more relevant in densely populated areas where transportation systems such tunnel metro lines are located nearby urban overpasses, and buildings. This paper presents the findings of a numerical study carried out to conduct the seismic evaluation of a typical bridge-building-tunnel system, located in the high plasticity Mexico City clay. Through a series of three-dimensional finite difference numerical models developed with the software FLAC3D, both detrimental and beneficial interactions effects among these structures are analyzed, establishing zones around each structure in which this interaction leads to ground motion variability, as well as the impact on both the building and bridge seismic performance. The parametric study was carried out considering both normal and subduction events for a return period of 250 years. Distances among each structure was varied to cover a wide range of scenarios. From the results gathered in here, the effect of this interaction on the modification of surface accelerations, seismic demand in on-ground structures, as well as deformations and structural stresses in the tunnel lining was established.KeywordsSeismicSoil-structure interactionTunnelBridgeBuilding