Seismic Rocking Isolation Effect on Superficial Foundations of Bridges

Student: Daniele Baffo
Supervisors: Prof. K. Kawashima

ABSTRACT

It was observed from the post-earthquakes investigations, that a number of structures resting on shallow foundation had escaped more serious damages by rocking on their footing pads. This report discusses the isolation effect of foundation rocking and uplift in bridges.

Firstly, are discussed some modelling issues related mostly to the foundation soil interaction and to the Winkler model parameters. Then, is studied a simple system (foundation, column and tributary deck) to investigate the effects of the footing uplift in the global response of the structure.

An alternative simplified approach to model the behaviour of the footing when uplift is allowed is presented, and it is compared with the results obtained applying the Winkler foundation model.

Secondly is presented the response of two different bridges: a urban bridge and a cross valley bridge. Are shown the effects of the foundation soil separation in the two different structural system, and were investigates the differences.

Finally was studied the effect of the pounding between the deck and the abutments in the footing rocking isolation.

You may download a digital version of this MSc dissertation here.