ISSN: 1945-7545
CODEN: GTJODJ
Published Online: 1 September 2012
Page Count: 16

Centrifuge Modeling of Seismic Loading on Tunnels in Sand

Lanzano, Giovanni
Research Assistant, Univ. of Molise, Campobasso,

Bilotta, Emilio
Assistant Professor, Univ. of Naples Federico II, Naples,

Russo, Gianpiero
Associate Professor, Univ. of Naples Federico II, Naples,

Silvestri, Francesco
Professor, Univ. of Naples Federico II, Naples,

Madabhushi, S. P. Gopal
Reader, Univ. of Cambridge, CB2,

(Received 23 September 2011; accepted 11 June 2012)

Abstract

The purpose of the work is to provide an experimental benchmark on the seismic behavior of tunnels, with the final aim of calibrating numerical and analytical design methods. A series of plane-strain centrifuge tests with dynamic loading on a model tunnel was, therefore, carried out at the Schofield Centre of the Cambridge University Engineering Department (CUED). Four samples of dry uniform fine sand were prepared at two different densities, in which an aluminum-alloy tube was installed at two different depths. The tube was instrumented with strain gauges to measure hoop forces and bending moments at significant locations. To monitor the amplification of ground motion from the base to the surface, vertical arrays of accelerometers were placed in the soil model and along the box. The instrumentation also included linear variable differential transformers (LVDTs) that measured the soil surface settlement during all test phases. The test procedure and the results are described in this paper, showing the evolution of both accelerations and internal forces along the tunnel lining during the model earthquakes.

Keywords:
tunnel, centrifuge, earthquake, physical modeling

Paper ID: GTJ104348
DOI: 10.1520/GTJ104348
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