The impact of a PEER funded research project, "Tsunami-borne Debris Loading on Bridges" is highlighted below. The project Principal Investigator (PI) is Ian Buckle, Foundation Professor, University of Nevada, Reno. The research team includes Denis Istrati, Research Assistant Professor, UNR, Seddigheh (Anis) Hasanpour, Graduate Assistant, UNR, and Michael Scott, Oregon State University, Corvallis.
Widespread damage to coastal bridges in recent tsunamis (Indian Ocean, 2004, and East Coast Japan, 2011) have shown the vulnerability of these structures to tsunami overtopping and the crippling socioeconomic impact of their loss on both emergency response and long-term recovery of the affected communities. Developing design guidelines for coastal bridges subject to tsunami overtopping has therefore become a priority and large-scale experimental and numerical simulations have been conducted to develop and validate tsunami design equations. But this work has been limited to clear-water conditions. The goal of the present effort is to study the effect of tsunami-borne debris on these design loads using the Large-Wave Flume at Oregon State University in Corvallis.
This work will be informed by high-end numerical simulations. In particular, the objectives of this study are to:
- Understand the two-fold effect of debris: (a) impact and (b) damming on bridges, for (i) small-size debris objects such as construction material, and (ii) large-size debris objects such as containers and ships.
- Examine the effect of multi-object debris, which is a more realistic case than single-object debris.
- Decipher (a) debris-wave interaction during debris transport, and (b) debris-wave-bridge interaction during the tsunami inundation of two types of bridges, a T-girder and a box-girder bridge. Although both types of bridges are expected to sustain the same impact force, the damming force could change, especially for small-to-moderate sized debris trapped between the girders of a T-girder bridge.
- Develop a high-quality experimental database that could be used by PEER and other research teams around the world for development and validation of numerical tools, to advance PBTE for coastal bridges.
- Develop and test possible counter-measures for new and existing bridges against debris loading.
- Contribute to the development, calibration and validation of the particle finite element method (PFEM) in OpenSees for simulating the tsunami debris impact on bridges.
- To the extent possible, compare results mesh-based (FEM), particle-based (SPH) and hybrid particle-mesh based method (PFEM) numerical methods for simulating (a) debris transport, (b) debris impact, and (c) debris damming, and identify the limitations of each method
- Evaluate (a) available simplified equations for debris loading on buildings (ASCE 7, FEMA P-646), and (b) the simplified debris loading equations for bridges recently developed using engineering judgment in the PEER pooled-fund, design guideline project for coastal bridges (TPF-5(307)).