NEESR II: Mitigating the Risk of Coastal Infrastructure through understanding Tsunami-Structure Interaction and Modeling

Oregon State University, Corvallis OR

Investigators

Abstract

This award is an outcome of the NSF 08-519 program solicitation ''George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)'' competition and includes the Oregon State University (lead institution), Colorado State University (subaward), and Texas A&M University, Kingsville (subaward). The current tsunami evacuation strategy in the U.S. puts large populations at high risk because it requires everyone to evacuate the flooded areas and does not consider the possibility of using tall buildings for shelter. Part of the unwillingness to adopt vertical evacuation strategies stems from an inability to estimate the damage level in the flooded area for a range of building types, including reinforced concrete (e.g., modern hotel), unreinforced concrete masonry units (e.g., older motel, light commercial) and light-frame wood (mostly residential and some light commercial) structures. The goal of this project is to model building damage by studying water flow and debris hazard of collapsed buildings in the flooded areas. This will help us understand the expected damage to cities and town and to design buildings to withstand these forces. As a first step of this new approach, we will focus on residential (light-frame wood) buildings which make up 90% of the building stock in the US and are where people spend approximately half of the hours in their day, Because of the sheer number of residential buildings in these coastal communities, understanding tsunami impact on these structures and the expected damage level is necessary to reduce damage and loss of life. The goals of this NEESR-II project are to (1) develop a methodology to assess the risk of residential structures to tsunami inundation and wave forces through a systematic experimental study coupled with a numerical probability of failure analysis; (2) enable the development of innovative retrofit products by developing a structural testing protocol that is representative of hydraulic impact/forces during a tsunami; and (3) refine the current hydraulic force equation in ASCE 7 based on a series of wave basin tests to account for building density and other variables. This transformative project builds on the knowledge base of tsunami inundation at regional scales and the tsunami-structure understanding at the building scale from other NEESR projects. This project also integrates new large-scale physical modeling and numerical modeling efforts to mitigate both structural risk to building damage and loss of life in a community-wide tsunami inundation event. To accomplish the project objectives, several large-scale tests will be conducted over three years at the NEES Tsunami Facility at Oregon State University using both the Large Wave Flume and Tsunami Wave Basin Facilities. The tests will mark the first time that large-scale tsunami tests will be conducted for US residential structures. This project develops a collaboration with the Port and Airport Research Institute (PARI), Japan's premier research center for coastal infrastructure. Currently, the Tsunami and Storm Surge Division of PARI is developing a series of nested numerical models that can model tsunami propagation and inundation over a wide range of spatial scale, including tsunami forces on buildings. This project will have an important educational aspect by training two graduate students, one at Oregon State and the other at Colorado State, and one undergraduate research student per year from Texas A&M University-Kingsville, a minority serving institution. This research will permeate to basic undergraduate and graduate engineering courses at OSU, CSU, and TAMU-Kingsville to increase awareness of the engineer?s role and responsibility in the design of houses and buildings exposed to the forces of nature. Outreach aspects of this project will also focus on the use of technology to enhance learning via a hands-on design project related to tsunami-structure interaction for first year engineering students at universities outside the NEES@OSU site. In addition to this activity, the project as a whole will reach the general public through collaborations with two nationally known Museums of Science and Industry: one in Portland, OR, and the other in Chicago, IL. The project team will help the Chicago museum develop tsunami content for Science Storms, a high-visibility, marquee exhibit at the Museum, which welcomes over 1.5 million visitors, students, parents and teachers each year. The team will work with the Oregon museum on communicating the importance of engineering research to the general public. The project also supports one science teacher on the use of technology to enhance the learning of STEM subjects. Data from this project will be made available through the NEES data repository (http://www.nees.org)