Record Details
Review of guidelines for the design of tsunami vertical evacuation buildings
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Review of guidelines for the design of tsunami vertical evacuation buildings |
| Names |
Cawley, Jessica Grace
(creator) Barbosa, Andre R. (advisor) Yeh, Harry H. (advisor) |
| Date Issued | 2014-03-20 (iso8601) |
| Note | Graduation date: 2014 |
| Abstract | Tsunamis have the potential to inflict severe damage and loss of life in coastal communities. Structures known as vertical evacuation buildings provide an alternative evacuation site for communities living in relatively flat, coastal regions with inadequate sources of high ground for evacuation. Design of these structures balances risk and economy, and requires both technical and social design considerations. The design must be ductile enough to resist seismic vibrations and also strong enough to resist static and hydrodynamic loads and impact forces from floating debris. Uncertainties in the tsunami wave characterization and force determination promote over-conservative designs which may be cost-prohibitive to build. Previous to the March 11, 2011 earthquake and tsunami in Japan, well-engineered reinforced concrete structures were thought to withstand tsunamis; however, in the 2011 event, many engineered reinforced concrete buildings failed as the tsunami forces were greater than anticipated. In order to properly determine the forces on a structure, the tsunami waves must be adequately characterized; this process is called the Tsunami Hazard Analysis. The key factors used to characterize tsunamis are identified and their imbedded uncertainties are discussed. The Tsunami Hazard Analysis can provide a range of precision in its output values and therefore a tiered approach to the Tsunami Structural Analysis that follows the Tsunami Hazard Analysis is proposed. In the Tsunami Structural Analysis, the velocity and height parameters characterize the tsunami and are used to determine the actual forces on a structure. Three tiers have been provided based on the information available for the site based on the tsunami hazard assessment: Tier 1 includes only runup elevation or height parameters of the tsunami inundation. Tier 2 includes detailed depth and velocity information provided from a numerical model of the area. Tier 3 includes a time series of depth and velocity information and may use a fluid-structure interaction numerical model to determine the forces directly. The first two tiers can be found in various forms in existing guidelines. The third tier is recommended for important facilities such as tsunami vertical evacuation buildings. The existing methodologies in the guidelines for the design of Vertical Evacuation Buildings, such as FEMA P-646, are reviewed. Their advantages, uncertainties, and limitations in the context of the discussions on Tsunami Hazard Assessment and Tsunami Structural Analysis are discussed. Based on the findings of this research, a tiered design rationale is proposed in order to clearly categorize uncertainties in the force estimation process. In addition to the rationale, main conclusions of this research include: (1) tsunami parameter clarification, including assumptions/applicability of different depth, velocity, added mass coefficients, among other parameters; (2) identification of need for flow parameter (h²u²)[subscript max] for computing overturning moments with reduced uncertainty; (3) building shape effects, for example U-shaped building coefficients need to be developed for the estimation of drag force and also in the determination of realistic and governing tsunami force combinations; and (4) identification and applicability of critical flow conditions as well as appropriate force combinations. The four topics above are important to mitigate risk in the design of vertical tsunami evacuation buildings and to promote economical designs that are feasible for many communities. |
| Genre | Thesis/Dissertation |
| Access Condition | http://creativecommons.org/licenses/by/3.0/us/ |
| Topic | Tsunami |
| Identifier | http://hdl.handle.net/1957/46968 |
