Water Storage Tank Response To Earthquake Loads In Alaska - Predictive Modeling By The Finite Element Method

摘要

Alaska is one of the most seismically active areas in North America Large-scale seismic event occurrence is more than ten times greater than in California Approximately 40-50% of the communities with 60% of the total population are located m seismic zones 3 and 4, which are areas with the potential for high seismic nsk. Due to limited access and the isolated locations of many of these communities, a much greater reliance is placed on many of the essential, lifeline facilities. In addition, a much higher per capita investment exists in the facilities and any recovery effort or needed repairs are expected to be delayed, should wide spread damage occur. Extended periods of snow cover in Alaska increase the likelihood of coincident large snow loads with a seismic event. A recent trend in earthquake engineering of lifeline facilities is to design structures to a higher and more realistic level of performance. This concept grew out of the extremely large capital expenditures required to restore infrastructure after recent earthquakes in Northridge, California; Kobe, Japan- Turkey and Greece. Apphcation of advanced dynamic analysis methods has been limited to high cost large structures. The availability of software for personal computers allows performance based analysis and design of lifeline structures for lower cost projects m small communities. An example of this approach is used to evaluate the performance and response of a ground level steel water storage tank both with and without snow loads to determine whether a significant effect results A synthetic time history of the horizontal and vertical components of the 1964 Alaska Earthquake is used in the analysis. The computer program ANSYS is used for the finite element analysis (FEA) of the tank and contained fluid Results are then compared with code values.