Damage Analysis of Ground-Based and Elevated Tanks During the 1989 Loma Prieta Earthquake

这是一个事后调查项目，旨在从1989年10月洛马普列塔地震中吸取工程教训。洛马·普里塔地震对地面和高架坦克，甚至对一些改装过的坦克造成了大量的损坏。特别是，长周期地震动分量的现场放大似乎是造成海湾泥上建造的储罐的大振幅晃动和相关损坏的原因。在这个项目中，收集的数据将被分析，以评估水箱结构的性能。这些任务包括：(1)收集地面储水罐和储油罐以及架空储水罐所受损害的数据和文件；(2)计算具有代表性的储水罐的动力响应，并将计算响应与观测到的损坏或未损坏的相关性；(3)研究长周期构件的场地放大对建立在Bay Mud上的储罐晃动现象和摇摆运动的影响；(4)研究改造储罐的损伤，推断实施改造机制无效的原因；(5)与API 650、AWWA 100和UBC等现行规范和标准规定的感应地震力进行比较。通过地震荷载作用下的预测响应与实际性能的比较，将改进储罐响应计算的分析方法，并改进设计程序。

This is a post-event investigation project to learn engineering lessons from the Loma Prieta earthquake (October 1989). The Loma Prieta earthquake induced munerous incidents of damage to both ground-based and elevated tanks, and even to some of the retrofitted tanks. In particular, site amplification of long period ground motion components appears to be the cause of large amplitude sloshing and associated damage to tanks built on Bay Mud. In this project the data collected will be analyzed to evaluate the performance of tank structures. The tasks include: (1) collection of data and documentation of the damage sustained by ground-based water and petroleum storage tanks and by elevated water storage tanks, (2) calculation of the dynamic response of representative tanks and correlation of the computed response with observed damage or lack of damage, (3) study of the effects of site amplification of long period components on the sloshing phenomenon and on rocking motion of tanks founded on Bay Mud, (4) study of the damage to retrofitted tanks to deduce the reasons for the ineffectiveness of the implemented retrofit mechanisms, and (5) comparison of induced seismic forces with those specified by available codes and standards such as API 650, AWWA 100 and UBC. By comparison of the predicted response with actual behavior under earthquake loading, the analytical methods developed for response calculation of tanks will be refined and improved design procedures will be developed.