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

这是一个事后调查项目，目的是从洛马普里埃塔地震(1989年10月)中吸取工程经验教训。洛马普里埃塔地震导致地面和高架坦克发生大量损坏事件，甚至一些改装的坦克也受到损坏。特别是，长周期地面运动分量的场地放大似乎是建造在海湾泥浆上的油罐大幅晃动和相关损坏的原因。在本项目中，将对收集的数据进行分析，以评估储罐结构的性能。这些任务包括：(1)收集地面储水罐和石油储罐以及高架储水罐所受损害的数据和文件，(2)计算有代表性的储水罐的动态响应，并将计算的响应与观察到的损坏或无损坏相关联，(3)研究长周期部件的现场放大对海湾泥基储罐晃动现象和摇摆运动的影响；(4)对改装后的储罐进行损坏研究，以推断实施的改装机制无效的原因。(5)诱发地震力与API650、AWWA100、UBC等现行规范和标准规定的地震力进行比较。通过将预测响应与地震荷载下的实际行为进行比较，将改进用于储罐响应计算的分析方法，并将制定改进的设计程序。

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.