Research on the Prevention of Brittle Fracture in High-Rise Steel Buildings

本研究的目的是澄清在1995年兵库县南部地震袭击现代都市期间观察到的钢结构建筑框架脆性断裂的原因。本研究的最终目的是提出一种设计方法，以防止脆性断裂，预计在高层建筑在地震多发区的城市地区。本研究主要探讨以下几个问题：1）钢结构的脆性断裂会造成多大程度的安全性降低？2)现代建筑高层钢结构的脆性断裂可能是什么样的模式？3)钢材料脆性断裂的主要特性是什么？4)焊接对钢连接的脆性断裂有什么影响？5)地震时的滞后变形对脆性断裂有什么影响？6)建筑物发生脆性断裂后如何实现失效安全机制？7)本研究结合现有的相关知识，为防止脆性断裂提供了先进的设计方法，在实验测试和分析模拟相结合的基础上，为上述问题提供了解决方案，也为脆性断裂提供了基础信息。综合这些资料，提出了初步的设计和施工方法。但是，地震时的脆性断裂现象是一个非常复杂的现象，涉及到许多物理因素，要得出最终的结论还需要进一步的研究。

This research aims at clarifying the cause of brittle fracture in steel building frames as observed during the 1995 Hyogoken-Nanbu Earthquake which hit the modern urban city. The final target of this research is to propose a design method to prevent the brittle fracture which is anticipated in high rise buildings in earthquake-prone urban areas. This research deals with the following subjects :1) How much degree of safety degradation is anticipated in steel structures by brittle fracture?2) What is the possible mode of brittle fracture in tall steel buildings of modern architecture?3) What is the governing property in steel material on brittle fracture?4) What effect is given by welding on brittle fracture of steel connections?5) What effect is given by hysteretic deformation during earthquake on brittle fracture?6) How failsafe mechanism is possible after occurrence of brittle fracture in buildings?7) How sophisticated design methodology can be provided for preventing brittle fracture from this research and current related knowledge.This research, on the basis of the combination of experimental test and analytical simulation, has provided resolutions to the above questions as well as basic information on brittle fracture. From synthesizing these data, a tentative design and construction method is proposed. However, it is also understood that the phenomenon of brittle fracture during earthquake is a very complicated one including many physical factors, then further research is required to attain the final conclusions.