Abstract
In this study, the investigations were conducted on the required fracture toughness of steels to prevent brittle fracture during earthquakes in steel bridge piers. By considering the scenarios of the occurrence of brittle fracture, the patterns of prestrain that should be considered were shown, and then the effects of various patterns of prestrain on fracture toughness of steels made to be clear by the development of the method to introduce prestrain into specimens. Finally, by arranging all the results of this study and our previous study on the effects of plastic prestrain, the level of the required fracture toughness was suggested. To prevent brittle fracture during earthquakes, the temperature shift of 50 degrees of Celsius of the critical CTOD curves by plastic prestrain should be considered.
