Performance in Shear of Concrete Bridge Piers/Columns Duringthe Northridge Earthquake

9416759 Sozen本项目对北岭地震期间观察到的桥墩剪切破坏进行了详细评估。 本研究的主要目的是为低至中等地震活动性地区的类似结构制定设计和加固标准。 众所周知，钢筋混凝土构件的抗剪强度的许多方面都知之甚少。 现有设计标准的适用性仅限于现有经验和实验中涉及的变量范围。 根据北岭事件的正反两方面经验，需要重新解释现有的抗剪强度程序和实验数据。 这样的研究是必要的，主要是因为观察到，可能的最大单位剪切应力所承受的桥墩在北岭地震剪切失败的决定性小于测量单位剪切强度的可比测试样本在文献中报道。 根据（a）现有的实验数据和（B）北岭事件期间受损和未受损桥墩的数据，对剪切强度的新旧假设进行评估。 一套适用于低至中等地震活动区域的类似结构的设计标准将根据本研究的结果进行组装。 这是一个北岭地震项目。 ***

9416759 Sozen This project conducts a detailed evaluation of shear failures observed in bridge piers during the Northridge Earthquake. The primary objective of this study is to develop design and strengthening criteria for similar structures in regions of low to moderate seismicity. It is well known that many aspects of the shear strength of reinforced concrete elements are poorly understood. Applicability of existing design criteria are limited to the ranges of the variables involved in available experience and experiments. A reinterpretation of the available procedures and experimental data for shear strength are needed in the light of both positive and negative experiences during the Northridge event. Such a study is needed primarily because of observations that probable maximum unit shear stresses sustained by bridge piers failing in shear during the Northridge Earthquake were decisively less than measured unit shear strengths of comparable test specimens reported in the literature. Old as well as new hypotheses for shear strength will be evaluated in the light of (a) existing experimental data and (b) data from damaged and undamaged piers during the Northridge event. A set of design criteria applicable to similar structures in regions of low to moderate seismicity will be assembled on the results of this study. This is a Northridge Earthquake project. ***