University at Buffalo - Low Aspect Ratio Rectangular Reinforced Concrete Shear Wall - Specimen SW3

Although low aspect ratio shear walls are widely used in buildings and safety-related nuclear structures, their hysteretic behavior, including peak strength and effective elastic stiffness, has not been adequately characterized to enable robust performance and risk assessment. The US National Science Foundation funded a Network for Earthquake Engineering Simulation (NEES) research project on shear walls of conventional and composite construction to better understand the seismic behavior of these widely used structural elements. A total of 16 rectangular, low aspect ratio concrete shear walls (12 conventionally reinforced concrete and four composite) were built and tested at the University at Buffalo (UB).

The goals of the project include validation of simulation tools and updating of numerical modeling procedures to more accurately predict the behavior of low aspect ratio walls with rectangular cross sections. Physical and numerical simulation results will be used to generate and update predictive strength and new code design equations, load-displacement relationships and macro-level hysteretic models. Fragility functions and damage states for use with next generation tools for performance-based earthquake engineering will be updated. Educational tools will be developed to effectively and efficiently explain the resistance and failure mechanism of low aspect ratio reinforced concrete shear walls.

The test data confirmed that design equations in codes and standards are unable to predict peak shear strength and that the scatter in the predictions is significant. The hysteretic response of the test specimens degraded quickly at cycles to displacement greater than that associated with peak strength, questioning the behavior of nuclear structures that incorporate shear walls for earthquake shaking more intense than design basis. The effective stiffness of the test specimens were substantially lower than those calculated using the predictive equations of ASCE 43-05 and ASCE 41-06, which is problematic for dynamic analysis, generation of in-structure floor response spectra, and risk assessment.

尽管低宽比剪力墙（low aspect ratio shear walls）已广泛应用于建筑及安全相关核结构中，但针对其滞回特性（包括峰值强度与有效弹性刚度）的表征仍不够充分，无法支撑可靠的性能评估与风险分析。美国国家科学基金会（US National Science Foundation）资助了地震工程模拟网络（Network for Earthquake Engineering Simulation, NEES）的一项研究项目，针对传统配筋与组合结构剪力墙展开研究，以期更深入理解这类广泛应用的结构构件的抗震性能。布法罗大学（University at Buffalo, UB）共制作并测试了16片矩形截面低宽比混凝土剪力墙，其中12片为传统配筋混凝土剪力墙，4片为组合结构剪力墙。

本项目的目标包括验证仿真工具、更新数值建模流程，以更精准地预测矩形截面低宽比剪力墙的力学行为。试验与数值仿真结果将用于生成并更新预测强度公式、新型规范设计方程、荷载-位移关系曲线以及宏观滞回模型。针对下一代基于性能的抗震工程工具所需的易损性函数与损伤状态参数也将得到更新。项目还将开发教育工具，以清晰高效地阐释低宽比配筋混凝土剪力墙的受力机理与破坏模式。

试验数据证实，现行规范与标准中的设计方程无法准确预测峰值抗剪强度，且预测结果的离散性显著。当循环加载位移超过峰值强度对应的位移时，试验试件的滞回响应快速退化，这对采用剪力墙的核结构在超过设计基准的强烈地震作用下的性能表现提出了质疑。试验试件的有效弹性刚度远低于依据ASCE 43-05与ASCE 41-06的预测公式计算得到的结果，这对动力分析、结构内楼层反应谱生成以及风险评估均会造成不利影响。