Faculty of Engineering, China University of Geosciences, Wuhan, China.
PLoS One. 2018 Jul 10;13(7):e0200072. doi: 10.1371/journal.pone.0200072. eCollection 2018.
Steel fiber is one of the most widely used reinforcements to improve the performance of concrete members. However, few studies have been proposed to study the seismic performance of bridge piers constructed with steel fiber reinforced concrete. This paper presents the collapse vulnerability assessment of typical single bridge piers constructed with steel fibers. Fiber element models of RC bridge piers with and without steel fibers are firstly built by selecting suitable cyclic constitutive laws of steel fiber reinforced concrete, and then calibrated using the experimental results. The seismic capacity and inelastic demand of RC piers with steel fibers are quantified using both nonlinear static pushover analyses and nonlinear incremental dynamic analyses (IDA). In order to conduct the IDA, a suite of 20 earthquake ground motions are selected and scaled to different levels of peak ground acceleration (PGA). Collapse fragility curves are then generated using the maximum drift ratio of piers as the engineering demand parameter (EDP). In order to investigate the impact of various parameters on the collapse fragility curves, six parameters are considered in the parametric study: peak compressive strength of concrete, yield strength of steel, longitudinal reinforcement ratio, axial load ratio, transverse hoops ratio and steel fiber content. It was observed that the concrete strength, longitudinal reinforcement ratio and steel fiber content could significantly affect the collapse fragility curve of the bridge piers with steel fibers.
钢纤维是提高混凝土构件性能最常用的增强材料之一。然而，很少有研究提出研究用钢纤维增强混凝土建造的桥墩的抗震性能。本文提出了用钢纤维增强混凝土建造的典型单桥墩的易损性评估。通过选择合适的钢纤维增强混凝土循环本构定律，首先建立了有无钢纤维的 RC 桥墩的纤维元模型，并使用实验结果对其进行了校准。利用非线性静力 Pushover 分析和非线性增量动力分析（IDA）定量评估了 RC 桥墩的抗震能力和非弹性需求。为了进行 IDA，选择了 20 组地震地面运动，并将其按不同的峰值地面加速度（PGA）水平进行缩放。然后使用桥墩的最大水平位移比作为工程需求参数（EDP）生成易损性曲线。为了研究各种参数对易损性曲线的影响，在参数研究中考虑了六个参数：混凝土的峰值抗压强度、钢材的屈服强度、纵筋配筋率、轴压比、箍筋配箍率和钢纤维含量。结果表明，混凝土强度、纵筋配筋率和钢纤维含量会显著影响带钢纤维的桥墩的易损性曲线。
