摘要
建筑物中柱和桥墩的修复设计要求对结构变形能力进行精确预测。本文提出分析模型近似计算经纤维增强聚合物修复的钢筋混凝土柱的潜在塑性关键区的延展性。提出能够代表纤维增强聚合物混凝土响应的双线性应力-应变模型,该模型在低压下混凝土响应降低,在高压下混凝土响应增强。对于承受轴力和弯矩的圆柱,模型采用近似形式的组合分析,根据无量纲柱参数和纤维增强聚合物提供的约束压力来计算经纤维增强聚合物修复的截面延展性。通过比较组合分析的模型估计结果和试验结果,验证纤维增强聚合物修复柱延展性模型的精确性。随后,建立了循环桥柱纤维增强聚合物简单非重复抗震修复设计程序。最后,对不同轴向荷载、含筋率、纤维增强聚合物数量进行典型桥柱参数研究,计算结果以无量纲形式给出,有助于工程师采用纤维增强聚合物进行提高柱延展性的抗震修复设计。
Retrofit design of existing columns in buildings and bridge piers necessitates the accurate prediction of the deformation capacity of structures. In this study, an analytical model is proposed to estimate the ductility of potential plastic hinge regions of RC columns after a fiber reinforced polymer （FRP） retrofit. A simple bilinear stress-strain model that is capable of representing an FRP concrete response exhibiting softening at low confining pressures and hardening at higher confinement is proposed. This model is then employed in an approximate closed form sectional analysis of circular columns subjected to axial force and bending moment. Section ductilities that can be obtained as a result of FRP retrofit are expressed in terms of non-dimensional column parameters and confining pressure supplied by FRPs. The accuracy of the model to estimate the ductility of FRP retrofitted columns is verified by comparing model estimations with sectional analysis and test results. Subsequently, a simple non-iterative seismic retrofit design procedure using FRPs is established for circular bridge columns. Finally, parametric studies are conducted on a typical bridge column for different axial loads, reinforcement ratios and FRP amounts. Results are presented in the form of non-dimensional plots to aid engineers in the FRP retrofit design of columns for ductility enhancement.
出处
《钢结构》
2008年第9期85-86,共2页
Steel Construction
关键词
纤维增强聚合物
抗震修复
约束
延展性
Fiber reinforced polymers
Seismic retrofit
Confinement
Ductility
