Making Evaluation System of Seismic Resistance for Concrete Structures

本研究的目的是利用三维非线性动力反应分析方法，以结构尺寸和结构部位地震波所获得的地震动为输入数据，建立城市混凝土结构抗震评价体系。(1)利用工程基岩上表面非平稳强震时程模拟技术Empr，建立了2003年兵库县南部地震、东海、东海假想地震及其耦合地震、三陆地震和东京地震的地震波。然后利用地面反应分析(FDEL)得到了这些地震在结构部位的地震动谱，即FDEL，它考虑了剪切刚度和阻尼值随频率变化的等效应变特征。(2)改进和扩展了三维非线性动力反应分析计算程序，考虑了高强钢筋的影响。对少量腹筋的钢筋混凝土梁进行了试验，将无腹筋混凝土梁的抗剪强度(Vc)和腹筋混凝土梁的抗剪强度(Vs)与试验的抗剪强度(Vu)进行了比较。综上所述，叠加法(VC+VS)适用于评估少量腹筋梁的抗剪强度。(3)研究发现，结构部位的地基条件、地面运动主频和峰值后的波形图是评估混凝土结构抗震性能的重要参数。

The purpose of this study is to make an evaluation system of seismic resistance for concrete structures in urban area using three dimensional nonlinear dynamic response analysis whose input data are structural dimensions and seismic ground motion obtained from the seismic wave at the structure location.The following studies were conducted in this research.(1) The seismic waves of Hyogo-ken nanbu Earthquake, the hypothetical earthquakes of Tokai, Tounankai and their coupled earthquake, Sanrikuminami Earthquake, and Tokachioki Earthquake in 2003 were developed using the simulation technique, EMPR, for non-stationary strong motion time histories on the upper surface of so-called engineering basemental rock. Then the seismic ground motions of these earthquakes at the structure location were obtained using the ground response analysis, so-called FDEL, which incorporates the erect of frequency dependent equivalent strain characteristics on the shear rigidity and damping.(2) The computer program of three dimensional nonlinear dynamic response analysis was improved and extended to consider the high strength reinforcement. The reinforced concrete beams with a small amount of web reinforcement were tested in order to compare the estimated shear strength calculated by summing up the shear strength of concrete beams without web reinforcement (Vc) and web reinforcement (Vs) to the tested shear strength (Vu). In conclusion, the superposition method (Vc+Vs) is applicable for estimating the shear strength of beams with a small amount of web reinforcement.(3) From this research it is found that the ground condition at the structure location, dominant frequency of ground motion, and wave profile after the peak of ground motion are important parameters to evaluate the seismic resistance for concrete structures.