STUDY ON THE FRP CONFINING EFFECT ON REINFORCED CONCRETE BRIDGEPIERS WITH RECTANGULAR HOLLOW SECTION

Abstract

Abstract: High-piers of hollow section have been constructed in numerous spectacular reinforced concrete (RC) bridges, which can be an effective solution to maximize strength-mass and stiffness-mass ratios, and to reduce the weight contribution to the foundations and the mass contribution to the seismic response. Because of the wall thickness, ties or spirals reinforcements ratio, shear-span ratio, axial compression ratio et. al, the hollow RC piers designed in accordance with the old and existing codes were damaged in recent earthquakes due to insufficient flexural strength, shear strength or ductility. So in order to improve the seismic performance of the hollow bridge piers, the confinement effect on the behavior of RC bridge piers with fiber-reinforced polymer sheets (FRP) should be accurately estimated based on the seismic confinement theory of columns. According to this achievements, the confined performance of columns is obviously improved, and it is influenced by factors of the types of FRP sheets, FRP sheets thickness, the width and the space of FRP strips. In this paper, the finite element numerical simulation method was applied firstly. It is to study the behavior of FRP confined RC hollow bridge piers, such as the development laws of axial compression force, confined concrete compressive strain, stirrup and FRP tension strain. Based on the above simulated results, a new formula of lateral pressure with the complex confinement effect of FRP strips and stirrups was proposed, and then it is used to the compressive stress-strain model of FRP confined concrete. The formed compressive stress-strain model was further used to estimate the behaviors of FRP confined RC bridge piers with rectangular hollow cross section. The simulated results show that the curvature ductility, displacement ductility, ultimate deformation, ultimate strength are improved significantly. Then the calculation results was compared with experimental results, and it shows that the simulated results have good agreement with experimental results.

Key words: fiber reinforced polymer, confinement effect, lateral confinement pressure, confined concrete model, hollow section bridge pier

CLC Number:

LIU Ke, DONG Zhen-hua. STUDY ON THE FRP CONFINING EFFECT ON REINFORCED CONCRETE BRIDGEPIERS WITH RECTANGULAR HOLLOW SECTION[J]. Fiber Reinforced Plastics/Composites, 2016, 0(4): 12-20.

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