Experimental Study On Seismic Behavior Of Rectangular Hollow Pier

In order to clarify the behavior of RC hollow rectangular piers under combination of axial loads and earthquake loads:designed4rectangular hollow piers with different axial compression ratio and different transverse reinforcement ratio and it designed to be failed in flexural.The main results of the experimental studies conducted on4specimens with height1800mm are reported herein. The rectangular hollow piers test units, designed with two layer of longitudinal reinforcement where the first layer near the outside face the other on near the inside face, and transvers had the same thing. These units were subjected to constant compressive axial load and cyclically varying lateral load. Theoretical aspects of the shear strength degradation with increasing lateral displacement are approached with recently developed shear strength models, and with the Modified Compression Field Theory.The cyclic loading test was carried out and comparing between the specimens results and this comparing included two parts; first, between the specimens have the same stirrup ratio with different axial compression ratio; second, between specimens having the same axial compression ratio and different stirrups ratio. The results of this test were the increasing transverse reinforcement ratio will improve the ductility factor and also the rectangular hollow piers had a good resistance for seismic loads.Using the OpenSEES(Open System for Earthquake Engineering Simulation) analytical program to simulate the specimens and made a comparison for the simulated results with experimental results in Skelton curve and hysteresis curve; and it shows a good agreement between experiment and simulation results.Also a theoretical shear capacity were conducted as a part of the research program on rectangular hollow piers, where choose four different theoretical shear capacity models which they are:Priestley model (ACI), ATC-32model (Applied Technology Council), Caltrans model (California Department of Transportation)(AASHTO), and Chinese model (highway bridge seismic design model). Then compared the theoretical shear results with the experimental results to show that appropriate design details can ensure good performance also when these members are subjected to seismic loads, and the specimens has failed in flexural too. The purpose Effects of different axial compression ratio and stirrup ratio on rectangular hollow pier along the bridge to the ductility performance law; Study the compatibility of the practical results with simulation results. Theoretical shear capacity were conducted as a part of the research program on rectangular hollow piers, to show that appropriate design details can ensure good performance, and, the present work is to develop easy to build and cost-effective structural members to be used for large highway bridges.This type of structural member presents several advantages when compared to solid columns due to the reduced mass per unit length afforded by the reduced section area. Disadvantages depend upon the possibility to ensure appropriate concrete confinement while keeping simple construction procedures.In general predictions of the behavior and of the failure mode are compared with the experimental results, showing good agreement. Although the hysteresis response was stable and the pier can dissipate energy under the earthquake, the behavior might become complicated by random loading process.All units had been failed in flexural mode, and from the static cyclic loading tests shows reasonable shear capacity. But the reduction in concrete shear resistance should be considered under the cyclic loading. Therefore it is essential to establish a rational shear design method which takes into account the shear resistant mechanism under the reversed cyclic loads.