3rd Croatian Conference on Earthquake Engineering 3CroCEE

In this paper are presented original results obtained from the realized well targeted laboratory tests of nonlinear response of the constructed large-scale prototype models of circular RC bridge piers under realistically simulated earthquake-like cyclic bending and different levels of the induced axial loads.
Considering the obtained detailed results from the integral experimental investigation of the hysteretic behavior of RC bridge pier models with common circular cross-sections under simultaneously applied constant axial and reversed shear loads, the most important observations regarding advanced analytical modeling and accurate earthquake response analysis of RC bridge structures can be briefly summarized as follows: (1) The inelastic behavior of reinforced concrete bridge piers is characterized by a variety of complex influencing phenomena directly resulting from the successive degradation of the steel and concrete mechanical properties, representing their specific inelastic response characteristics and consequently resulting from additionally induced complex time dependent interactive loading effects. For a realistic analytical simulation of such complex nonlinear process, the effects of the most important influencing factors should be estimated and analytically represented. This can be achieved through development of the advanced refined (micro) analytical model and corresponding analytical procedure based on available data from the conducted representative experimental tests. (2) The present experimental results indicate that the inelastic behavior characteristics of the tested RC specimens have been significantly affected by the level of applied axial load, throughout the whole range of imposed displacements. Consequently, it becalmed clear from the tests that the earthquake-induced time-varying axial forces in the critical elements during structural vibration can introduce respective effects to the overall inelastic structural response in a more complex manner. To predict the inelastic earthquake response of specific bridges involving large spans and very tall RC bridge towers, the analytical model should be capable to account for the induced instantaneous interactive effects of bending and time -varying axial forces.
Development of the advanced nonlinear analytical 3D micro-model reflecting to realistically simulate the above stated complex phenomena represent specific study objective of the next planned analytical phase of the present study.