Analysis On Seismic Damage And Seismic Performance Of Reinforced Concrete Rectangular Bridge Piers

With the rapid development of China's economic and the prosperous of the livelihood economy, the construction of various types of long-span bridges is in full swing. The construction of large-span bridges are often inseparable from the extensive use of steel and concrete. On the other hand, the seismic activity in our country are extremely frequent,Earthquakes often lead the collapse of lifeline bridge, delay the rescue time, cause a great loss of life, and the seismic fragility of reinforced concrete structures is large, therefore making the depth research on damping theory for the reinforced concrete structure have its full necessity.In previous studies, people tended to ignore the cumulative effect of damage of concrete materials and structures, just only accorded the dynamics theory to calculate and analysis, the results often could not reflect the real situation, especially in the period near the structural failure. If estimating the damage of the structure, considering the cumulative effect of damage and inferring the remainder resistance of structure, it can provide a scientific and rational basis for analyzing the dynamic characteristic of the reinforced concrete structure, assessing the safety of the structure, and for bridge seismic retrofit technologies, post-earthquake reparation and the maintenance of old bridges.This paper detailes the theoretical basis of damage mechanics, analyzes and summarizes the concrete damage model and damage constitutive equations, sums up their respective advantages and limitations. The main contents of this paper include the following five-point.Firstly, the basic concepts of damage mechanics, principles, basic assumptions and damage classify are detailed. the damage phenomena and the damage formation mechanism of concrete material is analyzed. Meanwhile, in order to avoid the shortcomings of Classic Damage Theory, on the basis of the strict Irreversible Thermodynamics Theory, damage evolution equation is detailed and a concrete damage model suitable for common form is obtained.Secondly, some reinforced concrete rectangular bridge piers models are produced to do quasi-static test in the reciprocating load. Some date of rectangular bridge piers from the PEER database in the United States are picked out. Then a part of data for analysis are selected, the parameter of materials are sorted out, the design details, the test process the test loading and the test phenomena of the models are detailed. Analyzed parameters of hysteretic properties and ductility properties under cyclic loading.Thirdly, a solid model of reinforced concrete rectangular bridge pier is established to make the numerical finite-element simulations by using the large finite element analysis software ABAQUS. Then, the material subroutine UMAT is wrote, according to a part ofresults, the damage parameters of models are gotten by shooting methods.Fourthly, through making nonlinear regression analysis on parameters by shooting calculation in the use of statistical analysis software SPSS 19 software, a empirical expression, indicating the relationship between material parameters and impairment parameters, being composed of variables that contain the ratio of axial compression, the shear span ratio the stirrup ratio, the ratio of Longitudinal reinforcement, is fitted out.Fifthly, by using the fitting expression to evaluate and analysis the hysteretic behavior of a set of specimen by the means of numerical simulations, comprising with the hysteretic behavior with the text piece, its rationality is evaluated.