The Ultimate Bearing Capacity Analysis of P.C. Bridge Based on Material Performance Degradation

Abstract

During the service process of a P.C. bridge, the mechanical properties of materials (including concrete and steel) will deteriorate, and eventually result in the decrease of ultimate bearing capacity. Considering it’s structural behavior, degenerate solid elements were used to set up a three-dimensional model. By taking prestressed reinforcement as a part of structure, the equivalent nodal load was provided to calculate the effect of tensioning bars. The T.L. method was adopted to consider the geometric nonlinear effect. The Ohtani & Chen model was used to simulate the concrete material nonlinear behavior, and for prestressed steel strand and common reinforced, linear hardening and ideal elastoplastic model were adopted respectively. A P.C. continuous rigid frame bridge was employed for the case study, on the basis of material performance deterioration, the ultimate bearing capacity analysis of P.C. bridge structure was carried out. The results show that material deterioration has great impact on ultimate load capacity of structure: the load factor on limit state dropped rapidly from 13.9085 at t=0a to 7.8265 at t=100a, the corresponding safe index decreased from 2.265 to 1.581, and brittle characteristics was aggravated at the same time.

Evaluation of the Wind‐Resistant Performance of Long‐Span Cable‐Stayed Bridge Using the Monitoring Correlation between the Static Cross Wind and Its Displacement Response

“…e wind-resistant performance of existing bridge structures will inevitably deteriorate due to the influence from synthetic factors, such as concrete carbonation, reinforcement corrosion, and accumulated fatigue damage, which can threaten the entire bridge safety [1][2][3][4][5]. For example, the boundary beam of the SR1014 Bridge in Pennsylvania laterally collapsed mainly due to serious performance deterioration [5].…”

“…erefore, it is meaningful to research the deterioration behavior of bridges throughout their service life, which can help prevent bridge failure. Until now, studies on the theoretical exploration and numerical simulations of the deterioration mechanism have been extensively conducted for concrete bridge structures [1,[6][7][8][9][10][11][12]. For example, Professor Shi chose a simply supported plate girder as a research object and studied the relationship between the material parameters and failure function through a sensitivity analysis [10]; Ye et al researched the performance evolution of one continuous concrete box girder by changing the damage time and damage amount [11]; Tian et al analyzed the performance variation of a continuous concrete girder under chloride penetration environment through finite-element simulation [12]; and Xue et al explored the ultimate bearing capacity of one continuous rigid-frame bridge based on nonlinear simulation of the concrete material [1].…”