高强钢筋混凝土连续梁弯矩调幅研究

For the continuous concrete beams with high-strength steel bars as tensile reinforcement, the process from the tensile concrete turning into the plasticity to the steel bars yielding becomes longer due to the increase of the yield strength of the steel bars. In this stage, the proportion of the moment redistribution to the total moment redistribution increases. The plastic hinge appears to be delayed and the plastic hinge rotation capacity decreases when the relative depth of the compression zone is constant. Based on this, the moment redistribution in continuous beams with high-strength steel bars was divided into two stages according to whether the steel bars has yielded or not. 336 continuous beams were parametrically analyzed with the relative depth of the compression zone, yield strength of the steel bars, span-to-depth ratio, loading forms and width of the mid-support as control variables. The results indicate that, the first-stage moment redistribution is increased and the second-stage moment redistribution is decreased with the increase in the yield strength of reinforcement. The two-stage moment redistribution is decreased with the relative depth of compression zone increasing. The first-stage moment redistribution is increased as the width of mid-support increases and the span-to-depth ratio decreases. And the variation of the second-stage moment distribution is not significant with the width of mid-support and the span-to-depth ratio. Formulas of the two-stage moment redistribution in continuous beams with different loading forms are proposed considering the effects of the above-mentioned parameters.