PC梁加固前后使用性态差异性试验研究

发布时间：2018-12-25 09:33

【摘要】：通过模型梁加固试验,研究桥梁正常使用阶段,主梁开裂前后及加固前后力学性能以及主梁开裂后的加固效果。试验结果表明:在降低主梁应力、挠度和裂缝等关键力学指标上,总体上呈现主被动结合加固法主动加固法被动加固法的规律。在不同等级荷载作用的全过程中,开裂截面的中性轴高度和抗弯刚度随荷载增加均呈非线性变化,以往相关文献中按分段线性考虑不能反映结构真实的截面特性和受力状态变化规律,同时对已经开裂和损伤的旧桥进行加固试验时,计算模型中应考虑运营桥梁损伤的现实状态,否则可能出现部分开裂截面加固后即使在第一级加载作用下,其开裂截面的校验系数(特别是受拉区钢筋应力校验系数)仍不能降低到1.0以内。研究成果可为今后类似工程的加固设计和检测评估,以及有关规范的完善提供参考。
[Abstract]:Through the model beam strengthening test, the mechanical properties of the bridge before and after cracking and before and after the main beam cracking, as well as the strengthening effect of the main beam after cracking, are studied in the normal service stage of the bridge. The experimental results show that, in order to reduce the key mechanical indexes such as stress, deflection and crack of the main beam, the law of active reinforcement method and passive reinforcement method is presented in general. The neutral axis height and flexural stiffness of the cracking section change nonlinear with the increase of load during the whole process of different grade loads. In the previous related literature, the piecewise linear consideration could not reflect the true cross-section characteristics of the structure and the law of the change of the stress state. At the same time, when the old bridge was cracked and damaged, the reinforcement test was carried out. The actual state of damage of the bridge should be considered in the calculation model, otherwise it may occur after the partial crack section is strengthened, even under the first stage loading, The check coefficient of crack section (especially the stress check coefficient of steel bar in tension zone) can not be reduced to 1.0. The research results can be used as a reference for the reinforcement design, testing and evaluation of similar projects in the future, as well as the improvement of relevant codes.
【作者单位】：长安大学公路学院;山西省交通科学研究院桥梁工程防灾减灾山西省重点实验室;山西省交通科学研究院黄土地区公路建设与养护技术交通行业重点实验室;
【基金】：山西省交通厅科技项目(2013-01-06,2016-01-22)
【分类号】：U445.72

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