钢筋混凝土桥梁抗力模型的建立及应用

Establishment and application of resistance decay model for reinforced concrete bridge

对在役钢筋混凝土桥梁进行可靠度评估和寿命预测中,抗力是可靠度计算的重要因素,建立抗力模型至关重要。针对建立在役钢筋混凝土桥梁抗力模型的这一问题,分析了混凝土强度变化、钢筋锈蚀、混凝土与钢筋的粘结能力变化3大因素及其时变规律。考虑了锈蚀引起的钢筋力学性能降低,引入了基于纤维模型的计算模式不定性参数,采用数学方法建立了钢筋混凝土桥梁抗力随时间衰减模型。引入某钢筋混凝土简支T梁桥进行了抗力模型的计算,验证了模型的可靠性。抗力衰减模型的建立为结构可靠性评估打下了基础。

In the reliability assessment and life prediction of existing reinforced concrete bridge in serv-ice, the resistance is an important factor for reliability calculation .So it is very important to establish re-sistance model .Aimed at the problem of building the resistance decay model of reinforced concrete bridge, the paper analyzed three factors such as concrete strength change , steel bar corrosion and the change of bond capability between concrete and steel bar and their time varying regularity .Considering the decay of steel bar mechanics property caused by corrosion was considered , it introduced the computa-tional model of uncertainty parameter based on fiber model .The resistance decay model of reinforced con-crete bridge was built by mathematical method .The paper introduced a simple bridge of existing rein-forced concrete to calculate the resistance model , and verified the reliability of the model .The building of resistance decay model can lay the foundation for the reliability assessment of bridge .