连续刚构桥损伤敏感性分析及改变结构体系加固方法研究

发布时间：2018-06-08 02:13

本文选题：矮塔斜拉体系 + 连续刚构桥　；参考：《山东大学》2017年硕士论文

【摘要】：近几十年来,连续刚构桥在工程中得到了广泛应用,但是,相当数量的刚构桥出现了一个通病"跨中下挠过大"。针对该工程问题,本文对连续刚构桥进行了损伤敏感性分析,进而开展了改变结构体系(矮塔斜拉)加固法的研究。通过有限元分析,研究了超重、预应力钢筋损失、主梁刚度折减、混凝土收缩徐变等敏感性因素,对桥梁挠度及上下缘应力的影响规律,进而通过横向比对分析,筛查出了跨中下挠及主梁开裂的主要影响因素。通过实测数据识别病害桥梁已存应力状态与挠度值,结合影响下挠与开裂的敏感性因素,利用挠度应力拟合法,选定合理的组合工况对桥梁进行损伤模拟。将受损模型依据规范进行应力与挠度验算分析,经验算结果与桥梁病害情况较为一致,并以此修正模型作为后期矮塔斜拉加固的计算依据。参照规范等资料,针对实际桥梁的病害情况,确定了矮塔斜拉加固体系的构造与材料参数,根据合理成桥状态理论,设计了一种切实可行的加固方案。发现了跨中无索区长度与加固效果之间的相关关系,提出了跨中无索区的合理范围。对加固后的桥梁进行了验算分析,结果表明矮塔斜拉体系加固在设计合理的情况下,不仅可以提升主梁,抑制跨中下挠,还可以使主梁的弯矩与应力等恢复到合理状态,使桥梁结构内力得到大幅改善。
[Abstract]:In recent decades, continuous rigid frame bridges have been widely used in engineering. Aiming at the problem of this project, the damage sensitivity analysis of continuous rigid frame bridge is carried out, and the reinforcement method of changing structure system (short tower cable-stayed) is studied. Through the finite element analysis, the sensitivity factors such as overweight, loss of prestressed steel bar, stiffness reduction of main beam, shrinkage and creep of concrete, etc., which affect the deflection of bridge and the stress of upper and lower edge are studied, and then the lateral comparison analysis is carried out. The main influencing factors of midspan deflection and main beam cracking were screened out. Based on the measured data, the existing stress state and deflection value of the damaged bridge are identified. Combined with the sensitive factors affecting the deflection and cracking, the damage simulation of the bridge is carried out under reasonable combined working conditions by using the deflection stress fitting method. The stress and deflection of the damaged model are checked and analyzed according to the code. The result of empirical calculation is consistent with the condition of bridge disease, and the modified model is used as the calculation basis for the reinforcement of cable-stayed tower in the later stage. According to the data of code and so on, the structural and material parameters of the cable-stayed reinforcement system with low tower are determined according to the actual bridge diseases. A feasible reinforcement scheme is designed according to the theory of reasonable bridge state. The correlation between the length of the no-cable zone in the span and the reinforcement effect is found, and the reasonable range of the no-cable area in the span is put forward. The results show that the reinforced cable-stayed system can not only raise the main beam and restrain the mid-span deflection, but also restore the bending moment and stress of the main beam to a reasonable state. The internal force of the bridge structure is greatly improved.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.72

【相似文献】