体外预应力加固连续刚构桥受力性能分析

THE EFFECT ANALYSIS OF THE EXTERNALLY PRESTRESSED TECHNIQUE IN LARGE SPAN CONTINUOUS RIGID FRAME BRIDGE

本文以三股线5跨连续刚构桥为工程背景,对体外预应力加固方法进行了研究。利用桥梁博士Dr.Bridge 3.0建立该桥的有限元计算模型,通过验算加固前后承载能力极限状态的极限抗力和正常使用极限状态的极限抗力及抗裂,最后在理论计算的基础上进行该桥梁的荷载试验。试验表明:加固后跨中挠度降低23.7mm,合拢段顶板应变降低97.5με,底板应变降低62.5με且挠度及应力校验系数均在理论范围内,说明桥梁加固后刚度和应力状况得到明显改善,加固方案达到预期效果。

According to the background of five span continuous rigid frame bridge in Sanguxian, the method of external pre - stressing reinforcement is studied in this paper. Using Dr. Bridge 3.0 to estab- lish finite element model of the Bridge, the ultimate resistance of ultimate bearing capacity and the ulti- mate resistance, crack resistance in serviceability limit state were checked before reinforcement after, and finally the load test of the bridge is carried out on the basis of theoretical calculation. The results show that the mid - span deflection was reduced by 23.7mm after reinforcement, the strain of the closing roof was reduced by 97.5 με, the bottom plate strain decreased by 62.5 με and the biggest deflection and stress calibration coefficients within the scope of the theory, the bridge reinforcement rigidity and stress state are obviously improved after reinforcement scheme to achieve the desired effect.