城市矮箱梁体外预应力加固设计效果分析

ANALYSIS OF EXTERNAL PRESTRESSED REINFORCEMENT DESIGN EFFECT OF URBAN LOW BOX GIRDER

文中以某城市内的一座单箱多室连续矮箱梁为背景,对桥梁进行外观和材质检测,分析裂缝产生原因,并进行静载试验。根据该桥的竣工图纸建立有限元计算模型,分析桥梁在荷载作用下的应力与变形;然后根据加固设计方案,对比分析再经过施加体外预应力后的桥梁的应力以及变形;经过计算分析表明,经过体外预应力加固后的桥梁截面能有效的增加应力储备和控制截面的变形。加固后的静载试验结果表明桥梁的实测挠度值和实测应变值均小于理论计算值。说明该桥通过体外预应力加固得到了预期的效果,该方法是可行有效的。

Based on a single-box multi-chamber continuous low box girder in a city, thispaper introduces an examinationof the appearance and material property of the bridge. Besidesanalysisofcauses of the cracks and static load tests are conducted. According to the completed drawings of the bridge, the finite element calculation model is established to analyze the stress and deformation of the bridge under load. Then according to the reinforcement design, the stress and deformation of the bridge after external prestressing are compared and analyzed. The analysis result shows that: the stress reserve and deformation control of the section can be increasedeffectivelyafter external prestressing. The static load test results show that the measured deflection value and the measured strain value of the bridge are smaller than the theoretical calculation value after reinforcement. It shows that the external prestressing reinforcement of the bridge is effective. And the method is feasible.