基于静载试验钢桁梁悬索桥承载能力评估分析

Load-Bearing Capacity Evaluation of a Suspension Bridge with Steel Truss Beam Based on Static Load Test

早期修建的小跨径钢桁梁悬索桥大部分已接近设计年限,正确评估其承载能力是桥梁维修、加固和技术改造的基本依据。本文首先简单介绍了桥梁承载能力评估的静载试验方法。同时结合城南大桥的实例,分析了现有桥梁结构存在的主要病害及产生的原因。在充分考虑分析现场检测资料和原有设计荷载等级的基础上,建立了考虑结构损伤的有限元模型,制定了静载试验的加载方案。通过试验结果与修正后有限元模型结果的比较,评估了桥梁结构现有承载能力状况,并针对该桥提出了恢复承载能力的加固措施和建议。

Most of Minisize span suspension bridges with steel truss beam constructed in early age will approach its designed working life. Correctly evaluateing its load-bearing capacity is the basic foundation of maintaining, strengthening and technical reconstruction. First, load-bearing capacity evaluation based on static load test was briefly introduced in this paper. Taking Chengnan bridge as an example, the main existing damages and their causations were summarized and analyzed. Adequately considering the field detection datum and original design load rating, a finite element mode with some damages was established. Then, though analyzing the calculatation results, the scheme of static load test was confirmed. Through comparing the static load test results with the results of upgraded finite element, the load-bearing capacity conditions of existing bridge structure were evaluated. In order to resume its load-bearing capacity, some of strengthening measurements and suggestions were proposed.