基于荷载试验的钢混叠合梁技术评定研究

来源:用户上传      作者:鞠森森　钱若霖　黄春晖　赵春晨

　　摘要：对于现役桥梁的管养小修、对于旧桥的评定加固已成为公路桥梁、市政桥梁建设单位一项举足轻重的工作，本文采用成桥荷载试验研究的评定方法，针对某钢混叠合梁桥梁，通过静载试验研究各主要截面的应力状况、挠度变形，通过环境激励和跑车试验研究桥梁的自振特性和冲击系数。研究表明：该桥的应力和挠度校验系数均小于1.0，表明结构工作状态处于弹性阶段，强度符合设计要求;桥梁基频、阻尼比、冲击系数等动力特性结果均满足规范要求，表明桥梁整体性较强，刚度符合设计要求。基于静动载试验结果，提出了一种置信度优化校验系数区间的方法，有效避免了因数据随机性和离散性过大引起的试验结果精度不足的问题，精确了校验系数的区间范围，给同类桥梁静载试验分析提供一定的借鉴意义。
　　关键词：钢混叠合梁;荷载试验;置信度;区间估计
　　中图分类号：U446.1
　　文献标识码：A文章编号：1001-5922（2022）06-0102-06
　　Research on technical evaluation of steel composite beams based on load test
　　JU Sensen， QIAN Ruolin， HUANG Chunhui， ZHAO Chunchen
　　（Civil Engineering College， Shannxi Polytechnic Institute， Xianyang 712000， Shaanxi China
　　）
　　Abstract：The maintenance and small repair of existing bridges and the assessment and reinforcement of old bridges have become a pivotal task for highway bridges and municipal bridge construction units. This paper adopts the evaluation method of bridge load test research， for a steel-concrete composite beam bridge， the stress conditions and deflection deformation of each main section are studied through static load tests， and the natural vibration characteristics and impact coefficients of the bridge are studied through environmental excitation and sports car tests. Research shows that the bridge’s stress and deflection calibration coefficients are both less than 1.0， indicating that the structural working state is in the elastic stage and the strength meets the design requirements; the fundamental frequency， damping ratio， impact coefficient and other dynamic characteristics of the bridge meet the requirements of the specification， indicating that the rigidity meets design requirements. Based on the static and dynamic load test results， a method for confidence optimization of the calibration coefficient interval is proposed， which effectively avoids the problem of insufficient accuracy of the test results caused by the excessive randomness and dispersion of the data， and precise the interval range of the calibration coefficient， providing a certain reference meaning for the static load test analysis of similar bridges.
　　Key words：steelconcrete composite beam; load test; confidence; interval estimation
　　无论是新建桥梁或是在役桥梁，定期检测和维修是提高其耐久性的重要手段。目前对于桥梁结构构件技术状况及承载能力的评价方法主要有5种[2-4]：外观调查、设计规范方法、专家经验方法、结构可靠性理论方法以及荷载试验方法。据报道，通过5座桥的实际评估结果分析，与规范对比提出了改进建议[5];从标准种类、评定手段、评定过程、病害等级和优缺点等方面入手对多种评定方法进行分析研究并提出了优化建议[6];随机抽取国省干线公路桥梁，分别采用《公路桥涵养护规范》和《公路桥梁技术状况评定标准》对桥梁技术状况进行评定，总结了两种规定下桥梁技术状况评定的特点[7];基于桥梁部位、适应性、刚度退化及病害发展趋势等因素在评定过程中无法合理考虑的问题，优化了桥梁技术状况评定方法[8]。

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