基于结构检算方法的梁式桥梁结构快速安全性综合评估系统

摘要

In order to solve the problems of the traditional bridge structure bearing capacity evaluation method, a rapid safety-assessment method was established to evaluate the working condition of pre-stressed simple-supporting hollow bridge. Firstly, based on the theory recommended by the national bridge codes, a load-simulating system was developed instead of static loading tests, on which the bridge structure bearing capacity and stiffness calculation system was set up. Secondly, through the field inspec⁃tion and detection means, some technical information about the current staus of bridge structure bearing capacity was obtained, which determine the technical parameters of the calculation system and develop appropriate analysis system to satisfy the actual bearing capacity of the bridge structure. Finally, combin⁃ing the bearing capacity and stiffness calculation system and the analysis system, a series of evaluation parameters that reflect actual bearing capacity and stiffness of bridge structure were calculated and ob⁃tained, which ultimately realized the rapid safety-assessment of bridge structure. Meanwhile, after com⁃paring with the data earned from the field test, the results show that the computed value is slightly higher than the test value, which takes out a certain degree of conservativeness. Both groups of figures share a similar trend, verifying the reasonability and the accuracy of the supporting theory. The method was then applied to an in-service pre-stressed simple-supporting hollow bridge, and obtained the report that the existing bearing capacity and stiffness of the bridge are less than those of the design. The calculation ex⁃ample successfully proves the bridge can fully meet the requirements of continuing operation.%针对传统桥梁结构承载能力评估存在的不足，建立了梁式桥梁结构安全性的快速综合评估方法。首先，以基于规范理论的桥梁结构检算方法为核心，采用模拟车辆系统替代静载试验，建立现役桥梁结构的承载力和刚度计算系统。其次，使用现场调查、检测手段获取结构承载现状的技术状况信息，确定各计算系统中的技术参数，形成符合桥梁结构实际承载状况的分析检算系统。最后，将分析检算系统和承载力、刚度计算系统相结合，计算得到一系列反映桥梁结构现有承载力和刚度的评估参数，从而实现桥梁结构承载能力的快速评估。通过与实桥荷载试验数据的对比分析表明，采用该方法计算得到的实桥挠度较实测值偏大，偏于保守，并且两者具有相同的趋势，验证了该评估方法的安全性和可靠性。同时，以某现役预应力简支空心板桥为例，实现了该桥的安全性综合评估，结果表明该桥的现有承载力和刚度较设计时折损较少，仍然满足现有承载能力大于设计荷载效应的要求，满足安全运营的需求。