某V形刚构-挂梁组合体系桥梁载荷试验分析

Load Test Analysis of a V-shaped Rigid Frame and Hanging Beam Composite System Bridge

摘要:

为验证某3跨V形刚构+挂梁组合体系桥梁的设计科学性，支撑交工验收及积累养护资料，开展了静动载试验研究。首先采用MIDAS Civil NX建立梁格模型，并通过MIDAS FEA NX构建实体模型进行校核，以城-A级荷载为标准，结合4类针对性工况的3轴载重车辆加载方案，完成了静动力数值模拟，实测了主梁关键截面的变形、应力应变、动挠度和自振频率等核心指标。静荷试验结果表明：静应变和静挠度校验系数为0.54~0.72，相对残余比均不大于20%，无明显可见损伤；动载试验结果表明：实测自振基频为理论值的1.7倍，冲击系数低于理论值，阻尼比符合混凝土桥梁正常范围。整体试验结果表明：该桥梁结构强度与刚度均满足城-A级设计荷载要求，整体工作性能良好，其结构形式可为同类大跨度高刚度桥梁提供参考，且试验数据补充了该类桥梁的行业数据库。

Abstract:

To validate the design rationality of a three-span V-type rigid frame + hanging beam composite system bridge, the static and dynamic load tests are conducted to support acceptance and maintenance data collection. The process begins with establishing a beam grid model using MIDAS Civil NX, followed by verification through a solid model in Midas/FEA NX. Using Class-A load standards and four targeted scenarios with three-axle heavy-duty vehicle loading schemes, the static-dynamic numerical simulation is conducted. The loading tests measure key parameters including deformation, stress-strain, dynamic deflection, and natural frequency at critical cross-sections of the main beam. That static load tests demonstrated: calibration coefficients for static strain and deflection ranging from 0.54 to 0.72, with relative residual ratios below 20% and no visible damage. Dynamic load tests show that: the natural frequency is 1.7 times the theoretical value, impact coefficients below theoretical thresholds, and damping ratios within normal concrete bridge ranges. The overall test results indicate: The bridge's structural strength and stiffness fully meet Class A urban design load requirements, demonstrating excellent overall performance. This structural configuration provides valuable reference for similar large-span high-stiffness bridges, while experimental data enriches the industry database for such bridge types.