李忠献, 陈锋. 简支梁桥与多跨连续梁桥上移动荷载的识别与参数分析[J]. 工程力学, 2006, 23(12): 91-99.
引用本文: 李忠献, 陈锋. 简支梁桥与多跨连续梁桥上移动荷载的识别与参数分析[J]. 工程力学, 2006, 23(12): 91-99.
LI Zhong-Xian, CHEN Feng. IDENTIFICATION AND PARAMETRIC ANALYSIS OF MOVING LOADS ON SIMPLY SUPPORTED AND MULTI-SPAN CONTINUOUS BRIDGES[J]. Engineering Mechanics, 2006, 23(12): 91-99.
Citation: LI Zhong-Xian, CHEN Feng. IDENTIFICATION AND PARAMETRIC ANALYSIS OF MOVING LOADS ON SIMPLY SUPPORTED AND MULTI-SPAN CONTINUOUS BRIDGES[J]. Engineering Mechanics, 2006, 23(12): 91-99.

简支梁桥与多跨连续梁桥上移动荷载的识别与参数分析

IDENTIFICATION AND PARAMETRIC ANALYSIS OF MOVING LOADS ON SIMPLY SUPPORTED AND MULTI-SPAN CONTINUOUS BRIDGES

  • 摘要: 移动车辆荷载反复作用会导致桥梁疲劳损伤甚至破坏,移动荷载识别是桥梁健康监测的重要措施之一。采用样条函数逼近法对简支梁桥与多跨连续梁桥上的移动荷载进行识别和参数分析。基于模态叠加法和梁固有振动的精确解,建立了移动荷载作用下简支梁和连续梁的运动方程;利用样条最小二乘法逼近桥梁应变响应,由样条数值微分求得响应导数;再通过Tikhonov正则化方法结合奇异值分解技术得到了荷载识别的正则解。对一简支梁和一三跨连续梁进行了数值仿真,并对一些影响因素进行了参数分析。利用已有的试验数据验证了方法的可靠性。结果表明,样条函数逼近法能有效地识别简支梁与连续梁桥上的移动荷载,具有很强的实用性和抗噪性能;而且简支梁桥上的荷载识别精度和抗噪性能高于连续梁桥;利用Tikhonov正则化方法可得到荷载识别的稳定解,并有利于提高识别精度,降低对噪声的敏感性。

     

    Abstract: Moving loads identification is one of the important measures for health monitoring of bridge because the cyclic action of moving loads may lead to fatigue damage or even failure of the bridge. The identification and parametric analysis of moving loads on simply supported and multi-span continuous girder bridges are performed using the spline approximation method. Based on the modal superposition method and the exact solution of beam nature vibration, the motion equations of the simply supported and continuous girders subjected to a set of moving loads are established. Bridge strain responses are approached through spline least-squares method, and their derivatives are obtained by means of spline numerical differentiation. Then the regularized solution is obtained using Tikhonov regularization and singular values decomposition. The simulation analysis is carried out for a simply supported and a 3-span continuous girders, and the parametric analysis for some influence factors are completed. Some former experimental data are also used to verify the reliability of this method. The results show moving loads on both simply supported and multi-span continuous girder bridges may be identified effectively using the spline approximation method, in which more powerful practicability and noise-proof performance arepresented. The identification accuracy and the noise-proof performance of moving loads on simply supported girder bridge is higher than those on continuous girder. Stable solutions of moving loads may be obtained through Tikhonov regularization, which may increase the identification accuracy and reduce the sensitivity on measuring noise.

     

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