桥梁动态称重迭代算法的理论与试验研究

桥梁动态称重(bridge weigh-in-motion,BWIM)能够以桥梁作为载体识别过往车辆的轴重。商用BWIM系统通常基于Moses算法,以桥梁的实测影响线对车桥实测动力响应进行轴重识别。然而,该算法的轴重求解方程是病态方程,在特定情况下轴重识别精度偏低。为解决这一问题,该研究提出桥梁动态称重迭代算法,通过Moses算法和实测影响线算法之间的反复迭代,修正病态的轴重求解方程。该研究介绍了桥梁动态称重迭代算法的原理,并进行了相关公式推导;基于怀化舞水五桥引桥的车桥动力试验,对比分析商用BWIM算法和桥梁动态称重迭代算法的轴重识别精度;并深入探讨影响线的选取对轴重识别精度的影响。研究表明,桥梁动态称重迭代算法能够在一定程度上提高轴重识别的精度,其最佳的基准影响线是实测均值影响线。

Theoretical and experimental study on a bridge weigh-in-motion iterative algorithm

Bridge weigh-in-motion(BWIM)is a method using the bridge as a carrier to identify the axle weights of passing vehicles.The commercial BWIM system utilizes the measured influence line of the bridge to obtain the axle weights based on the Moses’algorithm.In the Moses’algorithm,the equation for resolving the axle weights is an ill-conditioned equation,and the accuracy of the axle weight recognition is rather low under certain circumstances.In view of this,a bridge weigh-in-motion iterative algorithm was proposed,which uses iterations between the Moses’algorithm and the measured influence line algorithm to find the axle weights of vehicles traveling on the bridge.The principle of the bridge weigh-in-motion iterative algorithm introduced,and relevant formulas were deduced.Then,taking the field test data of the approach bridge of Wushui Fifth Bridge in Huaihua city Hunan province as an example,the results of the axle weight identification by the commercial BWIM algorithm and the bridge weigh-in-motion iterative algorithm were compared and analysed.The influence of the selection of the influence line on the accuracy of the axle weight recognition was discussed in depth.The research shows that the proposed bridge weigh-in-motion iterative algorithm can improve the accuracy of axle weight recognition,and the measured mean value influence line is the best choice for finding axle weights.