中小跨径桥梁挠度监测数据的分析与应用

Analysis and Application of Displacement Monitoring Data for Small and Middle Span Bridges

为挖掘中小跨径桥梁挠度监测数据的价值,研究了桥梁挠度监测数据的处理方法,提出了基于挠度监测数据的桥梁性能评价流程,并在一座装配式预应力T梁桥的监测项目中进行了应用。结果表明,监测周期内T梁最大挠度远小于荷载试验结果和规范限值;挠度概率分布与对数正态分布吻合较好,以荷载试验结果作为抗力标准的桥梁刚度可靠度指标大于3.0;各T梁实际冲击系数均值高于理论计算值,且呈现从超车道向应急车道方向依次增大的规律,冲击系数的概率分布不拒绝服从于广义极值分布;挠度沿横桥向变化曲线基本呈直线,变化规律与刚性横梁法的理论假定基本吻合;各T梁实际荷载分担系数明显小于理论横向分布系数,桥梁表现出较好的整体性。

In order to mine the values of displacement monitoring data for small and middle span bridges,the evaluation method of bridge performance based on displacement data was studied,and the data processing flow was carried out.Through application of the proposed method for a highway T-beam bridge,the results show that the maximum displacement effect is far less than the load test result and the designed limited value;the lognormal distribution is in good agreement with the displacement results;and the calculated stiffness reliability index is above 3.0 which indicates that the bridge has a high level of stiffness performance.Meanwhile,it is concluded that the means of impact coefficients for each main girder are higher than the theoretical impact coefficient,and has a rule of increasing from the overtaking lane to the direction of the emergency lane.The probability distribution of impact coefficient does not refuse to obey the generalized extreme value distribution.Furthermore,the displacement changing curves along the transverse bridge are basically linear,which is consistent with the theoretical assumption of rigid beam method.The load carrying coefficients for each main girder are less than the theoretical transverse distribution coefficients,and the bridge shows good integrity performance.