可考虑温致位移时滞的大跨桥梁支座劣化预警技术OA北大核心CSTPCD

To realize the accurate identification of the performance deterioration of long-span bridge bearing,an early warning method of long-span bridge bearing performance deterioration considering the time lag of the thermal-induced displacement was proposed.Firstly,the mechanical behaviors of bearing sliding under the temperature effect was analyzed,and the variation characteristics of the thermal-induced displacement before and after bearing performance degradation were revealed.Secondly,a gated recurrent unit(GRU)network model considering the time lag effect of the thermal-induced displacement was established to predict the bearing thermal-induced displacement.A warning indicator of the thermal-induced displacement prediction residual er-ror(TDPE)that can eliminate the influence of the temperature effect and highlight the performance degrada-tion of the bearing was proposed.Finally,the effectiveness of the proposed method was verified based on the monitoring data of a long-span bridge.The results show that the GRU network model can eliminate adaptively the time lag effect of the bearing thermal-induced displacement.The bearing displacement can be predicted with high accuracy and the prediction error is within 5 mm.The warning indicator of the TDPE can realize the abnormal incremental warning of the bearing thermal-induced displacement more than 4 mm.