The Mode Of Full Life Stresss Monitoring And Safety Appraisal Based On Pre-embedded And Surface Mounting Sensors In Large Bridge

The long-term stress monitoring of large bridges in the operating state has been achieved by two ways including pre-embedded and surface mounting. The pre-embedded approach can resolve the issue of monitoring dead load stress,but the long-term monitoring can not be achieved due to sensor life. The surface mounting sensors have the advantage of being replaced, but they can not solve the issue of monitoring dead load stress. Therefore, when implementing stress monitoring of bridge in the past, the structural stress monitoring of the construction period and operation period was often out of touch and could not be effectively combined,which made the monitoring fail to achieve the desired effect. This issue aims to focus on processing the monitoring data, analyse and conclude the correlation of stress which is monitored by means of pre-embedded sensors and surface mounting sensors,and establish the mode of full life stress monitoring and safety appraisal based on pre-embedded and surface mounting sensors in large bridges.The factors of bridge resistance is analysed,for the bridge component resistance statistical parameters,the amending technology of the resistance statistical parameters in the initial period and operation period of bridges is proposed.The statistical methods and probability models of dead loads, vehicle loads, temperature loads are summaried,the action effect models of which are amended and for which the amendment proposal is presented combined with the monitoring information.The temperature amending method of real-time monitoring data of bridge is researched, the relationship between temperature and monitoring indicators is found based on the statistics regression analysis,then through the deduction of the effect of temperature loads,the characteristical data that can reflect the bridge status is obtained. Integrating bridge construction monitoring and health surveillance systems forms systematic theory and method.The combination of the strain (or stress) sensors which have been embedded within the structure and the surface mounting sensors of bridge forms more accurate and reliable structural safety monitoring system which conducts from construction to operation period of bridges in the whole process and whole life.Finally, analysising monitoring data by application of mathematical statistics theory summarized the correlation of stress which was monitored by means of pre-embedded sensors and surface mounting sensors, then the complementary advantages between the two stress monitoring means are achieved,and the long-term safety monitoring on bridges can be realized. Relying on the Nu River Bridge in Yun nan,the surface mounting sensor layout and safety assessment program considering the life-cycle monitoring are proposed through fully understanding its monitoring system and the analysis on monitoring data of the pre-embedded sensors. The evaluation model which will have wide application prospect and major social and economic benefits integrates knowledge including information, mathematics and mechanics and so on.