In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state wh...In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.展开更多
The Sutong Yangtze River Bridge(short as Sutong Bridge)is now the largest span cable-stayed bridge in the world.The construction of the superstructure of the middle bridge covered several stages including erection of ...The Sutong Yangtze River Bridge(short as Sutong Bridge)is now the largest span cable-stayed bridge in the world.The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span,assistant span and tower area,erection of standard girders and closure of the middle span.The big block girders were hoisted by a floating crane,and the standard girders were hoisted by a double crane system on the deck.The pushing assistant method was adopted for the middle span closure construction.Furthermore,key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically.An all-stage self-adaptive geometry control method was used in the construction process.By accurately controlling the unstressed dimensions and shape of all structural components in each step,and realization that the control system and the controlled system adapt to each other,the goal was to make control of the final line shape and inner force of the bridge structure achievable.Two solutions,including GPS based and total station based dynamic geometry monitoring systems,were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state.Finally,research on the wind-induced vibration of the superstructure during the construction period was executed.Buffeting response analysis to the longest single and double cantilever states were carried out.The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made,and corresponding wind resistance measures were suggested.The as-built geometric error and cable force error were controlled in a required design range,and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.展开更多
This paper takes the right branch main channel Bridge of Huai River Bridge in Huainan as the engineering background, uses the finite element software Midas and the ANSYS to simulate and analyze the jacking constructio...This paper takes the right branch main channel Bridge of Huai River Bridge in Huainan as the engineering background, uses the finite element software Midas and the ANSYS to simulate and analyze the jacking construction of the bridge, and according to the theoretical calculation, the construction monitoring plan is developed, and the stress and deformation of the key section and part of the structure are monitored. Construction monitoring combined with 3 g network and data acquisition module, monitoring data for the real time measurement, the centralized acquisition and wireless transmission, accomplish on-line real-time monitoring of the bridge construction process, effective control of jacking construction and monitoring. The comparison between theoretical analysis and measured results shows that the simulation results are reasonable, and the construction monitoring scheme based on 3G network and data collection can be used as reference.展开更多
文摘In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.
基金National Science and Technology Support Program of China(No.2006BAG04B03)
文摘The Sutong Yangtze River Bridge(short as Sutong Bridge)is now the largest span cable-stayed bridge in the world.The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span,assistant span and tower area,erection of standard girders and closure of the middle span.The big block girders were hoisted by a floating crane,and the standard girders were hoisted by a double crane system on the deck.The pushing assistant method was adopted for the middle span closure construction.Furthermore,key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically.An all-stage self-adaptive geometry control method was used in the construction process.By accurately controlling the unstressed dimensions and shape of all structural components in each step,and realization that the control system and the controlled system adapt to each other,the goal was to make control of the final line shape and inner force of the bridge structure achievable.Two solutions,including GPS based and total station based dynamic geometry monitoring systems,were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state.Finally,research on the wind-induced vibration of the superstructure during the construction period was executed.Buffeting response analysis to the longest single and double cantilever states were carried out.The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made,and corresponding wind resistance measures were suggested.The as-built geometric error and cable force error were controlled in a required design range,and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.
文摘This paper takes the right branch main channel Bridge of Huai River Bridge in Huainan as the engineering background, uses the finite element software Midas and the ANSYS to simulate and analyze the jacking construction of the bridge, and according to the theoretical calculation, the construction monitoring plan is developed, and the stress and deformation of the key section and part of the structure are monitored. Construction monitoring combined with 3 g network and data acquisition module, monitoring data for the real time measurement, the centralized acquisition and wireless transmission, accomplish on-line real-time monitoring of the bridge construction process, effective control of jacking construction and monitoring. The comparison between theoretical analysis and measured results shows that the simulation results are reasonable, and the construction monitoring scheme based on 3G network and data collection can be used as reference.
