Advanced Materials Research Vols. 919-921

Abstract: Cable-stayed bridge is main kind of modern large-span bridges. Wind load and vehicle load are main dynamic force on cable stayed-bridge, which can cause large amplitude vibration of cables. In the paper, the nonlinear vibration differential equations of cable with dynamic displacement at its end point in 3D space was derived. The differential equations were analysed by the method of multiple scales and the vibration characteristic was discussed. The differential equations were solved by numerical method. The Trajectory of the cable middle point was plotted. The result of this paper indicated that the vibration amplitude of cable in 3D space is relate to the frequency and amplitude of the dynamic displacement of the cable end point. The results in the paper could be a reference for the research of cable vibration in cable-stayed bridge.

Abstract: Because of dredging waterways, navigable rank of Beijiang Bridge needed to improve to National III level,it was necessary to remove the old Beijiang Bridge, building a new Beijiang Bridge at the same time and the same position. In view of problems as difficult to install launching nose, not enough space to remove beams,stability of the last removed box beam emerging in the process of removing, desiging and installation platform, cutting beams platforms, last-hole assisted platforms,in order to analyse force situation of the guiding beam in the process of push, using finite element software ANSYS to establish launching nose model, by simulating guiding beam at the bottom position by adding reverse force. At last, study guide beams in the up-push limit deviation technology, there was a conclusion: the building of a launching platform, cut beams platforms, last-hole assisted platforms improves the security and the stability of the construction, saves the construction space without damages in the guiding beams, forces conforming to real situation, pushing the limit deviation correction system, ensures box girder deviation in the allowed range. Key technology research in main up-push remove of Beijiang Bridge can be used for other similar bridge engineering.

Abstract: This study was intend to develop the optimal design method of suspension bridge by the reliability analysis based on minimization of life cycle cost (LCC). The reliability analysis was performed considering aleatory uncertainties included in the result of numerical analysis. The optimal design was estimated based on life-cycle cost analysis depending on the result of reliability analysis. As the effect of epistemic uncertainty, the safety index (beta), failure probability (pf) and minimum life cycle cost were random variables. The high-level distributions were generated, from which the critical percentile values were obtained for a conservative bridge design through sensitivity assessment.

Abstract: Mechanical behavior of box girder with corrugated steel webs in completion status of bridge was studied. Based on the cable stayed bridge of box girder with corrugated steel webs on Zhenshui Road in Xinmi City, finite element method (FEM) was applied to calculate and analyze vertical displacement of box girder, shearing stress of corrugated steel webs, normal stress and vertical deflection of concrete plates, longitudinal strain of box girder in completion status of bridge. The results show that vertical shearing stress of corrugated steel webs is approximately uniformly distributed along the height of box girder. Vertical deformations of corrugated steel webs play the dominant role in the whole box girder. Longitudinal strain of corrugated steel webs is smaller than that of concrete plate. Structural design method based on traditional theory that corrugated steel webs bear all the shear force is conservative. Keywords: box girder with corrugated steel webs; cable stayed bridge; deflection; stress; strain

Abstract: The Dissertation, relying on the construction of Zhanjiang Donghai Island Sea-crossing Bridge and adopting the finite element analysis method to calculate the wave force of substructure, proposes the bridge structure analysis method based on dynamic time history of wave loads. Through emulation analysis, structural load effect under waves is attained, making it a theoretically rational foundation for the structure selection and reinforcement of substructure of Donghai Island Bridge and having important theoretical significance and practical value in guaranteeing the bridge security under any seismic sea waves.

Abstract: Risk prevention measures were put forward about vehicle burning in operating periods for three-tower and four-span suspension bridge, combining with the characteristics of bridge vehicle burning accident. The article set up a traffic reporting system of the tankers for a bridge, and determined the report system of tankers across the bridge. Tankers should passed in the middle of the lane near the median under the guidance of bridge manager. Significant indicators were set on both ends of the bridge, so that vehicles could shunt rapidly in extreme fire conditions. Department of public security, fire control, transportation, bridges management center should get together to establish accident emergency rescue leading group, and formulated the security system of fire resistance and rescue organization for YingWuzhou Yangtze river bridge. Video monitoring alarm system and fire control facilities were set up in side pier, side tower, middle of the main span and the middle tower, which provided reliable and prevention measures for bridge operation.

Abstract: Based on the cable stayed bridge on Zhenshui Road in Xinmi City, structure calculation of die carrier and determination of construction pre-camber of its main girder were studied. Using the finite element method, the deformation of die carrier was calculated under the prepressing condition of supporting structure by ANSYS software. Considering the main influence factors, the calculated construction pre-camber was obtained and the construction pre-camber was determined. The comparison between the calculated camber and the actual measured camber of main girder was accomplished. It showed that the error was very small. This study shows that according to the calculated pre-camber, the determination of construction pre-camber is more reasonable. The linear control of main girder can attain excellent engineering effect. It has certain guiding significance for designing similar bridge to determinate the construction pre-camber of main girder.

Abstract: Steel and concrete composite slab is a new type of bridge deck, which is consist of steel plate and concrete slab connected by shear connectors such as perfobond ribs ( usually abbreviated as PBL), studs and so on. Static experiment about four pieces of one-way steel and concrete composite slab using PBL was carried, and the whole-process structural behaviors and failure mode were investigated. Based on the spatial beam element model with the degenerated theory, the nonlinear finite element analysis on experimental specimens was executed. Such structural behaviors as concrete cracking, yield of steel plate, crushing of concrete, and so on are simulated, and are compared with the experimental results. It can be observed that excellent agreements are achieved between experimental results and numerical simulation.

Abstract: Because the flow of river bridge was not suitable for bearing existing vehicle load, it is needed to be dismantled, and a new bridge will build on the original site. The overall construction plan is using double bridge girder erection machines to remove box girder and the suspended beam of the main bridge. In order to guarantee the security of assembling the bridge girder erection machines and lifting the beam, we did some research in assembling technology, using the finite element software MIDAS to establish model of sling equipment, and analyses whether the sling equipment can bear the design load . With the purpose of ensuring the stability and safety of the suspended beam in the process of hoisting, the suitable order of hoisting suspended beam and risk control of slipping the suspended beam were analyzed. For purpose of guaranteeing the stability of the hoisting box girder, the construction team designed the stabilization system. Due to the complexity of the stress of the girder in the demolition process, we use the finite element software ANSYS to establish the model of e box girder in the process of hoisting, and analyze its stress and deformation. According to the practical engineering, we draw a conclusion: the box girder, suspended beam remained stable in the process of hoisting, and their internal forces conform to the requirements of the specification. The overall construction plan can provide a reference for other similar projects.

Abstract: The bridge incremental launching method has been widely used in China nowadays. As one of the key parts in the incremental launching process, traditional calculation methods cannot meet the current accurate demand of stress state for slide beam. With the assistance of finite element software ANSYS and harmonic superposition method, this paper respectively analyzes the local stress state and the overall buckling of roof, web as well as diaphragm of the slide beam by adding the roughness influence of girder undersurface.