Applied Mechanics and Materials Vols. 204-208

Abstract: In the PC composite box-girder with corrugated steel webs, the mechanical properties depend on the performance of shear connector. In this paper, the most commonly used forms of shear connector in PC composite box-girder with corrugated steel webs are introduced. Then method of design and calculation of shear connector is introduced. At last, the engineering design case of shear connector in the South-to-North Water Diversion Bridge is presented.

Abstract: Use the Finite Element Analysis software to numerically simulate the South-to-North Water Diversion Bridge, a prestressed concrete composite box-girder bridge with corrugated steel webs, during the process of cantilever construction. Then research the force condition of the main girder structure during the construction processes. Results indicated that, during each construction process, the bending moment was reasonable, and all sections of the main girder structure were under pressure. The maximum normal stress always appeared around those cross-sections over the main piers, and during the mid-span closure process, the maximum stress appeared around the mid-span segment’s bottom flange.

Abstract: To study the ship collision security of Xiangjiang bridge, this paper base on the risk assessment criteria of the AASHTO guide. First of all, annual frequency of Xiangjiang bridge element collapse is calculated by using the method of AASHTO guide; Furthermore, the safety of the Xiangjiang bridge is evaluated in according to AASHTO Guide. Calculation and analysis results show that Annual frequency of Xiangjiang bridge element collapse is more than annual 0.0001.

Abstract: Taking suspension bridge for example, this paper based on finite element theory and derived the formulas of pre-stressed modal computing theory of the bridge structure. Then to check the correctness of the theory, we calculated a real bridge model. Finally we get a theory to calculate bridge pre-stress modal.

Abstract: Based on the long-term monitoring data of Donghai Bridge, span length changes of the main channel of the bridge was analyzed from the expansion joint displacement data monitored，and the correlation between the span changes and the environmental factors, which are temperature and wind load, was analyzed. Results show that temperature is the main factor influencing the span change, while the correlation between span changes and wind load is weak so can be ignored. The linear regression model established between span changes and the structure effective temperature can be used to estimate the interval of bridge span changes and examine the correctness of the expansion joint data monitored. Moreover, the regressive model of accumulated expansion joints displacement and time history can provide valuable information for design, maintenance and replacement of the expansion joints.

Abstract: Through theoretical calculation, systemic analysis of dynamic performance of the 64m single and double line railway steel truss bridges on the different speed of train loads. Contrast and analysis the main dynamic performance parameters of bridges on the differend speed. In 64m steel truss bridges in Heavy-Haul Coal Line application practice proves that the deflection of the bridge to the speed is insensitive. The vertical acceleration and horizontal acceleration is sensitive to speed. The speed 80km/h is the speed which lead to the maximum vertical acceleration of the single line and double line in light-load condition.

Abstract: Six equivalent linearization methods are summarized and calculation process of applying equivalent linearization method for displacement-based design of bridge engineering is studied. With the evaluation of volume stirrup ratio and safety performance of design structure, six different equivalent linearization methods are used in displacement-based design of bridge columns. The influence of equivalent linearization model and the damping adjust coefficient to seismic design results is studied. Study shows that there are big differences among the seismic design results based on different equivalent linearization methods. Equivalent damping ratio model and the damping adjust coefficient have great influence on seismic design results. Calculation errors of Kowalsky method and Iwan method and Ou method are very small. Calculation error of Kowalsky method is decreasing when displacement ductility factor increases. The calculated result based on the damping adjust coefficient provided by Eurocode8 specification is more close to the real one. Kowalsky method and the damping adjust coefficient of Eurocode8 specification is recommended to be used in displacement-based design of bridge engineering.

Abstract: Finite element method and model test method are not applicable to analyze the mechanism of PBL shear connector group which is large and complex, because modeling is complicated, efficiency is low and calculation is difficult to converge for the finite element method, and the model test cost too much money and time. In order to improve the analysis ability for the PBL group, the gradually expanding substructure method was put forward for the PBL group transmitting axial load according to the simple boundary conditions and the repeated simple structure components. The gradually expanding substructure method was derived based on the load-slip curve of the single PBL shear connector and the force and displacement equations of the steel and concrete components. Compared with finite element method, the gradually expanding substructure method has some advantages such as the equations are easier to understand, the program is easier to perform and the efficiency is higher.

Abstract: Finite element theory was taken to do a research on a through CFST (concrete-filled steel tube) arch bridge and a change rule of the bridge’s natural vibration frequency was found when its suspenders were tensioning. Through three tension schemes, after solving the first fifteen orders of the natural vibration frequency of each condition and drawing the change curve and analyzing the effect of different suspender tension order on the natural vibration frequency, we come to the conclusion: different suspender tension order will have no effect on the natural vibration frequency when the bridge is completed but when it is constructing, which mainly shows that both the first three and eight to thirteen orders of the natural vibration frequency are discrepant; different location of suspenders has different affection degree on the natural vibration frequency of the bridge. The conclusion has reference value for bridge construction.

Abstract: Based on the orthogonal expansion method of stochastic processes, seismic acceleration processes can be represented as a linear combination of deterministic functions modulated by a set of mutually independent random variables. In conjunction with the probability density evolution method, the random seismic response of bridge structures can be successfully researched. A long-span bridge structure is taken as an example. The probabilistic information of the response of a long-span bridge structure in different control under earthquake excitations is investigated. The investigation provides a new approach to the random seismic response analysis of long-span bridge structures.