Applied Mechanics and Materials Vols. 587-589

Abstract: With a bridge which appearing disease cause a insufficient carrying capacity as background, this paper used bridge finite element analysis software combined with field loading test to analyze Prestressed Carbon Fiber Plate reinforcement effect .The results show that the reinforcement method has a remarkable effect in improving the structure stiffness and the natural frequency of vibration , improving the carrying capacity of old bridge and overall security.

Abstract: Skewly supported continuous box girders have special mechanical properties compared with common continuous box girders. Skew coefficient for stress of skewly supported three-span continuous box girder is introduced to reflect the decrease degree of the normal stresses at the cross section of the middle span of the box girder. The finite element models of the skewly supported three-span continuous box girders with different skew angles are established by applying the SHELL63 shell element in software ANSYS. The variation of the skew coefficient for stress at different calculation points of middle span cross section under concentrated load is analyzed and the corresponding influence law is revealed. Research results show that the skew coefficient for stress of top slab is different from that of bottom slab at the cross section of the skewly supported three-span continuous box girder. The skew coefficient for stress of top slab is smaller than that of bottom slab. Skew coefficient for stress decreases with the increasing of the skew angle. Because of the shear lag effect, the minimal skew coefficient for stress of flanges occurs at the free tip of cantilever slab while the maximal skew coefficient occurs at the intersection of web and flange slabs.

Abstract: Loading tests of pedestrian bridge are important procedure for checking the carrying capacity and the construction quality of structures. Static loading test and theoretical analysis of a pedestrian bridge are carried out in this paper. According to a practical engineering, a three-dimensional finite element model of the pedestrian bridge is established using software SAP2000. The strain and vertical deflection of the bridge subjected to the static load are measured and compared with the theoretical value. The verification coefficient and the relative residual deflection under static load are calculated according to the technical specifications. The results show that the actual behavior of the bridge satisfies the requirement of technical specifications and the bridge works well. The static loading test and analysis can provide useful reference for the similar structures.

Abstract: Penang second bridge in Malaysia is designed as a cable-stayed bridge based on British specification. For the requirement of service life of 120 years for this bridge, some measures improving the durability have been proposed in this article. Environmental type and action, condition of raw materials in local, characteristics of elements and requirements of durability indexes for British standard are introduced. Especially, a comparison between British and China’s specification has been made in this article. Mix proportion has been optimized and pulverize fuel ash cement-GGBS-silica fume binder is adopted to prepare mixes for different structure elements. Finally, the measures of durability for Penang second bridge have been set up.

Abstract: HuaRonggou bridge is a continuous beam bridge, which is built recently in Inner Mongolia. In order to test the service behavior of structures, while the bridge is working in the condition of static and dynamic load, and evaluate whether the construction quality is to meet the design requirements, the static and dynamic load test is carried out. This paper describes the principles and methods of the load test, the measurement of the stress and strain, and dynamic characteristics of the bridge structure. By finite element analysis, it can provide the operation and supervision with benchmark data, and also offer the reference to constructions of the same kind of bridge.

Abstract: A large horizontal force will be generated to the pier when the movable die carrier walks to the next span, especially for the high-pier bridges. thus a horizontal deflection will be produced as well as cracks developed. With solid degenerated virtual laminated element program, considering both geometrical and material nonlinearity, the mechanical performance of the pier under a horizontal force on the top of the pier is simulated and illustrated, and the cracks emerged at the bottom part of a high pier in the process of the movable die carrier walking to the next span is analyzed. The results show that when the cracks emerged, the stress of the bars and the stress of the concrete in the compression zone is quite small, hence the safety of the bridges in the construction stage is confirmed.

Abstract: This paper analyzed the seismic response of fabricated box girder bridge considering the traveling wave effect based on ANSYS. Take a multi-connected continuous girder bridge over sea island as the research object, consider the effect of pile-soil interaction, the internal force and deformation characteristics of substructure, coping and expansion joint of the bridge are analyzed under the traveling wave effect. Traveling wave effect have some influence on the internal force and deformation of substructure and coping, but the influence is not so strong. Meanwhile the relative displacement of expansion joint and collision force of beam end are influenced significantly, and the risk of girder falling is increased.

Abstract: This paper is aimed to analytically study the ultimate state of bridges with seismic soil-pile-structure interaction. Since the Vector Form Intrinsic Finite Element method is superior in managing highly nonlinear engineering problems even with fracture and collapse, it is used in this study to predict the failure process of bridges. During an extreme earthquake, soil may undergo plastic behavior, and piles may go through cracking, plastic hinge, even fracture. In this study, several nonlinear soil-spring models are developed to simulate the soil-structure interaction behavior under strong ground motions. Through a series of parametric studies, the failure modes are demonstrated for bridges with pile foundation. The result showed that, both soil and piles went through plastic behavior. It is suggested to analyze bridges under strong ground motions by using nonlinear soil elements for realizing the actual dynamic behavior.

Abstract: A large span steel truss bridge, it assembles "high, big, difficult, new, deep, steep, dangerous, heavy", etc., "eight" features in a body. In order to reduce the number of transportation ships and make the erection convenient, this paper studies a set of revolving beam erection scheme to improve the utilization efficiency of trestle. Through calculation, it is found that fetching girder directly from trestle is feasible. cantilever erection of the girder , The main truss linearis of the steel truss girder upstream and downstream has slightly deviation with the operating angle change of the cantilever crane and it need to stop lifting when monitoring and measuring, and the mast should be placed along the bridge direction.

Abstract: This paper took the Wuhan Erqi Yangtze River Bridge as an example, using MIDAS software to simulate the working procedure of cantilever construction, and established the finite element model of composite girder cable-stayed bridge with three pylons during construction stage. Based on the first kind stability theory, this paper researched the influence of the different construction scheme, the setting of temporary pier, temperature load, and unbalanced construction load on the structure stability of composite girder cable-stayed bridge with three pylons so as to obtain the linear elastic stability safety coefficients of structure during construction stage, and then provided the theoretical explanation to the reasonable construction scheme and safety construction. The results showed that for the Wuhan Erqi Yangtze River Bridge, its linear elastic stability safety coefficients of structure during construction stage have met the code requirement. Besides, the buckling mode changed from the longitudinal buckling of pylon to combined instability of pylon and girder. Furthermore, the setting of temporary pier was reasonable, which effectively improved the linear elastic stability safety coefficients. Finally, temperature load and unbalanced load in construction reduced the linear elastic stability safety coefficients.