Applied Mechanics and Materials Vols. 501-504

Abstract: Nowadays, safety evaluation before bridge opening is increasingly emphasized in China. Bridge inspection is important to guarantee the safe operation of the bridge. In order to comprehensively assess the bearing capability and working conditions of Nanxi bridge of Lechangxia water complex, through static loading test and dynamic loading test, we measured the deformability and mechanical properties of bridge beams with different span-ratios and different forms. Basing on the results of dynamic/static loading test as well as the analysis of structure calculation, we conclude that the bearing capability and working state of the bridge are excellent. The knowledge gained from this study can be used as an evaluation reference in the quality evaluation of the same type of projects.

Abstract: In order to make steel box girder - steel tube arch bridge into the bridge state more reasonable, this paper studies the construction monitoring method regarding the fall girder method adopted to conduct system transformation. Using optimal control theory to determine the fall girder method girder jack-up height, control the line shape and stress of arch and girder and derrick force, and control the Vietnam Da Nang Dragon Bridge construction process. Studies have shown that fall girder method to conduct the system conversion can meet the design requirements, and optimal control method in fall girder method system conversion can obtain good effects. Fall girder method and optimization control method is worth extending to the similar bridge construction and control.

Abstract: Prestressed concrete U-shaped continuous rigid frame bridge is a kind of highway concrete bridge which consists of deck plate, edge beam and side beam and other parts. Based on solid degenerate shell element and with the help of layered shell element to simulate the concrete and steel, the spatial prestressed effect can be implemented. At the same time, the cracking, yielding and crushing performance of concrete nonlinear change can be described through appropriate criteria. Research results have shown that the calculated data are of good stability and convergence compared with using SOLID65 element in ANSYS. Early load of the prestressed steel has a smaller increase in linear stage and a rapid increase in the later nonlinear stage. The results provide a reliable calculation method of the ultimate bearing capacity of the highway U-shaped prestressed concrete structures.

Abstract: In order to investigate the track geometry on a long span steel trussed cable-stayed bridge, in this paper, a plane model is built include suspension cable, pylons, floating system and so on based on FEM to calculate the track geometry under temperature load, wind load and train load. Then evaluate the track geometry from the aspects of line profile and track static geometry size deviation. The result shows that the track geometry indicators like vertical curve radius, gradients and static geometric deviation under temperature load and wind load are better than the indicators under train load. The maximum values of track geometry indicators are all appeared in the bridge piers, mainly because the support stiffness is great different between in the bridge pier and in the mid-span cross-section. It is suggested that the flexibility of piers should be appropriate increased to reduce the support stiffness mutation.

Abstract: The design and construction of the stiffening steel truss bridge is a complex and large-scale professional program. The abstract of the plans and the weaknesses of the view angles to the design sketch will also become limitations to the owners and the decision makers. Based on the project of Baling River Bridge of large stiffening steel truss girders, this study creates a three-dimensional fine model for it via CAD, pre-assembles each parts of the bridge, and checks sections and dockings one to one correspondingly. Data conversion of this model directly generates virtual visualized model. This visualized fine model of Baling River Bridge provides decision makers with a visual analysis platform, which also offers technical guarantee and support for sensible decision makings.

Abstract: The sea-crossing bridge construction takes orders the design idea of maximization, the factorization, the standardization and the assembly, which pile caps and pier shafts of the non-navigable span are prefabricated at the focus of prefabricated. In the paper, the precast solutions are put forward to pile caps and pier shafts of the non-navigable span, and the key technical problems of all kinds of precast solutions are analyzed. On this basis, the optimal pier factory prefabrication is proposed by the comparison of various schemes, which is carried out about advantages and disadvantages of prefabricated matching accuracy control, factory prefabrication, concrete placing, transport in the precast yard, transport style and the impact on follow-up construction.

Abstract: EPS (Expanded Polystyrene) materials have the features of super light, water resistance, anti-ageing, corrosion resistance and well supporting itself .They are now widely used in civil engineering because of their unique features for its unique characteristics. This paper introduces the properties of EPS and the application of EPS in the road and bridge engineering. The correlation analysis showed that The pressure on the foundation can be greatly reduced by the EPS filling embankment in soft foundation, and the settlement and displacement of the EPS embankment are small and its stability is good. The application of EPS in the embankment of a bridge can solve the bumping problems due to differential settlements of road and bridge. EPSs application can reduce differential settlement in the embankment splicing and strengthen intensity in the embankment splicing, which making the new and old expressway as a union in the road-widening project.

Abstract: Because the backfill of highway bridge embankment is not dense enough and the located in the hard and soft transition area, the big settlement that threats the safety of driving usually occurs when influenced by the impact load of high-speed vehicles. According to statistic of investigation of the accidents on certain highway, the difference between settlements in bridge abutment and bridge back is around 32mm to 100mm. This kind of big settlement difference is the main reason for bumping and other problems harming the operation of highway. In this paper we experimentally use horizontal bamboo bars used in the construction of side bridge embankment to deal with the continuous backfill settlement, which is effective. Bar pile to treat the settlement of highway embankment backfill is one of the economical, reliable and effective treatment without constructional occupation of driving lanes.

Abstract: The main bridge of Yunshi Hanjiang River Bridge is a prestressed concrete extradosed bridge with two pylons, a single cable plane and with span arrangement (128+238+128) m. The main girder of the bridge is the concrete continuous triple-cell single box girder of long cantilevers and variable sections, the box girder is 26.5m wide. The cantilever of girder is 5.75m wide as to reduce the self-weight of main girder. In the design, the software Dr.Bridge was used to establish the finite element model for the box girder and to carry out the global calculation of the girder lateral calculation. The software ANSYS was used as well to establish the finite element model for the segments of the main girder and to carry out the analysis of the local stress of the girder. The results of the calculation and analysis indicate that the global structure of the bridge is safe and reliable and the structure can meet the requirements for highway vehicle riding safety and comfort. No significant local stress concentration appears in the main girder, the stress amplitude values of the stay cables are within 30Mpa, and the structure can meet the requirements for durability in the process of service of the bridge. With long cantilever design greatly reduce the self-weight of main girder and saving cost, at the same time make the bridge look lighter and beautiful. The results of the analysis provide a reference for analysis on the shear lag effect and lateral calculation of the concrete continuous triple-cell single box girder of long cantilevers and variable sections.

Abstract: Based on the theories of the method of the finite element and the interaction between beam and rail, the common railway bridge: the continuous girder bridge and the simply supported girder bridge as an example, set up the integration of the calculation model of the line-bridge-pier on the continuous welded railway bridge, through the calculation software of Bridge Continuously Welded Rail (BCWR2010), the regular pattern of the effect of the bending force and the regular pattern of the longitudinal displacement distribution of the rail and bridge are analyzed.