Advanced Materials Research Vols. 594-597

Abstract: Several methods had been provided to compute bridge collision force among domestic and abroad, the paper took Fujian Saijiang River as a example, and compared ship collision force calculated by different methods and chose the suitable collision force for the collapse of probability calculation. The American AASHTO guidelines and nonlinear finite element were practical to calculate collision force.

Abstract: In order to obtain shrinkage and creep of HPC used in Sutong continuous rigid-frame bridge, shrinkage and creep of plain concrete and RC are investigated under natural environment over two years. Reinforcement ratio 0.76% is close to that of the middle span. Loading stress of creep test is about 15MPa, which is near the maximum stress of the bridge. Four loading ages, 7d, 14d, 21d and 28d, were used to simulate different loading ages in construction. The curves of creep and shrinkage were fitted from test values. The results show the test values of creep and shrinkage were less than the current Chinese bridge code JTG D62-2004, and the creep and shrinkage of RC is less than plain concrete. If the reinforcement ratio is low, reinforcement exerts less influence on creep and shrinkage, and the influence of reinforcement can be neglected in engineering application. Reinforcement can effectively reduce creep and shrinkage if the reinforcement ratio is high.

Abstract: In this thesis, the dynamic responses of simply supported beam bridge in a double-line railway under bidirectional moving loads are mainly studied. To study the characteristics of Euler- Bernoulli beam, a train is simplified as a series of concentrated forces with fixed wheelbase.Structural dynamics is used to deduce the analytical expressions of vertical vibration of simply supported beam under bidirectional moving loads. By simulation software MATLAB, the numerical result of the dynamic responses of simply supported beam bridge could be obtained. Then the 48 meters simply supported beam bridge in a high-speed railway is analyzed, the dynamic responses of simply supported beam of bidirectional moving loads with different interarrival times are discussed.Finally, some general laws for the design of double-line railway bridge are gained.

Abstract: The author took Chuanlingdong Bridge in Fujian Province for example. Applying general FEM software ANSYS and sub modeling technique, 3D model of the whole bridge was built firstly, and then closure section and nearby sections in mid-span were built to sub model. In the sub model, initial mesh was refined, weaken effects of corrugated pipes were considered and plain bars also were built. Based on the fine sub model, original design and construction tolerances are analyzed respectively. At last spatial stresses of closure section were cleared and key influencing factors were concluded. This research showed construction tolerances had a great influence on bursting damage when the design was at a disadvantage.

Abstract: Because of two-way curved arch bridge with low design load, less structural steel, improper construction, overloading and poor integrity, when the bridge structure can’t satisfy the carrying capacity and traffic capacity requirements, we urgently need reinforce the bridge, which has become an important link of safety assessment and insurance of the bridge structures. Internal force calculation of two-way curved arch bridge is done, and calculation conclusions of Aohan Bridge are shown. Plane rod unit’s calculation results show that the bridge under the action of steam-20, hang-100 loads, eccentricity of the section at the arch feet in main arch ring beyond allowable eccentricity, a state of large eccentric's stress appears, and on surface of the arch feet appeared tensile crack in the load simulation. The calculation results of the main arch ring shows that a phenomenon of stress concentration exists in the arch feet, in addition to the influence of big eccentric. Technology processing should be considered when do the arch feet reinforcement. Data from the arch ring calculation results, the bridge has certain overload potential. But according to the bending moment distribution, strengthen the resistance bending moment in the arch feet, an allow full play to the potential of concrete iron in the arch rib under the premise of reinforced the positive bending moment.

Abstract: The mechanical behavior and failure mechanism of stone arch rib enclosed by reinforced concrete under different existed stress state is obtained by the failure test. Normal section bearing capacity effect of different stress states is studied by test results. Then an analytical method considering the influence factors is proposed to count normal section bearing capacity of stone arch rib enclosed by reinforced concrete.

Abstract: In order to improve the design method for resisting crack, this paper analyzed the dynamic characteristics of steel deck asphalt thin surfacing with cracks. The model analysis and harmonic response analysis were included to the steel bridge deck thin surfacing. Impact coefficients were calculated with different load cases, road roughness and crack damage. The conclusions can provide a theoretical reference for the assessments of the dynamic failure and long-term performance of the steel bridge deck thin surfacing.

Abstract: According to pile-soil function and damper boundary condition influence by Finite Element Method, taking Bao-Shu yellow river extra long-span bridge as the project object, the deformation effect of the bridge subjected to flowing and melting ice in spring was analyzed considering static and dynamical action mode. The results revealed that the deformation from this kind of action is tittly small and the bridge structure is reliable and stable. Also the deformation effect of the pier from dynamic ice action is larger than static action. While for two or more piers, the results are reverse.Then the calculation and analysis have been put into design and construction stage.

Abstract: As the bridge design theory and the construction level improving, the requirements on bridge's appearance and coordination of the landscape around have also became higher and higher in the scenic area. In this paper, we conducted a numerical analysis on structure stress of Wudu bridge at Laibao Road, in Fang Shan district , Beijing, located in the Wu du scenic spot. And we seek to provide the necessary theoretical basis for the bridge design and model selection.

Abstract: Assessment system of durability for concrete bridge was built in this paper, and the time variable was introduced in the system. Durability factors in different time were calculated and assessed, then the components and parts of concrete bridge were assessed. Assessment vectors of bridge construction in different time were calculated by combining prediction and assessment of durability. According to the assessment vectors and the asymmetric approach degree method, durability grade of concrete bridge in different time is pre-evaluated.