Applied Mechanics and Materials Vols. 90-93

Abstract: This paper introduces the design of a reinforced concrete slant-legged rigid frame bridge built in a county town. The bridge shape and structural project were selected considering factors such as hydrology, environment, art expression and construction technology. The design software MIDAS Civil 2006 was applied to build the numerical model for analyzing the static and dynamic properties of the bridge structure. The results show that the loading performances of the bridge satisfy the specifications of current Chinese design codes. The bridge was constructed and had been operating since Oct. 2008. Now, it becomes a landscape of the county town.

Abstract: The externally pre-stressed steel-box girder bridge is a novel structure, it has the advantage of lightness, less height and fast construction speed. The structure has a very bright application prospect in the future. Seismic effect of this kind of bridge was analyzed with the finite element method in combination of engineering practices. The dynamic characteristics, dynamic response under the action of E1 and E2 was calculated. The results of first five natural frequencies, mode of vibration, internal force and deflection under the action of seismic were listed and discussed. The results show that the externally pre-stressed steel-box girder bridge has a good seismic performance.

Abstract: According to using status of short span concrete bridges commonly used in highway viaduct, structural finite element analysis taking account of some parameters like connection between pier and beam, pier height, transverse bearing spacing and early support differential settlements was given based on existing cracking beams of small box girders during construction and operation. Some structural optimization recommendations and construction control suggestions was proposed. The study results are constant well with the data of the survey results and the actual status of projects, which may be taken as reference for similar projects in the design and construction.

Abstract: The remaining service life of reinforced stone arch bridges is of great concern to management and conservation units. It is also the scientific basis for decision to next reinforced maintenance or rebuild. The concept of time-dependent reliability is introduced. Accoding to the most common section enlargement reinforcement method, the load and resistance of the structures are analyzed. The analysis methods and steps of life prediction are proposed, and the remaining service life is obtained. Based on above methods, an engineering example is given, the service life forecast calculation of reinforced stone arch bridges is discussed.

Abstract: In this paper, the dynamic characteristics of short-span suspension arch bridge are analyzed, and the influence of parameters for constant-load variation, stiffness condition and displacement boundary condition to the dynamic characteristics is studied; the main design parameters of influencing dynamic characteristics of suspension arch bridge are put forward. The study results provide the theoretical basis for the optimization design of suspension arch bridge.

Abstract: The self-anchored arch-suspension bridge is characterized by innovative structure and beautiful shape. In order to research the mechanical characteristics and stability of this structure that has never been built, the proposed preliminary design of the combined system bridge with a main span of 406m is studied. On the basis of the transfer mechanism of live load based on the deflection theories of suspension bridges and arch bridges, the stability of the combined system bridge is analyzed in this paper. The universal finite element software ANSYS is applied to study the linear elastic stability and the geometrically non-linearity stability under six load cases. The study indicates that the transfer mechanism of live load is determined by the distribution of the stiffness. There is no possibility of in-plane instability under live load. The first-order linear elastic instability mode shows the shape of lateral flexure of the junction at mid-span, and the geometrically nonlinear stability is controlled by the lateral flexure. These conclusions can be of some value for the design, calculation and operation management of this structure.

Abstract: The use of high strength reinforcement and high strength concrete in bridge columns is increasing due to many advantages of the high strength materials. In order to study the equivalent plastic hinge length of reinforced concrete bridge columns，37 column test results by using high strength reinforcement and high concrete were collected. Then, the equations proposed by Priestley, Paulay, Telemachos and JTG/T B02-01-2008 to predict the equivalent plastic hinge length of the columns were evaluated based on the experimental results. Influence factors which affect the equivalent plastic hinge length of high strength concrete bridge columns were studied through grey correlation analysis. It is found that, comparing to test results, all the proposed equations show considerable scatter in estimating the plastic hinge length of the high strength bridge columns using high strength reinforcement. The equations proposed by Paulay, Telemachos are not safe, while Priestley and JTG/T B02-01-2008 proposed equations give conservative results. Among the influence factors, the diameter of longitudinal reinforcement is the most important, secondly is the column length and section width. The axial load ratio of the column and transverse reinforcement of the specimens show small influence.

Abstract: In order to study the ultimate load-bearing capacity of the long-span concrete-filled steel tubular (CFST) arch bridge with fly-bird-type, the ANSYS finite element program was used to establish its special model, and to study ultimate load-bearing capacity of this bridge with three different methods. The constitutive relation factors of concrete-filled steel tubular was taken into consideration including confining effect ultimate load coefficients, failure modes, and load-displacement curves of this bridge under different cases. The result indicate that the ultimate load-bearing capacity of the bridge can meet the requirement, all of its failure modes is out-plane, the two methods, linear elastic buckling analysis and only geometric nonlinearity analysis, will over high estimate ultimate load-bearing capacity of this bridge, and linear elastic buckling method cannot reflect real failure mode of this structure. In order to correctly estimate the ultimate load-bearing capacity of the bridge structure, the effect of geometric and material double nonlinearity couldn’t be neglected.

Abstract: Abstract：The paper takes heavy haul train existing slab culvert disease and the research status for starting point, researches and analyzes the reliability assessment of slab culvert and fatigue test under heavy haul train. Different corrosion rate and reinforced section failure probability and reliable probability relations is researched as the emphasis . Strain-stress relations and slab culvert reinforced load are studied by the fatigue test , drawn the fatigue life of tensile steel. The research provides a reference for the stress analysis of slab culvert under the point supported conditions.

Abstract: There is a strong need in maintenance and management of bridge that analyzes and predicts remaining service life (RSL) of reinforced concrete bridge. Since structural resistance of concrete bridge is generally suffered from environment, load and material etc. factors, which are intercoupled and time-varying. Hence researchers should consider the economic development of road traffic area, environment of operational bridge, variation of load, deterioration law of materials, and maintenance cost of LCC for predicting RSL of bridge. This paper reviews recent model of predicting the remaining service life (RSL) for concrete bridge and serviceability, analyzes model characteristic and defects, and looks forward to future research from the viewpoint of structure durability, reliability and life cycle cost, respectively.