Advanced Materials Research Vols. 243-249

Abstract: Based on the Navier-Stokes equations which are set up with the arbitrary Lagrange-Euler description, a finite element model considering close fluid-structure interaction (FST) is established to analyze the seismic response of bridge piers in the deep water. The influence of close FSI on the bridge pier is analyzed including the relative displacement, shear force and bending moment. In addition, the close FSI and its effects are discussed with respect to different water levels. The results of the case study indicate that the displacement and internal force will become larger obviously when the FSI is considered. Effects of the close FSI on seismic response of the pier are related to the frequency characteristics of the input earthquake wave. The larger the peak displacement of input earthquake wave, the larger the FSI effects on the displacement response of the pier are and the smaller the FSI effects on the internal force response of the pier. Additionally, the effect of the water level on internal force response of the pier is more remarkable than that on the displacement response of the pier.

Abstract: The analytical theory and computational method for thin-walled curved box girders in terms of the shear lag effect and geometric nonlinearity are presented. Based on the potential variational principle and the theory of thin-walled box girders, the geometry nonlinear governing differential equations of thin-walled curved box girder considering the influence of the shear lag effect of flange’s stress and the large deflection is established. The equation is solved by means of Newton-Raphon iteration method. The results from the present method are in good agreement with those of the test and the segment method. The numerical examples are conducted to verify the accuracy and reliability of the present theories. It is shown that the proposed formulae and method could be referenced to the design for the thin-walled curved box girders considering shear lag effect.

Abstract: As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.

Abstract: The research of optimization for steel truss bridge based on reliability theory is discussed by using optimization and reliability module in ANSYS software. The reliability design method is elucidated by comparing the results of common design with general optimization and reliability optimization.

Abstract: As to sensitivity analysis, based on traditional sensitive factor definition and concept of reliability vector, two kinds of sensitivity problems are putted forward in this paper. And factor sensitivity matrix is defined. As far as large and complex structures are concerned, factor sensitivity matrix of incremental form is given. Furthermore, sensitivity surface is putted forward. ANSYS PDS（ANSYS Probabilistic Design System）can solve the above two kinds of sensitivity problems efficiently. The example bridge is a CFST arch bridge with 83.6 meter-span, which operated for 10 years. The analysis result shows that the definitions enhance the maneuverability of sensitivity analysis, and ANSYS PDS is practical.

Abstract: The main bridge structure of the bridge engineering cross Yitong river, on the 102 national road, is a three-Span flying swallow type special-shaped CSFT arch bridge. This paper introduces the design, process and results of the static model test of the CFST arch bridge.

Abstract: Against the background of a prestressed concrete bridge undergoes fire, the structural properties of the bridge for time being was simulated and analyzed by the GQJS software. The structural parameters were modified according to damage condition of the bridge. The methods will be a valuable reference to analyze similar bridges undergo fire.

Abstract: In this paper, the basic theory of factor analysis and the possibility of its application in the risk analysis of bridge construction was discussed. By making risk questionnaires, the basic data on the factor of bridge construction was summarized. On the basis of statistical processing of the data by SPSS 10.0 software, seven categories of main risk factors were pointed out , which are economy risk, contract and law risk , design risk, construction technique risk ,environment risk ,staff risk and material and equipment risk. Besides, the importance index and the correlation of the risk factors were calculated out. Sequentially, the risk of bridge construction can be evaluated quantitatively.

Abstract: The effect of prestressed degree on seismic performance of prestressed concrete pier is studied. The plastic hinge properties is gotten by means of reinforce bilinear model and concrete Kent—R.Park model. The different plastic hinge hysteresisloops are obtained by setting prestressing tendons and changing prestressed degree. The result indicates that prestressed concrete pier can bear more great ultimate bending moment and more large dissipation energy ability than common concrete pier. Within the ultimate compressive strength, with the increase of prestressed degree, its relative ultimate bending moment of the prestressed concrete pier rises, and dissipation energy ability rises.

Abstract: The effect of Fly ash (FA) and ground granulated blast-furnace slag (GGBS) on sulfuric acid resistance of concrete has been investigated in this study. Cement was replaced by FA with the incorporation amount from 20% to 50% or by GGBS from 35% to 65%. Results indicate that with an increase in fly ash replacement amount, the sulfuric acid resistance of concrete was improved. Sulfuric acid resistance of concrete with GGBS was improved only when the replacement amount of GGBS exceeds 50%. The basic reason for deterioration of concrete in sulfuric acid is the degradation of C-S-H gel in matrix. Increasing the content of SiO₂ in cement paste can improve the acid resistance of concrete.