Prestressed concrete box girders with corrugated steel webs are drawing much attention as a new type of composite bridge structures in Japan. One of the most remarkable structural characteristics of this construction is the separation of the structural functions among the component members. The concrete slabs resist the bending momentand the corrugated steel webs resist the vertical shearing force. In the present Japanese design codes, the comgated steel webs are designed based on this consideration. In this study, an analytical method to evaluate the distribution of shearing force between the corrugated steel web and the concrete flanges is proposed for a practical and economical design of the corrugated steel webs.
This study is planed to clarify the inelastic behavior and the failure characteristics of the web bolted beam joints. A method for determination of the slip moment and the plastic moment of the web bolted beam joints is described. And then, to examine the bending characteristics of this joints, the monotonic loading tests were conducted on six full scale simple beams having a web bolted beam joint. The test parameters are the arrangement of the web bolts, the magnitude of the hole clearance and the thickness of the web plate. The slip strength, the yield strength, the ultimate strength and the failure mode in the joint behavior are discussed.
This paper presents an investigation of the experimental studies on structural behaviors of connections, especially through diaphragm connection and connection panel, with eccentricity between steel beam and concrete-filled square tubular steel column subjected to incremental cyclic reversal loading. Four subassemblage specimens were tested with experimental variables of eccentricity, thickness of tube and connection type. The estimation methods for the strengths of through diaphragm connection and connection panel are proposed.
This paper presents a method of evaluating the yield strength of square hollow section column to H shaped beam connections stiffened by exterior diaphragms. The full plastic strength is obtained by applying limit analysis to the collapse mechanism, which consists of the yield lines on the column wall and the some yield zones of the diaphragm. The yield strength is derived from the yield areas of diaphragms on the mechanism. The analytical results are verified through comparison with results of finite element analyses and experiments. Further, a practical formula for evaluating the yield strength of the connections is proposed.
Cyclic loading tests were carried out to investigate effects of cross sectional shapes of column geometry and weld condition on plastic rotation capacity of H-beam. To investigate the effect of column geometry, connection sub-assemblage with SHS column, H shaped column and CHS column are tested. Plastic deformation capacity of a specimen with H shaped column was superior to any other specimens. In the case of the specimen with large fusion of throat thickness direction of beam flange or with larger strength of weld than that of beam flange, the plastic deformation capacity was improved.
Bolting-Stop-Hole Method is one of the useful methods to repair the fatigue crack in welded steel structures such as steel bridges. In this method, the stress concentration is reduced by drilling the hole at the tip of crack and tightening the hole by high strength bolt, and the fatigue strength consequently is improved. In this study, for the purpose of making clear repair effects of the Bolting-Stop-Hole Method against fatigue cracked out-of plate gusset welded joints under in-plane bending stresses, stress analyses using three dimensional finite element method, stress measuring tests and fatigue tests were performed on the girder specimen with out-of-plate gusset welded joints. On the basis of analytical and experimental results, the evaluation formula for the fatigue strength has been proposed and its validity has been confirmed.
A semi-closed section is formed by attaching bottom plates of composite slabs to U-shaped steel girders under erection of a composite box girder bridge. In order to predict deformation in this structure system, it is necessary to evaluate the additional stiffness of the plates given to the girders. However, the present situation is that detailed examination is not performed since there is no commercial based software for analysis. The purposes of this study are to evaluate the stiffening effect of the bottom plates of composite slabs precisely and to propose the method for predicting deformation under erection of U-shared steel orders with sufficient accuracy in a short time.
In this paper, the energy absorption performance of a steel bellows as one of the energy absorbing bridge girder connectors is examined by model experiments paying attention to not only the longitudinal but also transverse direction. The brittle fracture of the steel bellows is also investigated by an extremely low cycle fatigue test. The effectiveness of the steel bellows on the seismic behavior of a numerical model consisting of a three-span girder bridge is investigated by a non-linear time-history analysis. It is confirmed that the steel bellows possess the large energy absorption performance, and the displacements of the superstructure and bridge piers can be reduced substantially by using the steel bellows in both the longitudinal and transverse directions.
A rapid construction method of overpasses has been proposed, which features on-site joint between one foundation steel pile and one steel pier in short time. The joint utilizes steel-concrete composite connection to absorb placement error of piling without making concrete footing. Static loading tests were carried out in order to investigate the failure mechanism and the ultimate strength of the connection. Performance of the connection was examined by changing such details as shear connector, filled-concrete, and so on. As a result, it was confirmed that the shear connector was not required in steel shell of the composite connection and that the ultimate strength of the connection was enough for practical application.