A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate...A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.展开更多
The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for dete...The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for determining the ultimate strength of CFST structures. The accuracy of this method and the applicability of the stress-strain relationships were validated by comparing different existing confined concrete uniaxial constitutive relationships and experimental results. Comparison of these results indicated that this method using the confined concrete uniaxial stress-strain relationships can be used to calculate the ultimate strength and CFST behavior with satisfactory accuracy. The calculation results are stable and seldom affected by concrete con-stitutive relationships. The method is therefore valuable in the practice of engineering design. Finally, the ultimate strength of an arch bridge with span of 330 m was investigated by the proposed method and the nonlinear behavior was discussed.展开更多
A composite shear wall concept based on concrete filled steel tube （CFST） columns and steel plate （SP） deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipat...A composite shear wall concept based on concrete filled steel tube （CFST） columns and steel plate （SP） deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipation elements： CFST columns; SP deep beams; and reinforced concrete （RC） strips. The RC strips are intended to allow the core structural elements - the CFST columns and SP deep beams - to work as a single structure to consume energy. Six specimens of different configurations were tested under cyclic loading. The resulting data are analyzed herein. In addition, numerical simulations of the stress and damage processes for each specimen were carried out, and simulations were completed for a range of location and span-height ratio variations for the SP beams. The simulations show good agreement with the test results. The core structure exhibits a ductile yielding mechanism characteristic of strong column-weak beam structures, hysteretic curves are plump and the composite shear wall exhibits several seismic defense lines. The deformation of the shear wall specimens with encased CFST column and SP deep beam design appears to be closer to that of entire shear walls. Establishing optimal design parameters for the configuration of SP deep beams is pivotal to the best seismic behavior of the wall. The new composite shear wall is therefore suitable for use in the seismic design of building structures.展开更多
The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element mo...The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element model was developed. The out-of-plane equivalent length coefficients of solid-rib arches were obtained using out-of-plane elastic eigenvalue buckling analysis. Then the out-ofplane elastic stability coefficient was plotted against the normalized slenderness ratio,and the out-of-plane eigenvalue buckling load or elastic buckling capability of arches was calculated. Lastly effects of different parameters on the out-of-plane ultimate load-carrying capacity of CFST solid-rib arches were determined using geometric and material nonlinear finite element analysis, and a simplified algorithm was established by fitting the out-of-plane elastic-plastic stability coefficient and normalized slenderness ratio using PerryRobertson formula. Ratio of the elastic stability coefficient to the elastic-plastic counterpart was plotted against the out-of-plane normalized slenderness ratio,from which the out-of-plane elasticplastic ultimate load-carrying capacity was determined according to the corresponding elastic buckling load. Results show that the proposed simplified algorithm can accurately predict the out-of-plane eigenvalue buckling load and the elastic-plastic ultimate loadcarrying capacity of the CFST solid-rib arches.展开更多
文摘A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.
文摘The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for determining the ultimate strength of CFST structures. The accuracy of this method and the applicability of the stress-strain relationships were validated by comparing different existing confined concrete uniaxial constitutive relationships and experimental results. Comparison of these results indicated that this method using the confined concrete uniaxial stress-strain relationships can be used to calculate the ultimate strength and CFST behavior with satisfactory accuracy. The calculation results are stable and seldom affected by concrete con-stitutive relationships. The method is therefore valuable in the practice of engineering design. Finally, the ultimate strength of an arch bridge with span of 330 m was investigated by the proposed method and the nonlinear behavior was discussed.
基金National Natural Science Foundation of China under Grant No.51148009National Natural Science Foundation of China under Grant No.50978005Project High-level Personnel in Beijing under Grant No.PHR20100502
文摘A composite shear wall concept based on concrete filled steel tube （CFST） columns and steel plate （SP） deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipation elements： CFST columns; SP deep beams; and reinforced concrete （RC） strips. The RC strips are intended to allow the core structural elements - the CFST columns and SP deep beams - to work as a single structure to consume energy. Six specimens of different configurations were tested under cyclic loading. The resulting data are analyzed herein. In addition, numerical simulations of the stress and damage processes for each specimen were carried out, and simulations were completed for a range of location and span-height ratio variations for the SP beams. The simulations show good agreement with the test results. The core structure exhibits a ductile yielding mechanism characteristic of strong column-weak beam structures, hysteretic curves are plump and the composite shear wall exhibits several seismic defense lines. The deformation of the shear wall specimens with encased CFST column and SP deep beam design appears to be closer to that of entire shear walls. Establishing optimal design parameters for the configuration of SP deep beams is pivotal to the best seismic behavior of the wall. The new composite shear wall is therefore suitable for use in the seismic design of building structures.
基金National Natural Science Foundation of China(No.51178119)
文摘The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element model was developed. The out-of-plane equivalent length coefficients of solid-rib arches were obtained using out-of-plane elastic eigenvalue buckling analysis. Then the out-ofplane elastic stability coefficient was plotted against the normalized slenderness ratio,and the out-of-plane eigenvalue buckling load or elastic buckling capability of arches was calculated. Lastly effects of different parameters on the out-of-plane ultimate load-carrying capacity of CFST solid-rib arches were determined using geometric and material nonlinear finite element analysis, and a simplified algorithm was established by fitting the out-of-plane elastic-plastic stability coefficient and normalized slenderness ratio using PerryRobertson formula. Ratio of the elastic stability coefficient to the elastic-plastic counterpart was plotted against the out-of-plane normalized slenderness ratio,from which the out-of-plane elasticplastic ultimate load-carrying capacity was determined according to the corresponding elastic buckling load. Results show that the proposed simplified algorithm can accurately predict the out-of-plane eigenvalue buckling load and the elastic-plastic ultimate loadcarrying capacity of the CFST solid-rib arches.
