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Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to avoid the instability of arch in thermal environment, the nonlinear in-plane instability of a fixed circular arch under a central radial concentrated load in thermal environment was studied. The nonlinear equilibrium equations and buckling equilibrium equations were derived by the minimum potential principle. The theoretical solutions of the limit buckling and bifurcation buckling loads were then obtained and verified by the ANSYS software finite element results. The nonlinear limit point instability and the bifurcation instability behavior of the arch was investigated. The results show that the temperatures have a significant effect on the nonlinear instability behavior of an arch. The limit instability loads and bifurcation instability loads increase with the rise of the temperature. The upper and lower limit point instability loads decrease with a decrease of the modified slenderness. It is also found that the maximum temperature difference for bifurcation bucking decreases rapidly with the increase of the slenderness. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the concrete-filled steel tube (CFST) supporting structure used in deep-seated soft rock roadway, six equivalent loads are loaded on the 1/4 CFST circular arches. The influence of mechanical properties with different rise-span ratios and steel fiber volume parameters are studied. The experimental results show that the bottom of CFST circular arch is damaged by compressing, bending and shearing. The apex of arch is mainly influenced by compressive stress. Both apex and bottom of the arch are the weakest cross sections. The bearing load and the stiffness of structure are enhanced with the increase in rise-span ratios. The flexibility is increased in test specimen with 1% -1. 5% steel fiber volume parameters while little difference can be found in ultimate load in contrast to the one without steel fiber. With continuing increase in steel fiber volume, the stiffness of specimen is increasing and ultimate load is decreasing. Therefore, 1% -1. 5% volume parameter of the steel fiber is suitable. Besides, by using numerical simulation, the stress forms of the dangerous sections of the specimens and the influence of bearing capacity on the section dimension, rise span ration, wall thickness of steel tubes are further studied. Meanwhile, combined with the experimental analysis and numerical results, theoretical analysis is proposed from three aspects: Section strength, local instability and overall instability. The cause of local instability and calculation formula for the ultimate bearing capacity of circular arch CFST are obtained. Finally, on the basis of practical engineering condition, the design example of CFST is introduced. [ABSTRACT FROM AUTHOR]

This paper presented the out-of-plane elastic buckling behavior of circular steel arches discretely and laterally braced, and based on FE analysis a threshold value of bracing stiffness for design was proposed. The effects of bracing parameters, including bracing stiffness, brace types, the number and longitudinal location of bracing point, on the arch elastic buckling behavior were investigated carefully. An equation for predicting the threshold value of bracing stiffness was obtained for equally-spaced lateral braces of pin-ended and fixed arches with I-section in pure compression. And the required arch segment length between bracing points to prevent the arch segment from elastic out-of-plane buckling was proposed. It shows that, the closer brace is to the crown of arch, the higher efficiency brance has to prevent out-of-plane buckling of arch. When arches with lateral braces buckle, buckling half-waves increase with the augment of bracing stiffness, while arches with torsional braces always buckle with one half-wave. For equally-spaced lateral braces, a threshold value of stiffness of arches in uniform compression is suitable to the arches under other general load conditions. When segment length meets the requirement mentioned above for arches with I-section, in-plane asymmetric buckling form will take place before out-of-plane buckling of arch segment. [ABSTRACT FROM AUTHOR]