Analysis And Calculation For Normal Section Bearing Capacity Of Eccentric Tension I-steel Reinforced Concrete Members

Eccentric tension members are very common in practical engineering. Though studies on eccentric tension RC(reinforced concrete) members have been mature enough, studies on eccentric tension SRC(steel-reinforce concrete) members are still need to be done. With the development of forms of architecture and structure of high rise buildings, eccentric tension members have inevitably encountered in practical engineering. However, only the Code for Design of Composite Structure(JGJ138-2012) provides a concrete formula to calculate the normal section bearing capacity of these members. For the lack of test data and also because there is a significant difference between analysis results and test results, it is very necessary to put forward a formula which is more consistent with test results.This paper is based on the 4 eccentric tension beam-and-slab specimens of the Xin Hua Star, and then nonlinear finite element analysis program Open SEES is conducted to analyze the specimens. The results show that, the simulation value is very consistent with the test value. Therefore, it is reliable to analyze the SRC eccentric members using Open SEES. To further verify the reliability, some test results of SRC eccentric compression and bending members are also used, and also get a good result.Based on the reliability, parameter analysis on the influence factors of the normal section capacity of these members with I-shaped steel in them are done. The result shows: the normal section capacity of these members improves with the improvement of the flange area, the thickness and height of the web, the strength of the steel, the area and strength of reinforcement, the strength of concrete, the height and width of the section. And the capacity decreases when the axial tension ratio improves.It is obvious that the formula of code need to be modified after parameter analysis. The method of nonlinear regression analysis is used to get the correction factor based on the relative height and relative area of the flange. The modified formula is clear and safe enough, and compare with the original formula, it is more accurate. Therefore, it can be taken as a reference for design and research.