Research On Ultimate Bearing Capacity Of Reinforced Concrete Members With T-Section Under Compression Bending,Shearing And Torsion

In the actual bridge engineering,especially the long-span bridge structure with complex system,the stress of its members is often in the multiple compound action of bending moment,torque,shear force and axial force.As one of the most widely used members in bridge engineering,there are few studies on the mechanical behavior of T-shaped RC member under the combined action of bending,shear and torsion.Therefore,the research on the bearing capacity of T-shaped RC member under the combined action of compression bending,shear and torsion is of great significance for enriching the theory of reinforced concrete structures and improving the design level of bridge engineering structures.For T-shaped RC member,the calculation method of bearing capacity under composite load and the flexural performance under different sensitivity parameters are discussed.The main research contents include the following aspects:(1)Based on the orthogonal test design theory and through the finite element numerical simulation,the change rules of the flexural capacity of T-shaped RC member under different axial compression ratio,torsion and bending ratio and reinforcement ratio are studied.(2)The provisions of Chinese,American and European codes on the calculation of composite bearing capacity of RC members are introduced,and the deficiencies are discussed.(3)On the basis of numerical simulation,the mathematical analysis software Matlab was used to conduct regression analysis on the ultimate bending moment data of components under different working conditions,and a practical formula for calculating the bending ultimate bearing moment of t-shaped components under the combined action of bending,bending,shear and torsion was proposed.(4)The experimental study of the flexural behavior for T-shaped RC members under different load group has been conducted with twelve T-shaped RC members,the stress distribution law,ultimate bearing capacity,failure mode,loadstrain curve and load-displacement curve of each specimen in the loading process were introduced in detail.The test results,the results of numerical simulation and the bearing capacity formula of calculation are compared,the bearing capacity of the verification results show that the presented practical calculation formula has good precision.