Research On Bearing Capacity Of Reinforced Concrete Short Column Subjected To Biaxial Eccentric Compression

In practical engineering, reinforced concrete columns as purely uniaxial eccentriccompression member is not exist. If we consider the additional eccentricity, basically allof the reinforced concrete columns are biaxial eccentric compression members. For loadbearing capacity calculation of reinforced concrete subjected to biaxial eccentriccompression, we often ignore the moment in one direction, and approximation calculatethe bearing capacity as uniaxial eccentric compression member. But in many cases, therelative eccentricity in two direction is both kind of the same, such as a frame structurecorner column, then we cannot calculate the load bearing capacity as uniaxial eccentriccompression member, but must calculate as biaxial eccentric compression member. Inresearch of load bearing capacity of members subjected to biaxial eccentric compressionat home and abroad, based on destruction curved surface concept proposed by theB.Bresler, the schlars find more convenient and practical design method by simplifyingthe Ni Keqin equation. the simplified design method remains essentially the loadbearing capacity of reinforced concrete subjected to biaxial eccentric compression arecalculated simplified as equivalent to the uniaxial eccentric compression members.Based on the concrete softening properties, reinforced concrete constitutive model,iterative method, nonlinear analysis of reinforced concrete and so on, in the basis ofsection strip method, we establish nonlinear finite element fiber modal analyticalprocedure of reinforced concrete subjected to biaxial eccentric compression byconsidering geometric and material nonlinear, and simulation the load bearing capacityof reinforced concrete subjected to biaxial eccentric compression.By means of nonlinear finite element analysis program of reinforced concretesubjected to biaxial eccentric compression, we conduct a large number of numericalexample to simulate the destruction curved surface of reinforced concrete subjected tobiaxial eccentric compression, and research and analysis eccentricity, the eccentricangle in fluence of the ultimate bearing capacity and section neutral features. Comparethe ultimate load gained by computer program and calculated by formulas and discss thereliability of formulas.Centered on this goal, the following tasks are conducted:①We can conduct test simulation by means of reinforced concrete biaxialeccentric compression members nonlinear finite element analysis program and verifythe simulation results about the ultimate bearing capacity. ②The author simulate the N-Mx-My destruction curved surface of reinforcedconcrete subjected to biaxial eccentric compression through using the computerprogram and analyze eccentricity,the eccentric in fluence of the ultimate capacity.③By the comparative analysis of the ultimate bearing capacity of reinforcedconcrete members subjected to biaxial eccentric compression gained from the computerprogram and formula, we examine accuracy and security of formula in calculating theultimate bearing capacity of reinforced concrete members subjected to biaxial eccentriccompression, make recommendations about formula where is insufficient and give themodified formula.