The Improving Measures Of The Shear Capacity Of The Specially Shaped Columns Joints

The specially shaped column structure have got broad application in our country dwelling house because of the advantages of improving space utilization; increasing building floorage; lightening the structure weight; raising material utilization and so on. But in high intensity area, its application has been restricted very greatly for its low shear capacity of the beam-column joints. In the abstract, the measures of using steel reinforced concrete specially shaped column; appending armpit under the beam; using high strength concrete or steel fiber concrete replace the normal concrete in the beam-column joints can resolve this problem very well.In actual project, getting a balance between economic effect and structure function is the problem that people cares for most. We can not increase investment or postpone construction or negative build's model only for strengthening the joints, otherwise, using the specially shaped column will become meaningless. For example, using SRC special-shaped column needs increasing investment obviously, and adding steel plates in the special-shaped column whose sections are small commonly is very hard, even can not come true. This is a problem:is it necessary or not to perform this measure only to strengthen the joints.This paper analyzed those measures in construct performance, economic effect and constructing feasibility to draw a conclusion whether those measures are feasible. Then, based on the concrete smeared cracking isotropic constitutive model for concrete, a nonlinear finite element analysis programmer ABAQUS was used. For the analysis of three special-shaped columns in a 6-storey construct which in seismic region with intensity 8 of Chinese intensity scale, got the joints basic's capability which included the load transfer path before and after cracking, stress distribution, crack's occurrence and development and final failure mode of the joints. Contrasted the carrying capacity in specially shaped column joints using high performance concrete and the normal specially shaped column joints. Provided a basis to generalize the measure that using high strength concrete replace the normal concrete in the beam-column joints.