| With the development of national economy, a large number of abnormal joints in R.C. frame structures appear in complex architectural structures. Buy now, most studies of joints focus on normal joints. Now, current design cods for abnormal joints which have different depth beams are mainly based on the general joints'experimental data or designer's experience, and it is lack of perfect theoretical foundation. On the basis of the experiment of 6 abnormal joints of R.C. frame, this paper includes following research:1.The mechanics of shear resistanc of the joints are analyzed detailedly and roundly, and strut model,shear-friction model and truss model are introduced clearly. Based on the analysis of the primary factors which affect the bearing capacity of joints, anti-seismic design of joints in R.C.frame in Code for Design of Concrete Structures(GB50010-2002)is introduced in detail.2.According to the experimental investigation on six specimens of abnormal joints under low cyclic reversed loading, can have a comprehensive understanding of anti-seismic behaviors of this kind abnormal joints. The different between J-7 and J-11,J-12 were discussed in order to analyze the seismic behaviors of haunched beam joint and cross reinforcement joint, such as, the crack,full-crack load, failure behavior, stiffness, ductility and energy dissipation. In such applications, these measures can refrain bar slip effectively.3.On the basis of the experiment, a mathematical model of quadruple flexural resistance is applied to abnormal joints with equivalent high of joint core, and comparison with the experimental results are in good agreement. Deformation and failure type is also predictable with the model,and bond-slip of beam bars passing through joint is a key cause of joint failure.4.On the basis of test results and theoretical analysis results, the design recommendations for abnormal joints and construction measure for abnormal joints are suggested in this paper.
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