Study On Earthquake-resistant Behaviors And Strengthening Of Joints Of RC Frame

Based on the relative study of both abroad and home, systemic overview of earthquake-resistant behavior and strengthen methods of joints of reinforced concrete frame are obtained. The paper start with earthquake effect, first of all, the present research status of earthquake-resistant behaviors and strengthening of joints of reinforced concrete frame was summarized and introduced.Secondly, the author studied and analyzed the earthquake-resistant behaviors of joints of reinforced concrete frame from strength, deformation and ductility, respectively. According to the geometrical construction of the joint, joint of reinforced concrete frame was classified into two sorts. The stress mechanics of the joints were analyzed detailedly and roundly, and barocline perch model, shear-friction model, truss model and combinations model were introduced clearly. Based on the analysis of the primary factors which affected the bearing capacity of joints of reinforced concrete frame, the criteria of anti-seismic design of joints of reinforced concrete frame was presented. The comparative analysis of joints design in earthquake-resistant design code of several countries, anti-seismic design of joints of reinforced concrete frame in Code for Design of Concrete Structures(GB50010-2002) was introduced in detail.Thirdly, the primary factors which affected the ductility of joints of reinforced concrete frame were analyzed, and the method of ductile design of the joint was presented. The constructive measures to ensure the ductility of the joints were emphasized in the paper.At last, on the base of earthquake damage and relative test results of joints, the modes of failure were classified into four types. Cross-section increased strengthening method, sticky-steel strengthening method, wrapped steel strengthening method and FRP strengthening method were introduced and analyzed in detail, respectively. Suggestions of engineering and construction for the joints strengthening were presented by the author to give available references for engineers and technicians.