Bracket-type Vertical Load Transfer System for Heavy-load Column Strengthening: Design and Application

In the column strengthening under the beam support, for the columns with large section size, heavy load, and defects, a new type of load transfer system (LTS) was proposed: the bracket-type vertical load transfer system of reinforced concrete, which is composed of supporting columns. For the supporting columns on the load-leading layer, taking the column bottom pressure force and pressure distribution curves of the cross sections as two analytical indexes, the load transfer mechanism of the LTS was studied through finite element simulation. The net distance between the supporting column and the original column and the horizontal lap length ratio between the supporting columns were two important parameters, which mainly affected the variation law of the bottom pressure force. For the part of the frame beam between the supporting column and the original column, the critical position of its deformation form has been obtained, so that the maximum limit of the net distance was determined. The pressure distribution curves showed that the load transfer was in the form of an inner arched path. Through the engineering application, the real-time monitoring showed that the LTS could satisfactorily complete the load transfer work.