SEISMIC REROFITTING OF EXISTING CONCRETE STRURES WITH BRBS INSTALLED IN ADDITIONAL CONCRETE FRAMES

A seismic retrofitting scheme of a concrete building, constructed based on Chinese Standard TJ11-78, is designed by using BRB concrete frames. Comparisons are made on seismic behavior between the original and the retrofitted structure in terms of seismic actions, displacement, the ratio of axial force to strength, and inter-story shear forces, etc. Nonlinear static pushover analysis and dynamic analysis are conducted. Plastic hinge status, hinge distribution features, and inner forces envelopes are compared. Results have shown that the retrofitting technology alleviates seismic forces on existing frames, and avoids the significant axial compression force, shearing force, and inter-story drift angle occurring at the bottom stories of the original frame. By applying this method, energy dissipation and seismic reduction can be enhanced, and better seismic behavior of concrete frames can be achieved. Static lowly cyclic loading tests are also conducted, demonstrating effective seismic damage reduction and plastic hinge distribution transfer. With this method, indoor wet construction work can be avoided, which is beneficial for both constructors and residents.