Research On Performance-based Seismic Strengthened RC Piers With SFC Precast Segments

Earthquake is listed as one of the most disaster of all kinds of natural because of its suddenness and enormous destructiveness,bringing about huge losses of life and property.Bridges damaged in the earthquake is also very common, the construction cost is high,as a traffic throat,plays an important role in earthquake relief,once suffered earthquake damage,it would lead to huge losses,and it's difficult to repair after the earthquake.Based on the digestion and absorption of existing bridge seismic strengthening results at home and abroad,mainly researched on the premise of not changing the position of plastic hinge region of how to improve the ability of RC pier seismic strengthened measures,specifically researched and developed a new type of seismic strengthening measures-RC pier plastic hinge region outsourcing precast segments of steel fiber concrete,through the ingenious design of precast segments to avoid the transfer of the RC pier plastic hinge region,to realize the improvement of bearing capacity, ductility and energy dissipation capacity.In order to explore the strengthening effectiveness of new aseismic strengthened measures,selected a RC pier of a bridge as the prototype in Mianyang,on the basis of 1:5 scale,designed and made model original pier,and then adopt the new strengthened measure to design and make two kinds of reinforced model piers-new pier and reinforced pier,based on the pseudo static cyclic loading tests and nonlinear seismic time history response analysis of piers,verified the seismic strengthened effectiveness,then put forward and checked the suitable seismic strengthening design method for RC piers.The main contents are as follows:(1)Aiming at the new type of seismic strengthened measures,based on “the basic supposition to the calculation of the normal section strength”,the formulas for calculating yield moment?maximum bending moment and yield displacement of new pier and reinforced pier are deduced,and put forward a design method of new strengthened measures;(2)Designed and made 3 model piers-1 original pier ? 1 new pier and 1reinforced pier,based on the pseudo static cyclic loading tests,the seismicbehavior and failure mode of original pier ? new pier ? reinforced pier were comparatively studied,analyzed the strengthening effectiveness of new aseismic strengthened measures,verified its strengthened design method;(3)Based on the results of pseudo static cyclic loading tests,selected typical ground motion of four kinds of site classifications to do the nonlinear seismic time history response analysis for original pier ? new pier and reinforced pier,further verified the strengthening effectiveness of new aseismic strengthened measures.