Study On Seismic Behavior Of Joints Of Monolithic Precast Concrete Frame Structure With Specially Shaped Column

Prefabricated concrete structure is the important structure forms of the current construction industrialization, and it’s in line with the direction of green and sustainable development. At present, the construction of new rural areas is mainly in the low and medium level buildings, and urgent need to develop a new type of green low carbon building form. The special-shaped column frame structure can avoid the lobes appear in the room, and the column of it is flexible arrangement, besides it is lower cost, so it can be suitable for middle and low level buildings. However, there are few researches on the frame structure of the assembled special shaped column at present, and the seismic performance of precast concrete structures and specially shaped column frame structures have been concerned by the people. So this paper is aimed at the seismic performance of the frame structure with special shaped column assembly.This paper takes the demonstration project as the prototype, experimental study the assembled monolithic cast-in-place node of four nodes and four full-scale under the action of horizontal low cyclic loading tests respectively. The failure process and failure mode of two kinds of construction methods, and the hysteretic curves, skeleton curves, ductility, energy dissipation and stiffness degradation are studied. The nonlinear finite element simulation analysis and parameter analysis of the test model are carried out by using the MARC finite element software, and Systematic study the effects of various parameters will affect the seismic performance of joints. The research results have been successfully applied to the dormitory building of Shunyi Beijing wild animal rescue center. Through the research and analysis, the following conclusions are drawn:(1)Compared with the cast in place node, assembly nodes enter the yield stage earlier, and a slight decrease in the ultimate bearing capacity. Assembly node is positive, the limit load of reverse loading is 90% to 100% of the same structure, and structural ductility is improved.(2)The stiffness degradation velocity of assembly node is close to cast in place joint, the average stiffness degradation curve is basically the same, and the energy dissipation performance of the assembled joints is similar to the cast in site.(3)The push-over curves obtained from the finite element calculation are in good agreement with the experimental framework. Ultimate bearing capacity of joints, limit displacement by axial compression ratio and beam reinforcement diameter have greatly impact. The core area of stirrup spacing, concrete protective layer thickness has little effect.(4)Based on the experimental and theoretical research, the prefabricated assembly frame system was successfully applied to the construction of the Shunyi Beijing wild animal rescue center dormitory building project, and achieved good results:The construction speed and quality are improved, and reduce environmental pollution at the same time.