Research On Design Method Of The Connection Between Infilled Walls And Frames

In view of the serious earthquake damage caused by infilled walls with rigid connection,Building Code of Aseismic Designing suggests making the column and infilled wall withdraw(open) or using flexible connection in the reinforced concrete structure. But at present, therehave been no specific provisions for the construction process and design specification of infilledwalls with flexible connection, which seriously hinder the application of the flexible connection.This paper carried out theoretical research on the flexible connection, suggested takingnonstructural components into structural design and put forward a integrated design method toensure infilled walls with flexible connection meet the anti-seismic requirements. Althoughinfilled walls are just nonstructural component, these seem significant.Considering infilled walls only bear the earthquake action caused by self-weight, in addition,the in-plane rigidity and bearing capacity are big, design of infilled walls with flexibleconnection is just to the out-plane bearing capacity and stability.The value of gap width should consider various comprehensive effect, it needs to allow thelateral free deformation of the structural components, consider the influence of gap width on thesupporting effect provided by the annectent reinforcing bar and meet requirements of buildingfunction.This article analysed mechanism of action of vertical annectent reinforcing bar and putforward a new computation model—the base is the fixed end, while the top is a horizontal linearelastic support.Out-plane loads mainly include the wind load and the horizontal earthquake action, inaddition, the effect of the lateral displacement of storey should be considered.Based on the above computation model, the paper proceeded the aseismatic and non-aseismatic checking of out-plane bearing capacity and got the ultimate load.In the checking of bearing capacity, the nonlinear support is simplified to linear elasticsupport, the change of boundary conditions would affect the bearing capacity of components, amodifying factor is introduced to revise the difference. ABAQUS is used to simulate mechanicalproperty of infilled walls to determine the value of modifying factor. After analysis, for120mmwall, the value suggested is0.80, for240mm infilled wall, the value suggested is0.70, for370mm infilled walls, the value is0.65, in addition, thick infilled walls is difficult to adapt theeffection of the lateral displacement of storey, so it is better to apply the thinner infilled wallsinto structural design.It needs to check the anti-collapse performance of infilled walls with flexible connection,after theoretical analysis, this paper assume structural collapse critical state and put forward thecorresponding check formula, and get the minimum requirements of the ratio of the annectentreinforcing bar.Considering the limitations of infilled walls with flexible connection, rigid connection playsa leading position in short period, so the research on the impact of infilled walls on theanti-collapse performance of structure is carried out, the object of study included four kinds offrame structures, a pure frame, ACC infilled frame, ordinary8inch infilled frame and ordinary 12inch infilled frame, CMR method is adopted to evaluate the anti-collapse performance. Theresult shows that infilled walls can increase the stiffness and strength of structure and reducestructural ductility, strong infilled walls severely reduce the anti-collapse strength and thestructural emergency capacity, while weak infilled walls almost have no effect on theanti-collapse probability and can improve the structural emergency capacity. So the papersuggests, in the subsequent structural design, the designer must control the infilling strength ratio,and the ideal infilling strength ratio is0.35. In view of the infilling strength ratio of the aeratedconcrete masonry is less than0.35, so the application of ACCinfilled walls would be promoted.