Calculating On Period And Seismic Of Light-Steel And Concrete High-rise Mixed Structure

As a new housing system, low-rise light-gauge steel housing has a lot ofadvantages, such as light weight, good seismic performance, green materials, recyclableand rapid construction. However, it dose not fully adapt to China,which faces to thesituation that a rapidly growing urban population and land shortage. The light-steel andconcrete high-rise mixed structure in this paper is a main-sub structure system, whichcontains concrete main-structure and light-steel sub-structure. The high-rise mixedstructure, making full use of each materials, is the most effective way thatcold-formed light-steel used in high-rise buildings. At the same time, the light-steel andconcrete high-rise mixed structure also provides an effective way for the construction ofthe housing industry.Establish the main-structure analysis model in light-steel and concrete high-risemixed structure by being simplified to a real structural model of high-rise concreteresidential buildings in this paper. Make use of SAP2000structural analysis and designsoftware to create light-steel and concrete high-rise mixed structural model with layer2and3light steel. Doing the model with modal analysis and component internal forceanalysis under frequent earthquake, getting some preliminary conclusions.1) There is not a big difference between light-steel and concrete high-rise mixedstructure and traditional concrete high-rise structure in vibration mode and coefficient ofmass participation but in period and modal stiffness.2) There are three factors that reducing period, the total height of structure, thenumber of floor of light-steel sub-structure and the OSB slab in the light-steel wall.3) Comparing analysis on the rate of period reducing between light-steel wall andmasonry infill wall, light-steel wall has a less rate of period reducing. When designmain-structure, period reduction factor can be added0.05~0.1to the value specificationconsidered.4) When do seismic analysis on light-steel and concrete high-rise mixed structureunder frequent earthquake, concrete main-structure and light-steel sub-structure shouldbe considered separately. It can use concrete main-structure without reducing periodwhen calculating internal force and the stiffness model when calculating structuredisplacement.5) Light-steel structure has different seismic acceleration values on the different floors in the main-structure. When light-steel structure is only supported on the concretestructure, its storey shear force is as the same variation on each main-structural floor asthe seismic acceleration trend. It is the most important factor that lateral connectionsreduce light-steel structure storey shear force and make all the light-steel structurestorey shear force next to the same value. The light-steel wall connecting at the top,which can not reduce the storey shear force, on the contrary, will increase its shear forceat the bottom and top floor.