Study On Technical Economy Of Seismically Isolation Design For Shear Wall Structures

With the promulgation and implementation of the fifth generation of earthquake zoning map in China,many areas of ground motion parameters have been improved to varying degrees in China.Because the high aspect ratio of the high-rise shear wall houses are larger,the wall limbs have greater tensile stress under the medium earthquake action.By increasing the thickness of the shear wall and setting the section steel,it not only increases the weight of the structure,causes the earthquake force to increase,but also increases the construction cost obviously.Compared with the traditional earthquake resistant structure,the force of the superstructure is obviously reduced,and the thickness and reinforcement ratio of the upper wall can be reduced by reasonable seismic isolation design,and the cost of the project can be reduced.The seismically isolated structure has obvious advantages over the traditional seismic structure in high seismic intensity area.In order to study the technical economy of high-rise shear wall dwelling houses adopting seismically isolation design in high-intensity seismic areas,comprehensive comparisons were made for a shear wall structure before and after using isolation design.The bottom shear forces and inter-story drift angles of the seismically isolated and the non-isolated structures under frequent earthquakes were checked respectively.The story shear and story Overturning moment of the seismically isolated and the non-isolated structures under frequent earthquakes were checked For seismically isolated and non-isolated structures,the energy dissipation performance,inter-story drift angles,deformation angles of shear walls and deformation angles of coupling beams under rare earthquakes were compared and analyzed to study structural damage conditions.On this basis,the relationship between the amount of materials used,engineering cost and fortification intensity in both seismically isolation and non-isolation structures was discussed.The analysis results show that,Through reasonable isolation design,the horizontal seismic decrease coefficien of the high-rise shear wall dwelling houses can be controlled within 0.38.According to the regulations of Code for seismic design of buildings,The fortification intensity of the superstructure can be reduced by 1 degrees for structural design.;the total seismic shear force and overturning moment of the structure can be reduced about 60%;the maximum inter-story drift angle can be reduced more than 40% and 50% under frequent earthquake and rare earthquake respectively;the maximum displacement of the isolation floor can be reduced significantly by setting viscous dampers;shear walls are basically in elastic state,and even the damage degree of coupling beams is reduced greatly.For region with 8 degree fortification intensity(0.3g),the seismically isolated structure has significantly less amount of rebar and concrete used and lower engineering cost than those of the non-isolated structure.