Study And Application On Practical Combined Design Method Of Seismic Energy Dissipation And Isolation Structures

In this paper,the actual engineering structure located in the high intensity area(9 degrees,near-field coefficient 1.5)was used as the research carrier,and the finite element software YJK,ETABS and Perform-3D were used for analysis.Based on the current specifications,the paper investigated and studied the shortcomings of the current Combined Design methods of seismic energy dissipation and isolation structures.The major problems discussed and solved were as follows: 1)A practical Combined Design method for seismic energy dissipation and isolation was proposed,and the design process of seismic energy dissipation and isolation structures under different structural design order was summarized.2)The engineering case analysis of the viscous damper-isolation structure and the metal damper-isolation structure was carried out,and the performance characteristics and differences of different types of damper-isolation structures were revealed under different design orders.3)The engineering case analysis of the viscous damper-isolation structure and metal damper-isolation structure with structural optimization were carried out.The structural performance and the amount of concrete and reinforcing before and after optimization were compared in different design orders.By comparing and analyzing the above contents,the conclusions are as follows:(1)For viscous damper-isolation and metal damper-isolation structure after isolation,structural fundamental period,horizontal displacement of seismic isolation bearing,maximum inter story drift under rare earthquake with two different design orders have the considerable difference.The damping coefficients of the two design orders were different resulting in different peak ground accelerations of the input earthquake waves after conversion.Therefore,some results of the energy dissipation design part will be quite different such as additional damping ratio and maximum inter story drift of upper structure.(2)For the viscous damper-isolation and metal damper-isolation structure,the amount of reinforcing under different design orders is different,so that the material usage and economy of two design methods are different.In the case of frequent earthquakes,for the viscous damper-isolation and metal damper-isolation structure,no matter the upper structure is in the condition of shear force distribution of inter story drift distribution,the structural response results of “energy dissipation design first” and “energy dissipation design first” all enclose the results of “direct design method”.Therefore,the two methods,“energy dissipation design first” and “energy dissipation design first”,are relatively safe and conservative.(3)Regarding the comparison of damping coefficient,whether the damping coefficient takes the shear ratio under the enveloped value of three waves or the average of seven waves,the damping coefficient may appear to be equal to,greater or less than the case of energy dissipation design first.For practical engineering applications,it is recommended to compare the structural performance of the two schemes of “isolation design first” and “energy dissipation design first”,and select a scheme with a more satisfied damping coefficient.(4)Due to the optimized structure adds dampers,it can only be redesigned with the alike design order as “energy dissipation design first”.After the optimization,performance indexes of the structure meet the requirements of the specifications meaning that the structure has considerable seismic performance.(5)In the case of frequent earthquake,after structural optimization,the design of“isolation design first” or “energy dissipation design first” is relatively safe and conservative.Optimizing the viscous damper-isolation and metal damper-isolation structures save the structural material usage,is economical and increases the effective occupant space.For the actual engineering with combined design of energy dissipation and isolation,when structural optimization is carried out,it is recommended to compare the results of the two different design orders and choose a more reasonable solution.