Research On The Seismic Behavior Of Unequal-height Double-tower-connected Structure

Because of the property of distinctive appearance and providing specificrequirement of building function, the double-tower-connected structure is popular withthe architects. Compare with the single-tower structure, the dynamic performance of theasymmetric double-tower-connected sutructure is more complex. So it is necessary toanalysis the dynamic performance and responses.In this paper, for the unequal-height double-tower-connected structure connectedby one storey steel truss which is at top of the low tower, the study is as follows:â‘ Using the continuous analysis method to make static analysis, the auther hasdiscussed the main factors influencing the force of connecting body.â‘¡For the unequal-height double-tower-connected structure, design exampleprograms and analysis them, the author has finished responses spectrum analysis, elastictime-history analysis and elastic-plastic time-history analysis. The author has alsoreasearched the influence caused by height and stiffness difference of two towers forstructural dynamic characteristics and seismic response.Through the above-mentioned research, the main conclusions are as followings:â‘ The first order nature vibration period of unequal-height double-tower-connectedstructure is mainly affected by the higher tower whose stiffness is weak, period is long.The first period of torsion is mainly affected by the lower tower whose stiffness isstrong, period is short; There are lots of transverse translation and torsion couplingvibration mode about structure, but almost no longitudinal translation and torsioncoupling vibration mode; There are vibration modes whose modal mass participationcoefficient is small under the earthquake, with the decrease of the height and stiffnessdefference, this kind of vibration mode will be more liable to occur.â‘¡When the connecting body is located at a certain position, the fourth ordervibration mode of the whole structure is the Y direction translation and torsion couplingvibration mode, which lead to the increasement of displacement of Y direction; Thedisplacement of Y direction is mainly affected by the stiffness of Y direction and torsionof structure; With the increasement of the stiffness and height defference between thetwo tower, under the earthquake, the Y direction of vibration of higher tower will beopposite to the lower one. The phenomenon that the vibration of two tower is out ofsynch is obvious.â‘¢For the unequal-height double-tower-connected structure, the seismic measures of the connected storey and its adjacent upper and lower storey should be strengthenedaccording to the technical specification for concrete structure of tall building. On thebasis of this, the shear capacity of the longitudinal shear wall of connected storey andY-direction stiffness of upper storey of conjoined position should be also strengthened.