Research On Influence Factors Of The Twin Towers Conjoined Structure Under Horizontal Seismic Action

As the high-rise towers conjoined structure is widely used in the field of engineering, it is increasingly important to understand the factors affecting the stress of the conjoined structure.This paper comprehensively summarizes the structure characteristics and research status of the twin towers conjoined structure, then deeply studies the influencing factors response the earthquake of the twin towers conjoined structure, mainly includes the connection form, connection location, connection span and connection layer for the seismic response of the structure.1.To study the effects of different connection methods on seismic responses of the twin towers conjoined structureIt found that the five different kinds of connection mode barely affect the natural vibration period, vibration mode, the top floor displacement, the interlayer displacement, base shear force and overturning moment of the twin towers conjoined structure in this paper. It is because the displacement, vibration mode and frequency of the whole structure is dominated by the rigidity of the structure, local stiffness changes impact on the stiffness of the whole structure is small, but the conjoined structure make torsional vibration model corresponding to the natural vibration period have great changes, Y direction vibration mode is slightly complex than X direction.2.To study the effects of different connection positions on seismic responses of the twin towers conjoined structure.As the connection position rise, the structural natural vibration period appears the tendency of increase first then decrease, and the influence of the natural vibration period is more obvious under high order vibration mode than low order modes of; The difference of vibration mode on horizontal axis and longitudinal axis is bigger when the structure of the twin towers under different connection position; The top floor displacement and the inter-story displacement change from descend to ascend with the connection position rise, the basal shear force of horizontal axis and longitudinal axis under the different connection location increase with the connection position rising, but also has a tendency to increase after the first reduce; Connection position on the floor has a little influence on shear and the effect is not obvious.3.To study the effects of different connection spans on seismic responses of the twin towers conjoined structure.①No matter symmetric or asymmetric, connection position on the upper floor or on the lower floor, their first translation and the first torsion cycle of the structure are increases with the span increase while the increasing value is very small.To consider from the angle of mechanics, stiffness of the whole structure will cause weak by the connection span increases, in other words,connect span increase can make the structure period increase.②The inter-story shear force in the x and y to under the earthquake increases with the increase of the conjoined span, but increased modestly; The inter-story shear force above and below the conjoined tower decrease as the level increases, only floor shear force that conjoined located is bigger than the surrounding floor shear, it is because the conjoined enhance the stiffness of this layer, thus absorb more seismic force, the inter-story displacement at x is almost increases as conjoined span increases, while an increase of the conjoined floor and the floor below in the x axis is smaller than that of connection above; but connection span changes almost does not affect the inter-story displacement of the y direction.4.To study the effects of different connection layers on seismic responses of the twin towers conjoined structure.Vibration period can increase with the increase of the layer number of connection, but will not change the vibration mode of the first translation cycle and the first torsion cycle; Symmetrical structure’s Tt/Ti decreases gradually with the increase of the layer number of connection, that os to say increasing connection layer is a good way to reduce the torsional effect of symmetrical structure of the twin towers, Tt/T1values of asymmetric structure basically remain unchanged.The maximum inter-story displacement of twin towers conjoined structure is positive correlation with the conjoined layer;the base shear corresponds to the main vibration mode of x and y axises is negative correlation with the conjoined layer of the twin towers conjoined structure.