Wind-induced Interference Effects On Tall Buildings Considered Fluid-structure Interaction

Wind-induced responses of tall buildingds is a no longer novel topic in the field of structure,however with rapid development in cost of land and numbers of high-rise buildings,this topic keeps everlastingly new.Wind-induced interference effects on tall buildings is one of the new derivative subject.The existing researches on wind interference in high-rise buildings are mostly based on the wind tunnel experiment and rigid model numerical simulation,which could not obtain the aeroelastic parameters in wind interference effect.The load code of wind interference only provides the amplification coefficient of shape coefficient considering two high-rise building with same section.It is not enough for the high-rise building wind engineering design,all in all,the relevant norms on wind interference are relatively scarce.In this paper,baced on the CAARC standard tall building model,considering wind-induced responses between two tall buildingds and fluid-structure interaction(FSI),numerical simulation analysis is carried out.Mainly make the change of parallel and serial spacing between tall buildings and the dimensions of interfering model,finally,the main conclusions are as follows:(1)For the isolated CAARC standard tall building model,the LES method high precision for simulation of high-rise building,consideing the influence of FSI,the peak displacement of the CAARC model could be large and this large scaled deformation will affect the distribution of wind pressure in flow field,so the effect of FSI should be considered in the analyses of wind-induced responses of tall buildingds.(2)In case of tandem arrangement,the wind pressure coefficient(Cp)on the front surface of a principal building are negative,the cp on the other surfaces decreases,if the spacing is greater than 12DX(along-wind width),the interference effect on wind pressure could be ingnored;if the spacing is more than 24Dx,it is not necessary to consider the effect of wind vibration coefficient,and try to avoid the case that the spacing is 4Dx in the construction planning.(3)The channeling effects could oberzeved in case of parallel arrangement,when the spacing is little,the wind speed can be increased by 10%.Both the Cp and the top node displacement of a principal building are enlarged,but the wind vibration coefficient(?)has no significant change.In other words,in tandem arrangement case,the dynamic response of a principal building is enlarged,while in parallel arrangement case,the static response of a principal building is enlarged.(4)If the height of a interfering building(Hr)is less than the height of a principal building(H),the smaller interference would be make in flow field,if Hr is greater than H,the interference is larger,but with the increase of height,no significant change in flow field.If Hr smaller than 0.5H,negligible interference;if Hr larger than H,the interference factor of Cp can be 1.5 while P can be 2.0.If the width of a interfering building(Br)is the half of the width of a principle building,the interference factor of P of the top node may reach 1.7 while the displacement is small.(5)Employing FSI numerical simulation to analysis the specific project,the result of base shear and bending moment is in accordance with wind tunnel test data.In order to improve the accuracy of torsion value,it is necessary to make further im-provement on the turbulence model.The surrounded tall building make larger wind speed,peak negative pressure and intensity,so it is recommended to improve the wind field while planting trees.