Mathematical model and case study of wind-induced responses for a vertical forest

The concept of vertical forests is gaining popularity as it promotes the coexistence of architecture and nature in urban areas. The wind loads and dynamic responses of buildings may be impacted by the presence of vegetation. A wind-induced motion equation of vertical forests was formulated in the preliminary stage of research, assuming that tree cover is enclosed with curtain wall. The model was used to analyze a case. We used the time history of wind pressure attained from wind-tunnel tests of the host structure to calculate wind-induced responses. To investigate the contribution of the vegetation, three cases were analyzed: the original structure, the vertical forest and the host structure with an ETMD (equivalent tuned mass dampers). The impact exerted by tree cover with specific parameters on wind-induced responses was analyzed. The results show that tree cover significantly reduces vibration of the host structure under the action of wind loads, though the vibration-absorbing effects exerted by tree cover are less than that of the ETMD. Parametric analysis indicated that vibration-absorbing effects are more susceptible to the variation of natural frequency of tree cover than its damping ratio.