Investigation On Risk Of Vortex-induced Resonance For Super High-rise Building By Wind Tunnel Test

In recent decades, super high-rise building is developing toward light weight, high flexible and small damping, so the possibility of damage or destruction due to vortex-induced resonance(VIR) is enlarged significantly. However, the risk and harmfulness of VIR is still not fully recognized by researchers,and the related research is not comprehensive. Therefore, several related critical problems were studied in this paper, including:a. VIR excitation mechanism and the occurrence probability of super high-rise building with typical section shapes in a variety of wind fields, b. Response level and its instability characteristics of VIR, c. Influence of body shape and eccentricity to VIR. Specifically, the following works were carried out in this paper as flows:1. Based on the comparative analysis of vortex induced vibration response by SDOF and MDOF aero-elastic model test, an improved design method of MDOF model was proposed. On the basis of the improved design method, the experimental objects including three square cross-section models, two rectangular cross-section models, a triangle cross-section model, a hexagon cross-section model and a practical engineering high-rise building were made. Through wind tunnel tests of above models with different Sc number, aerodynamic shape, eccentricity in typical terrain category, the vortex-induce vibration(VIV) response and surface pressures were measured and analyzed.2. Through the analysis of aerodynamic damping and aerodynamic stiffness parameters, an improved empirical formula to evaluate aerodynamic damping was proposed, thereafter, a new procedure to assess vortex-induced response of high-rise flexible building was deduced with the consideration of aerodynamic stiffness and peak parameter.3.Based on the synchronized measurement of surface wind pressure and VIV response of MDOF model, the phase relationship between surface pressure and VIV displacement were studied, which explained the intermittence of VIR and instability of VIR response amplitude. Thereafter, a closure model to evaluate the occurrence probability of vortex induced resonance was established, by which the occurrence probability of resonance and no-resonance can be calculated.4. The body shape characteristics of existing super high-rise building were discussed and a corresponding classification was given. Through a series of MDOF wind tunnel test with aerodynamic shape optimization, the effectiveness of several typical aerodynamic optimization was discussed. Finally, the MDOF model test of a practical tall building with 838m high was carried out.