The Research On Torsional Behavior Of The Steel-framed Tridimensional Parking Structure

With the rapid development of Chinese economy, automotive industry andconstruction of transportation infrastructure, the number of automobiles has beenincreasing, which makes the parking problem worse in the public places of large cities.Thus the traditional parking mode can no longer satisfy the parking needs. So it is aninexorable trend that the traditional parking mode should transform to the modernthree-dimensional parking mode. However, the research on the three-dimensionalparking structure is still comparatively rare, so it is significantly necessary to developsystematic study on this issue.Recent researches have been focused on the single library garage, few studieswere carried out on the double library garage and combined garage. With differentlayouts of the double library garage and combined garage, the two main directions ofstiffness are greatly different, which makes the structure sensitive to torsion. In thispaper, the research is concentrated on the torsional performance of vertical elevating(tower) parking structure, the torsional behavior of this structure is studied under theeffect of torque induced by wind. The paper mainly includes the following contents:The development and application of three-tridimensional parking structure werebriefly reviewed. The fundamental components and composition characteristics of thisstructure were explored. The theory of torsion resistance ability of structure wassummarized. The control index of torsional deformation in the specification wasanalyzed.The calculation formula of the torsional stiffness and torsion angle for thethree-tridimensional parking structure was deduced by using the simplified model.Actual calculation examples showed the accuracy of the formula. The torsionalbehavior of different types of lateral brace was compared by the presented formula.By adopting different plane layouts, different types of lateral brace and differentmulti-story spanned brace of combined tridimensional parking structure which iscomposed of two parking structures in a certain way, the static performance of thisstructure was compared under the effect of torque induced by wind. Then, based onthe composition characteristics of this structure, the influence of bracing stiffness,stiffness ratio of beam to column, arrangement of tie beam of frame, story height ontorsional behavior of structure were investigated and the reasonable parameter valuesand optimal arrangement of structure were obtained. Finally, due to mass eccentricity caused by uneven distribution of automobiles, the torsional behavior of structures wasstudied. Through comparing the capability of resisting mass eccentricity, a relativefavorable bracing form was developed, which provides theoretical basis and referencefor the practical engineering application of such structures.