The Formation Of Crowd Loads And Research On Crowd-Structure Interaction At Temporary Grandstand

Temporary grandstands can be widely used in a variety of performance and sport events,due to its excellent adaptability for various places and convenient setup and/or disassembly.However,it can gather massive crowds during a short time,and the excessive vibration of structure even collapse can be induced by crowd load's abruptness and synchronize.People pursue spiritual of these performance and sport activities would be seriously impeded.To accurately reveal crowd load rule and computing mode,as well as investigate the interaction between human and structure,which is the crucial research work in temporary grandstand study and what confronting main task in intelligent computation on the field of temporary structure nowadays.For decades,most of the reasearchers are however focused on explaining the interaction between human and beams,floors,footbridges,permanent grandstands and so on.As far as we know,little research has investigated temporary grandstand.So there are still a lot of interesting and unresolved problems in this area.For example,human self-excited load can be varied significantly between different persons in different countries,the existing load models are maybe not available for representing the stochastic variations in domestic human.Besides,the dynamic responses of temporary grandstand and human dynamic parameters are ambiguous,which incurs heavy interest to ecplore,whether spectator can be tolerant or not.What is more the available comfortability limit values derived from the previous small number of guideline and literature are still necessary investigated to further.Supported of National Technology Supported Plan(grant number: 2014BAK14B05)author deeply and intensively investigates in processing of crowd loads and analyzes the human-temporary grandstand interaction model.Author found the shifting law of temporary grandstand crowd load and presents the comfort level design criteria.The main research work as below:(1)According to the current research situation of China human loads,author employs measure jumping board and Three-Dimension acquisition data device to collect the body sudden load and rhythmic activates caused by self-exciting action and model the load information.Author has established the usable design method of self-excitation crowd load and human body load through the residual form eigen variable.It also analyses the body move load curve characteristic parameters change rule.Author presents the crowd load jumping and swaying models.The dissertation first gives the calculation theory aiming to China spectator crowd loads.(2)This investigation has studied on the coupling mechanism between crowd loads and provisional bleacher.It also measured the coupled effect of crowd load applied on spectator stand occupied by persons and excited by random environmental vibration.It reveals the structural dynamic performances changing mechanism of grandstand lateral impacted by pedestrian load.This dissertation proposes the static pedestrian load dynamic parameters and presents the interaction model between the crowd load and temporary grandstand.(3)A three degree of freedom(3DOF)couple model for simulating the interaction between crowd and temporary demountable grandstand(TDG)is established.According to the measured parameters,the model is analyzed when considering the jump and sway loads component which are important for safety of temporary grandstand respectively,the effects of model parameters for structural dynamic response are systematically analyzed and the noticeable parameters are proposed.(4)Annoyance rate model is presented to describe the temporary grandstand vibration serviceability degree based on crowd vibration sensation test.This dissertation also gets the relation of crowd annoyance rate with acceleration.Author comes up with the quantitative vibration serviceability design method and the limited value of temporary grandstand under different frequency.Combined temporary grandstand node stress with whole response test data,author has calculated the big gap finite element model(FEM)overall simulation and model updated by made use of ABAQUS so as to demonstrate the research results validation.This dissertation discovers that the coupling model spatio-temporal property of the crowd load against temporary grandstand.Whatever practice or theory each shows that the research work and its results can be directly afforded as to design code and principle to temporary grandstand effectively and that possesses significant practical value.