Research On Floor Vibration Response Under Walking Loads For Serviceability

The paper focus on the floor serviceability under normal use, the main achievement are:1) Researches on random walking force model. Introduce Zivanovic’s random model, pointing out its disadvantage of complex operation. Proposes a new semi-random model,which can reflect true walk force’s non-periodic nature, also can be directly used in time-history analysis. Validates the model by in-situ test data.2) Researches on the interaction of pedestrians and floor. Analysis the SMD model, pointing out its problem by theoretical derivation and FEM analysis. Discourses the rationality of taking the walking force as load.3) Referencing the research in the field of biomechanics and transportation, Proposes an new crowd walking force model. The model considers the relativity of crowd density and average walking frequency.4) Organizes86pedestrians participating an in-situ test on an26m long steel bridge. Tests the bridge’s acceleration in40conditions. Based on test results, Proposes the methods of processing group walking and crowd walking.By analyzing the test video, Proposes the formula of calculating load duration of a single footfall.5) Derives the formula of calculating floor response under single pedestrian, pointing out the disadvantage of current regulation. Proposes a new method which take the pedestrian’s moving nature and limited walking time into account.6) Make the following definition clear:synchronization probability coefficient, equivalent response coefficient, equivalent load coefficient, equivalent crowd dynamic load factor. Proposes the Monte Carlo simulation method to calculate the floor response under crowd walking.Derives the formula of calculating floor response under crowd walking by random vibration theory. Proposes a formula to calculate equivalent pedestrian number Ne.7) Propose an method to calculating the floor’s response under crowd walking based the model the paper given. 8) Discuss the serviceability of solid section concrete floor.In summary, the paper has studied walking force model and method of calculating floor response. Proposes a new simplified method which is better than current method. The paper’s work can push forward the study on floor serviceability.