The Impact Analysis Of Crowd Load Upon The Large Span Floor Vibration Of Station Hall

With the rapid development of railway transportation in China, the functional requirements become higher and higher, and certain new variations and tendencies have arisen in the design of railway station, one of which is "Building-Bridge integration" structure system. There are large span floor, lighter floor, lower frequency, more sensitive to crowd load in the new elevated station hall layer. This paper discusses the influence of crowd activities upon the large floor of station from field test and finite element simulation. The main work and research results are as follow:1. Field test. Test the floor vibration response of a variety of crowd’s regular activities in Beijing South Station during the close period in the night, such as standing, sitting, walking, running, stepping, jumping, etc. and record various situations which are237sets data of80in total..2. Modal Parameter Recognition. Stochastic Subspace Method is superior to other modal parameter recognition methods for output signals about environment excitation of which crowd load in the test is available to be the source of vibration in accuracy and stability of calculation. On the basis of test data characteristics, this paper writes Stochastic Subspace MATLAB program and processes test data to recognize structure modal parameter.3. Coupling Effect Analysis. Analyze the influence and variable regularity in floor system vibration and dynamic behavior of parameter variation, such as, postures, number, density, etc, of crowd from the vibration response in floor system and modal parameter changed results, and then analyze people-structure coupling action mechanism.4. Finite crowd element walking process simulation. In ANSYS, new dynamic system is composed of mass-spring-damping element, which is simulated from human body element, and Beijing South Station floor system. Exert walking excitation upon it and simulate walking process on the floor system to analyze vibration behavior of people-structure coupling system according to various conditions of walking people and walking frequency.