Study On Human-induced Vibration For Steel-concrete Composite Floor Ofa Super-high Rise Building

Steel-concrete composite floor hasalmost become the standardsolution for high-rise buildings in recent years because of its light weight, high strength, and easy construction. There are several kinds of composite floor, like solid-web steel girder-concrete composite floor, steel truss composite floor, honeycomb steel concrete composite beam, of which the most widely used form is solid-web steel girder-concrete composite floor. Steel truss composite floor is rarely used for typical floors in high-rise building but it has the advantages, like reasonable stress. Truss composite floorcan markedlyincrease the net storey height because pipelines can be easily set through the web members.At present there is no clear design specification and analytical tool in China to evaluate composite floor systems for vibration serviceability due to human activities. With the emergence of higher requirements for building functions and floors of larger span, more scholars and engineers begin to study in this field. This research includes literature research, theoretical analysis and numerical calculation. Analysis and calculations were done on vibration serviceability due to human activities of truss composite floor and steel-concrete composite floor. Key design parameter and suggestions for vibration serviceability were put forward.The main studies and contributions in this dissertation are as followings:1. Introduced the background and current research results of vibration comfort of floors. Existing design specification and evaluation rules are summarized. Analytical work were conducted onthe problems in avalibleresearch results and existing design specification in China.2. Comparison was made between the results of fine finite element model and experimental studies of other scholars. Accuracy of the finite element modal analysis was verified. Put forward some suggestion of boundary conditions and other parameters for finite element model in vibration comfort analysis.3. Finite element transient time history analysis was made using different types of walking excitation.Single-people and multi-people excitation was taken into consideration, including fixed single foot force method, mobile single force method, walking excitation. After theoretical analysis and the comparison between results of time history analysis, fixed single foot force was chosen to be a standard loading for vibration comfort analysis. The step frequency of the excitation should coincide with the resonant frequencies of the floor system.4. Transient dynamic response of two kinds of composite floor under fixed single pedestrian walk force was computed. Design suggestions were made based on the calculation result of multiple time-history analysis.Several design parameters were taken into account, including depth-span ratio of the beam/truss, thickness of the concrete slab, damping ratio, additional dead load.5. Made vibration serviceability analysis of a super-high frame-core tube building with steel-concrete composite floor system. Optimization suggestions were given and a truss composite floor plan with a smaller amount of steel was put forward.