Design Analysis Of Underground Garage Girder-less Floor System Structure

With the continued development of urbanization,underground garages,as one of the effective ways to relieve urban resources shortage and land scarcity,have been widely used in practical engineering.It is widely known that floor system plays an extremely role in the whole project and can affect the structural safety and construction costs.Flat slab can be widely used in underground garage and has some advantages including making full use of the space of the underground garage,effectively lowering the floor height,reducing the project cost,etc...Compared with plain concrete floor,underground garage flat slab structure has unique characteristics.The lack of understanding of its mechanical characteristics and particularity may cause small errors.This thesis mainly analyzes the method of underground garage flat slab structural design.The author hopes to apply underground garage flat slab structural design to practical engineering and provide certain references for structural design.The main contents are as follows:(1)This dissertation illustrates the background of flat slab application and internal and overseas research actuality.The classification of floor system,its advantages and shortcomings are described in detail.And this paper also organizes its structural form,composition,loading features,and application range.(2)This dissertation introduces three calculating methods for flat slab--direct design method,equivalent frame method,SLABCAD method--and the detailed design contents,application range,similarities and differences of these three calculating methods.It also applies the direct design method to case one--non-sway flat slab structure and performs reinforcement calculations.(3)The design and calculation of the flat slab is based on a commercial office building's underground garage.Choosing the reasonable form of slab,column cap and reinforcement configuration,the design details of flat slab and structural requirements are overviewed.and carrying out checking calculation of punching on the column cap as well as slab's limit state.This dissertation summarizes the details about flat slab design process.Taking practical engineering of underground garage flat slab as an example modeling,it calculates and analyzes the flat slab by using SLABCAD method,gets the resultsthrough plate interaction design and calculation,and compares the results with those of manual calculation.