Study On Lectotype Of Underground Garage Floor Under Different Thickness Of Covering Soil

With the economy being in a sustained high-speed stage In China,that more people,more cars,but less Parking space has become a common problem for the large or medium-sized city in domestic,and how to park safely and quickly has become "chronic illness" in city development.Then for the shortage of city land and other resources,how to develop and constructed the underground garage has become the effective way to solve the parking problem.As accelerating urbanization in China,the development and utilization of underground space attracts more and more attention,especially the large span one.And the underground garage has become the solution to alleviate the shortage of city land and other resources.As is known,the weight and cost of floor system occupy a large proportion in the engineering,and the form of the floor structure in the underground garage is also complex and diverse.The design and selection of floor plan of underground garage is a comprehensive science,and there are mainly the overburden load and fire engine load withstanding in the upper part of floor.For a variety of factors and constraints,we need fully considered the characteristics of all the floor structural systems and deal with problems case by case to design and select the floor plan of the underground garage rationally and scientifically,then the best floor plan of the underground garage could be acquired after balancing all the conditions.According to "the specifications in garage building design" and other relevant regulations,we select three common models in considering the driving laws and then get parameters of the optimal grid by theoretical calculation and comparison of values of common structural grid.Overburden thickness,which directly affects some structural indicators,such as the amount of structural steel and basic deepened,become an important factor in the selection and cost of the floor in underground garage.In the dissertation,based on the factors affecting the overburden thickness,we select reasonable range of the overburden thickness to analyze the structure of the floor in the underground garage.In the dissertation,taking a project example for background,we analyze the economic performance of four commonly used programs of the structure of the floor in the underground garage in different overburden depth by PKPM software,including primary and secondary beam structure,cross beam structure,beamless floor and haunched big cored.According to the results we make engineering measurement and valuation in the four forms of structural design of the floor in the underground garage,and then determine the economic indicators over the structure system of the floor in the underground garage,such as the amount of material,construction costs and so on.Finally,we determine the selection of the plan of the floor in the underground garage by considering the technical and economic indicators in the floor of the underground garage in different structure,and determine the optimal design under different working conditions by discussing the pros and cons of each plan,which provide a reliable basis for selection of the design phase.