A Comparison Study Of Floor Slab Structure Scheme On The Reinforced Concrete Underground Car-park

With the rapid economic development,the accelerated pace of urbanization and the expanded scale of city size in our country,there are many vehicles and people in major cities.In the process of social development,parking has become an urgent problem.The current situation of scarce urban land resources and near saturated above-ground development make underground space attract much attention,building an underground car-park becomes an effective way to solve the problem of parking difficulty.How to use underground area,increase parking rate as much as possible,reduce the construction costs of underground car-park is getting more and more attention from real estate developers and designers.The underground car-park floor slab system is the horizontal load-bearing structure of the base structure,transferring the load to vertical load-bearing structure,both form a whole for the common utility structure.The proper selection of the floor slab system has a significant impact on the structural stress,normal use,project cost,performance and construction methods,etc.This article through YJK architectural design software under specific project conditions models and designs the four common underground car-park upper structure systems: 1)Two-way rib beam floor slab system,2)Cast-in-site well beam floor slab system,3)Cast-in-site plastic shell ribbed floor slab system,4)GBF cast-in-site concrete bamboo core hollow floor slab system.Combining theoretical analysis,perform quantitative analysis and comparison from the aspects of component dimension,structural deformation,structural stress,project cost,etc.Considering comprehensively the factors such as performance and construction methods,establish different structure forms of evaluation index system for underground car-park's upper structure by using subjective empowerment method,and compare quantitative indexes(economic and technical aspects)and qualitative indexes(performance and construction management)of four structural plans.Considering the structural performance and height advantages of the floor cover,the performance of GBFcast-in-site concrete bamboo core hollow floor slab system is the best;Considering the aspects of structural cost and material consumption,the construction cost of GBF cast-in-site concrete bamboo core hollow floor slab system is the highest,and the consumption of building materials is the least,the cost of two-way rib beam floor slab system is the lowest,but the consumption of steel and concrete materials is very high;Considering the use of performance and construction management,there are general use performance,simple construction process and easy management in two-way rib beam floor slab system,it is most suitable for application in underground car-park projects with low performance requirements.The structural scheme with the best overall performance through comprehensive evaluation in the case of this project is the two-way rib beam floor slab system,providing designers with a reference for initial design.