Research On Anti-floating Key Technology Of Underground Engineering Combined With "Structurural Anti-floating And Drainage"

This paper mainly uses the method of "structural anti-floating and drainage" to study the anti-floating design of the entire building construction process and the use process.Aiming at the rainfall and the amount of rainwater in the extreme weather conditions and the seepage of the water inside and outside the pit,the anti-floating design considering the combination of "structural anti-floating and drainage" under different working conditions in the construction process is proposed,and a new natural drainage system is used to reduce the anti-floating head in the foundation pit.Firstly,through the analysis of existing anti-floating design and anti-floating theory,the seepage characteristics and basic laws of groundwater are expounded,introduced the influence of anti-floating structure and anti-floating head value on the floating problem,and analyzed the common problems in the anti-floating design of buildings.Secondly,in view of the basic problems of the construction process,the working conditions and the changing anti-floating ability are proposed.According to the water volume of the construction process and the anti-floating ability of different working conditions,the displacement and anti-floating design of different working conditions in the construction process are calculated and analysis.Thirdly,by analyzing the common drainage measures in the existing use process,a new natural drainage system is proposed,and detailed design and analysis of each part of the system are carried out.Finally,the natural drainage system is combined with the drainage of the site.To guide the rainwater into the urban pipe network to ensure the stability of the water level in the foundation pit,and at the same time effectively reduce the structural anti-floating design.Fourthly,a test model is made to simulate the boundary seepage flow of the external structure of the underground structure and the soil contact surface at different water level.The influence of the outer structure of the underground structure on the catchment in the foundation pit is studied,and the boundary seepage effect formula is proposed according to the test results.Using the SEEP/W module in GeoStudio software to carry out finite element analysis on the boundary seepage effect test conditions,analyze the boundary seepage flow of each working condition,and verify the rationality of the boundary seepage effect formula.Finally,combined with a project case,the water level in the foundation pit during the construction process and the use process of the project is analyzed,and the corresponding anti-floating design and natural drainage system design of "structural anti-floating and drainage" combination are proposed.