Comparison And Analysis Of Dewatering And Drainage Schemes For Deep Foundation Pit Of Huangtiandang Sluice Weir Project

With the development of urban water environment regulation and the construction of river level regulation projects inside and outside the city,a large number of water network control projects around the lake and along the river have emerged.The dewatering and drainage of deep foundation pit is an important link in the construction of such projects,and the design and optimization of dewatering and drainage scheme is an important content.This paper has carried out the following work on the design and comparison of dewatering and drainage scheme of deep foundation pit of huangtiandang gate and weir project:1.According to the basic theory and engineering situation of foundation pit dewatering,the water inflow of foundation pit is determined;Through the calculation of the stability of confined water against sudden surge,the safe state of the excavation surface of the foundation pit is analyzed;By simplifying the Bishop method calculation,the stability of the design grading slope is analyzed to check the working condition for the preliminary design of the subsequent precipitation scheme.2.Through the analysis of the characteristics of common foundation pit dewatering forms,the applicable conditions of various dewatering methods are clarified.Then,the dewatering and drainage of deep foundation pit of huangtiandang sluice weir is preliminarily designed with open drainage of foundation pit,pipe well dewatering and light well point dewatering respectively.The scheme configuration is determined through working condition analysis and calculation,which provides an analysis basis for the establishment of the comparison and selection process of subsequent foundation pit dewatering schemes.3.Taking the preliminary design and basic working conditions of the dewatering and drainage scheme of the deep foundation pit of huangtiandang gate weir as the analysis basis,three methods of fuzzy analytic hierarchy process,entropy weight analysis and grey correlation analysis are selected to analyze the applicability of their comparison and selection.Finally,the comparison and selection of fuzzy analytic hierarchy process is selected as one of the comparison and selection methods of dewatering and drainage of the project.At the same time,the value engineering theory is introduced,combined with the data processing advantages of analytic hierarchy process and entropy weight method,and the calculation of the function index of the selected scheme is improved.A new comparison is established by comparing the function coefficient and value coefficient,and then the comparison results with fuzzy analytic hierarchy process confirm each other.4.In view of the construction conditions and location characteristics of the dewatering and drainage of the deep foundation pit of huangtiandang gate weir,this paper explains the basic principles of the selection of comparison and selection indicators and the establishment of the index system.Combined with the configuration in the preliminary design,this paper analyzes and determines its various indicators and their evaluation factors,so as to establish the comparison and selection index system of dewatering and drainage schemes.5.According to the comparison and selection of dewatering and drainage schemes based on fuzzy analytic hierarchy process and value engineering analysis,the optimal dewatering and drainage scheme is selected.This study can also provide reference for the comparison and selection of dewatering and drainage schemes of subsequent similar projects,improve the construction organization of dewatering and drainage process and improve the overall benefits of dewatering and drainage process.