Comparison Of (Single)Double-row Pile-anchor Support Schemes For Deep Foundation Pits And Numerical Simulation Optimization Analysis

With the advancement of urban development,skyscrapers are setting new height records and excavation projects are developing more and more.As a result,the difficulty of excavation support technology has increased and presented new design and construction challenges.How to ensure the overall stability of the foundation pit and reduce the loss of structures and municipal facilities during the excavation process,highlights the importance in the selection of supporting schemes.When the pile struct.is limited to technical applications,the double pile anchor struct.with its lateral stiffness and the main characteristics such as palisade depth is larger,has been widely used in real engineering.Due to the complexity of the basic engineering of the foot,the theoretical and design calculations are not perfect enough compared to the anchor struct.of the file.In this thesis,combined with actual engineering projects,with reference to factors such as ground conditions and surrounding conditions,the finite element software is used to analyze the mechanical performance and displacement of the double-row pile-anchor supporting structure.The main research work is as follows:(1)First,the current status of domestic and foreign research on underground pit protection,double row pile protection and pile anchor support is classified,and the application fields of excavation protection and cutting force and displacement calculation methods are summarized.(2)In accordance with the regulations and related theory,combined with the foundation pit surrounding environment,Preselected single pile anchor and double row pile anchor two support methods,the reason for using it is the excavation software,which is deeper than the basic principle.in the cross section of the foundation pit DE support scheme determined according to the result of double row pile anchor support form work.(3)The MIDAS GTS NX software has been selected and combines the actual engineering situation with all parameters,select a suitable constitutive model,Create a3 D model of the DE section of the excavation,simulate the excavation process,Analyze the displacement law of the soil during the excavation process,and the internal force and deformation of the double-row pile-anchor support scheme.(4)Use MIDAS GTS NX software to simulate influencing factors of prestress,pile diameter,pile pitch,row pitch,and anchor rope tilt angle to analyze internal force displacements and changes.It is then optimized by orthogonal experiments to analyze the importance of each factor to variability.Orthogonal experiments have shown that the importance of column spacing and anchor cable angle affects the important minimum of the index.