Research On Numerical Simulation Of Construction Process And Construction Optimization Of Deep Base Pit By The Construction Technology Of Top-down Method In Geotechnical Area

With the rapid development of economy and urbanization,the development of underground space for high-rise and super-tall buildings is particularly important,and the construction technology of top-down method has been widely applied as an effective method for underground space construction.Therefore,the research on the construction technology of top-down method in geotechnical areas is active.significance.Based on the second phase medical building project of Hunan Wangwang Hospital,this paper mainly uses the numerical simulation combined with the on-site monitoring method to complete the following work:(1)The paper research the deformation of underground continuous wall,the differential settlement between the wall column and the column and column,the uplift of soil at the bottom of the pit are studied,settlement of soil outside the pit and variation of internal force of structure under various working conditions,Drawing the following conclusions:The maximum horizontal displacement of the diaphragm wall does not occur in the position of the wall body as in the soft soil area,but on the top of the wall,which is related to the setting of the reverse boundary layer and the condition of soil quality.The differential settlement between the wall column and the column and column becomes larger and larger with the construction,and the construction of the basement beam and slab is more beneficial to the control of the differential settlement.The maximum value occurs at the boundary between the main building and the skirt building,and the maximum value of the soil uplift at the bottom occurs at the completion of the excavation on the negative first floor time pit surface settlement "Groove shape.The maximum value occurs at the edge of the pit 4m position department.The axial force of the column increases with the construction,and the axial force of the middle column is greater than that of the side column.When selecting the number of upper construction floors,the settlement and bearing capacity of the columns are mainly considered in the construction technology of top-down method,which can be referred to for other indexes.(2)By optimizing the construction pian of inverse construction in geotechnical area.It is found that the construction plan of soft soil area with the first layer as the inverse boundary point is not suitable for geotechnical area.Hunan Wangwang Hospital Phase ? Medical Building Construction Project with the negative first floor as the inverse demarcation Point,although it is more economical than the first floor as the inverse boundary point,However,it tends to be conservative compared with the construction scheme with negative second floor as the inverse boundary point.(3)By optimizing the construction parameters of underground continuous wall in geotechnical.It is concluded that if the underground continuous wall does not bear the superstructure load,it can make full use of the embedded action of rock.It is feasible to reduce the embedded depth and thickness of the diaphragm wall reasonably.