Research On Monitoring And Deformation Monitoring Of A Super-high-rise Deep Foundation Pit In Yinchuan

Based on a super high-rise foundation pit project in Yinchuan City,this paper makes a preliminary understanding of the support method,deformation mechanism and foundation pit deformation monitoring and calculation theory of deep foundation pit engineering by consulting a large amount of literature materials.The method of excavation and support of deep foundation pits and the layout of monitoring schemes,combined with the measured data of foundation pit support deformation,analyzes the support effect and deformation law,mainly carried out the following research:(1)According to the geological conditions of the site,comprehensively compare different types of support,select the foundation pit support scheme of row pile+anchor cable and carry out design calculation.Based on the analytical calculation theory of the mountain shoulder male method,the internal force of the foundation pit support structure is calculated,and the anti-overturning and anti-lifting stability of the foundation pit are checked to determine whether the foundation pit excavation and support scheme meet the stability requirements.(2)The inner force calculation of the foundation pit support system is carried out by using the rational deep foundation pit software F-SPW7.0.The results of the internal force calculation of the comparison elastic method and the mountain state male method show that the stability requirements of the foundation pit can meet the relevant specifications.The limit value,the basic assumption of the male shoulder method,the description of the axial internal force of the anchor(cable)and the deformation of the foundation pit can be matched to the working state and performance of the support structure of the yellow soil foundation in Yinchuan.(2)Using ABAQUS finite element simulation software,the numerical model of excavation and support of deep foundation pit is established and simulated.The internal force variation law and deformation of foundation pit support structure are analyzed.The results show that the numerical simulation results and the change trend of the axial force of the anchor(cable)are consistent with the calculation results in the previous paper,but the axial force level of the numerical simulation results is generally smaller than that of the mountain shoulder.(3)Formulate the base pit deformation monitoring plan and implement the monitoring points to carry out the foundation pit support monitoring under different working conditions,analyze the horizontal deformation of the pit wall and the settlement of the pit top during the excavation of the foundation pit,and carry out the surrounding road environment.Monitoring,comparing the internal force monitoring results of the supporting structure with the numerical simulation,exploring the deformation law and supporting effect of the foundation pit,verifying the rationality of the calculation theory of the male shoulder method of Shanshanbang,and the relevant conclusions have certain certainity for the loess foundation pit engineering in Yinchuan area.Practical guiding significance.