The Deformation Monitoring And Numerical Simulation Analysis Of A Pile Anchor Support Deep Foundation Pit In Lanzhou Area

As the hidden engineering of buildings,foundation pit engineering is not only the key part of building construction,but also the key content to be solved in engineering construction.At the same time,the effective support of foundation pit plays a decisive role in the smooth excavation.As the temporary building structure system of building construction,foundation pit support has short life cycle and relatively low safety reserve requirements,so it has great risk.In the dynamic process of foundation pit excavation,it is necessary to strictly control the deformation.In this paper,taking a deep foundation pit project in Lanzhou as an example,the deep foundation pit engineering in which the excavation depth is relatively deep and the soil in the foundation pit depth is plain fill is mainly studied as follows:(1)The pile anchor supporting structure used in the north side of the foundation pit is designed by using the software 7.5 of the deep foundation pit,the distribution of shear force,displacement and bending moment of the pile is obtained,and the overall stability,overturning resistance and uplift resistance of the foundation pit are checked and calculated in order to verify the reliability of the design of the supporting structure.(2)In the process of foundation pit excavation,the monitoring points are arranged around the foundation pit,the monitoring data of each monitoring point is recorded,and the deformation of the soil at each point is grasped in real time,so as to carry out deformation analysis.(3)The numerical simulation analysis of the pile anchor support structure section of the foundation pit is carried out by the Plaxis finite element analysis software,The deformation law of the foundation pit and the internal force of the support structure are grasped.(4)The simulation results and monitoring results are compared and analyzed to verify the applicability of the support scheme,the guidance of numerical simulation calculation and the importance of monitoring.(5)The comparative simulation analysis takes the soil in the excavation depth of the foundation pit as an example to analyze the impact of soil adhesion force and internal friction angle on the safety of the foundation pit,and analyzes the use of different Anchorage length,Anchorage tilt angle and Anchorage force.Law of internal force of support structure and its influence on the safety of foundation pit.Through the field monitoring,numerical simulation analysis and comparative analysis of this practical engineering example,the feasibility of the numerical method and the reasonable effectiveness of the numerical simulation results in this paper are illustrated.