Finite Element Analysis Of The Structure Of The Snchor Support Structure Of Deep Foundation Pit In Hefei Square

With the prosperity of the economy all over the world,the development of construction projects has been given a strong economic guarantee.As a result,the difficulty and scale of the project are also constantly expanding,such as the urban landscape engineering,high-rise buildings,underground engineering and large-scale underground space are constantly emerging,especially the utilization of underground space is becoming more and more common,which makes for the construction of the underground space becomes the key solution.The most basic of underground construction technology is deep foundation pit engineering,so it is necessary to pay attention to the construction technology of deep foundation pit.In recent decades,the development of urban foundation pit engineering has become more and more rapid.In order to solve the tight urban plots and expensive land prices,the development and utilization of urban underground space will be the best solution.With the utilization of underground space has become more and more frequent,also caused safety problems and foundation pit engineering accidents is increasing,seriously affected the social stability and development,so the foundation pit is an important object of the present study in the world.Pile anchor support is a relatively mature technique in foundation pit support technology.Although it has rich practical experience,its basic theory and design method still have many shortcomings.This paper made a deep understanding of the basic theory and design calculation of Pile anchor support structure and research which a detailed survey of the combination of Hefei Hengda central square 4#block project,using ABAQUS finite element software based on the numerical simulation scheme of pile anchor supporting structure.(1)First of all,a preliminary understanding of the structure,deformation characteristics and working mechanism of the pile anchor composite support structure is carried out through the literature.Then,the three methods of internal force calculation of pile anchor combined support are briefly introduced.Finally,through an example of general situation and geological conditions of the project in Hefei Hengda central square 4#block project,understand the design and calculation of pile anchor supporting structure,the analysis provides a theoretical basis for the deformation of supporting structure for further simulation software.(2)On the north side of foundation pit 5-5 section combined pile anchor supporting structure as an example,using the ABAQUS finite element numerical simulation analysis software to establish numerical calculation model of foundation pit,the pile anchor retaining structure are analyzed with numerical simulation calculation result shows that the horizontal displacement of retaining structure,vertical displacement,bottom heave and anchor force.(3)Under the control of the axial tension of the anchor rod,the horizontal displacement of the top of the pile is parabola,and the horizontal displacement at the top of the pile decreases first,then increases,and finally decreases gradually.Early without additional support of anchor pit excavation,the maximum horizontal displacement at the lateral supporting pile top;with the excavation and anchor pit added later,the maximum horizontal displacement gradually to the lower part of support pile move;when the excavation to the design elevation,horizontal displacement is zero.The vertical displacement of the retaining pile body and gradually increased with the increase of excavation depth,the basic linear linear distribution,deeper excavation,the vertical displacement of the retaining pile body increases gradually,when the excavation to the design elevation,the maximum vertical displacement of supporting pile.In the condition of excavation,the pit bottom uplift curve is relatively flat,with the increase of excavation depth,soil uplift amount increases rapidly;when the pile anchor retaining structure complete,in the limit of support pile and anchor,soil heave decreases rapidly,reaching a steady state of foundation pit.The excavation condition of anchor force situation is roughly the same,which is the anchoring section of the bottom to the top of the free gradually increases from top layer to bottom layer increases,the minimum axial force is at the bottom of the anchor section,and the maximum axial force is at the top of the free end.This article through to the Hefei of a deep foundation pit supporting structure design and numerical simulation can provide practical experience and theoretical basis for the design and construction of similar deep excavation engineering in Hefei area,the project has a certain reference value.