| With the development of urban rail transit, the underground space and the super high-rise building projects increasing, deep foundation pit engineering is more frequent, and the diaphragm wall and supporting of reinforced concrete brace system is a new method for deep foundation pit supporting.Taking a project of supporting structure of a certain diaphragm wall and reinforced concrete supporting of Nanning as an example, the paper uses Midas GTS to carry out numerical analysis. On the basis of verifying the feasibility of supporting schemes from the largest strut axial forces, the maximum deformation of diaphragm wall and the maximum settlement of ground these three aspects,the paper respectively analyzes the strut axial forces of the cross supporting, longitudinal supporting and corner supporting along with the dynamic changes of the construction phases(load), and concludes the rule of the dynamic changes of the strut axial forces.Aiming at the scale of the foundation pit being large and the long construction period, the paper researches the influence of temperature function on the supporting performance, including heating and cooling, and research the dynamic changes of the supporting axial force and the deformation law of the diaphragm wall from different temperature difference, the way of temperature changes and the difference of temperature between supportings.It’s proved the influence of temperature function on the supporting axial force and the deformation law of the diaphragm wall is significant.The article also researches the stability of the support, derive the calculation formula of the bending moment and the flexural equation of the supporting under the common effect of supporting gravity, axial pressure and post lifting.By calculation,it shows that when the displacement of post lifting is 0.030m,bending moment caused by post lifting can be accounted for 82.91% of the total bending moment in the supporting across and the results show that the influence of post lifting on total bending moment in the supporting across is remarkable.What’s more,the calculation formula derived by shows that width of the foundation pit and total bending moment in the supporting across has close relation, thus the article also analyzed the relation of width of the foundation pit, the bending moment in the supporting across caused by post lifting with the ratio of the total bending moment in the supporting across and the bending moment in the supporting across caused by the supporting gravity with the ratio of the total bending moment in the supporting across. |
