Finite Element Analysis And Practical Application Of Top-down Method Construction Process Supporting Points

Based on the lag and specificity of construction theory and technology aboutTop-down method. The domestic still lack of a set of comprehensive design andconstruction of the theory about Top-down method. In this paper, the west town ofXiangtan business district underground-defense works engineering were researchedas background, construction technology, key node processing and other related issueswere discussed at the process of Top-down method, which tried to form a completeengineering methods about Top-down method. At the same time, relation to Xiangtangeological conditions, use the engineering as background,researched the relationshipbetween main structural support system and Soil step-by-step unloading at the case ofRoof in the soil cover and the restoration of road traffic, Verified the rationality andfeasibility of using finite element analysis by actual monitoring data．The conclusionare as follows:1.The largest vertical displacement is t the area of contact Structure of the sidespans and earthwork; while the support columns subject and column caps joints is thethe minimum of overall displacement.2.Each column bears the load is not evenly distributed at the process of unloading,the maximum stress generally appear in the column and square step at the bottom ofthe soil, which distributed the contact area of the lower part of the supportcolumn and cap joints.3.The stress and strain of the support columns along with the earth excavationgradually increased, And the same with remaining excavation of earth stress andstrain.4.Deformation has been the main settlement， Occasional uplift, but nosignificant.The final settlement value of the final settlement value is less than theside column and the intermediate support columns.5.Settlement Found of support column was an average of more1mm than analogvalue, But the overall trends were the same,gradually increased.