ANALYSIS OF RETAINING STRUCTURES FOR DEEP FOUNDATION PIT OF QIUTAO ROAD STATION IN HANGZHOU METRO

The retaining structure deformation of the deep foundation pit is an important factor for the effect on the deformation of deep foundation pit. In view of the retaining structure of deep foundation pit for Qiutao Road Station in Hangzhou Metro,the finite element method of elastic foundation beam bar system is adopted. Firstly, the computation analysis to the standard section as a project example of the deep foundation pit is carried out through the contrastive analysis of the computed results and measured data,and then the computation model and the computation method are confirmed. Finally,in view of the silty sand soil stratum of the Qiutao Road Station, the rigidity of the retaining structure,the order of the excavating and the supporting of the deep foundation pit,the arrangement mode of the supports,and the improvement soils depth and other design and construction factors on effect of the deformation and internal force of the retaining structure are all discussed. The analytical results indicates that the pile intensity satisfies the requirements,usually it is not suitable through increasing the pile rigidity to reduce the deformation of the retaining structure. For the multi-support arrangement,the way that the supports are dense in the excavation upside and the supports are sparse in the excavation lower part is optimized. In the construction,the first supporting and then excavating excavation way should be adopted. There is a critical depth for the improvement soils. The appraisal analysis to each influencing factor is adopted to provide the reference to the related design and the construction.