Optimization Of Supporting Schemes For Deep Foundation Pit Of Xi’an Subway

In this paper, based on Xi’an the fourth metro line Hou Cun station deepfoundation pit engineering as the research background, through the analysisof monitoring data, the regular of deformation of retaining structure and the settlementof surrounding was found.From the curve of retaining pile horizontal displacement andground settlement, the observation revealed that the observed maximum displacementof supporting pile and surface settlement was far less than the warning value, it is saidthat the supporting design is too conservative and there are optimal space.Using the FLAC3D finite element simulation method to analyses the deformationof foundation pit, it is found that although there are some differences, but have the sametrend by the comparison of simulated values and measured values, when the complexityof the construction site considered, the establishment of calculation model andparameters are reasonable.On the basis of the model validation, in order to study the effect of retaining piledepth, pile spacing, spacing and steel support axial force on the deformation offoundation pit, the division of the different situations were simulated, the regular of thedeformation of foundation pit effected by the pile embedded depth, diameter of pile andsteel support axial force, spacing was summed up. In order to make full use of the selfstability, reduce project cost, optimized the scheme of foundation pit supporting. Thenew supporting scheme analyzed and simulated by the FLAC3D finite element software,through analysis the curve of piles displacement and the surrounding surface settlementin the new support scheme, found that the maximum value were more than the value in the original scheme but not surpassed the specification of the warning value, it showedthat the new scheme of foundation pit is stable, safety and more economical reasonable.