Study On Comparison Of Mechanical Transformation Mechanism Caused By Side Drifts-support Method And By Central Drifts-column Method For Large Flattened Cross-section Subway Station

To reduce the influence of the surface settlement and deformation of the buildings and the underground facilities caused by the subway station construction, that has a large flattened cross-section, it has to evaluate the contingent surface settlement and deformation correctly and help us to choose the better construction approach.Both of the side drifts-support method and the central drifts-column method are the construction approach to construct the single-level section with two columns and three spans. But which one chooses to be design and make it in practical usage always causes an argument. So, in this paper, based on the ZhangZizhong subway station of Line 5 and its monitoring data, I compare the side drifts-support method and the central drifts-column method in the same geology parameters and the same structure form by finite difference element analysis software FLAC^3D. And then, I conclude that the side drifts-support method is better than central drifts-column method in mechanical transformation mechanism and construction environment and price. Because soil disturbance caused by the side drifts-support method is too much, especially in the middle holes excavation time, the settlement is larger. Base on the monitoring method, if the ground floor is substantial or its location is not an important zone, we would better choose side drifts-support method, on the contrary, we would better choose central drifts-column support method. If choose the side drifts-support method, the soil in the middle of the section must be reinforced.