Deformation and Force Analysis of a Pit-in-pit Support Structure with Upper Support and Lower Anchor
ZHAO Ping1, NING Xiaoqing1, WANG Jianwang2, YAN Zihai3
1. Xi′an University of Architecture and Technology, Xi′an, Shaanxi 710055, China; 2. South China University of Technology, Guangzhou, Guangdong 510630, China; 3. Power China Huadong Engineering Corporation Limited, Hangzhou, Zhejiang 311122, China
Abstract：Research purposes: In order to study the deformation and force characteristics of the support structure of the upper braced and lower anchored pit-in-pit, the excavation process of the pit-in-pit at Yiwu International Trade City Station was numerically simulated by means of a finite element model, while the later field measurement data verified the results of the preliminary analysis. Research conclusions: (1) During the excavation of the pit-in-pit with upper support and lower anchor, the horizontal displacement of the soil on the outer side of the enclosure pile finally shows a combination of "cantilevered" and "bulging" changes. The influence of excavation in the pit on the outer pit retaining pile the outer soil deformation is small, but the influence on the deformation of the soil on both sides of the inner pit is large; the overall change of the settlement value of the soil on both sides of the pit conforms to the change form of "parabolic type"; the deformation of the base elevation is centred on the middle point of the outer pit and spreads around, and the amount of base elevation becomes smaller and smaller, and the excavation of the inner pit does not affect the development pattern of the amount of base elevation. (2) During the excavation of the pit, the overall change of the internal force of the two concrete supports is similar, the first concrete support is under the greatest force, and the maximum anchor cable tension occurs at the second anchor cable, the excavation of the inner pit will reduce the internal force of the four supports of the outer pit to a certain extent. (3) The research results can provide reference for the design of the support structure and construction plan of similar pits.
赵平, 宁啸青, 王建望, 闫自海. 上撑下锚坑中坑支护结构的变形与受力分析[J]. 铁道工程学报, 2022, 39(3): 1-6.
ZHAO Ping, NING Xiaoqing, WANG Jianwang, YAN Zihai. Deformation and Force Analysis of a Pit-in-pit Support Structure with Upper Support and Lower Anchor. Journal of Railway Engineering Society, 2022, 39(3): 1-6.
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2022, Vol. 39 
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