The pit-in-pit foundation of Beijing High Speed Railway Chaoyang Station presents the characteristics of limited construction space and varying depths of the pit, and the conventional solution of dismantling and replacing bracing makes the processes interfere with each other causing the construction period to be unsatisfactory. From the perspective of simplifying the construction process of deep foundation pit support replacement, based on the concept of ‘support replacement method', a combined support scheme of full support and steel oblique support was proposed. Numerical simulations were used to study the original bracing replacement scheme (steel inverted bracing), the sidewall replacement bracing scheme and the full hall bracing combination scheme, and the feasibility of this thesis scheme was verified through on-site monitoring. The following conclusions were reached: (1) the full hall bracing scheme reduces the construction steps, saves the construction budget, ensures structural safety during construction and is successfully applied to the construction of foundation pit demolition and replacement bracing in shaped pits; (2) the maximum deformation of the ground connection wall increases by only 9% compared with the original demolition and replacement bracing scheme for the full hall bracing scheme, while the horizontal deformation increases by 35% compared with the full hall bracing scheme for the sidewall only scheme; (3) The constraint effect of the built side wall and the connection part of the frame body makes the overall deformation of the frame body small, and the internal force of the scaffold shows a trend of large in the middle and small on both sides.
Cui Xiangyang
,
Wang Jiahao
,
Li Zhaoping
,
Liu Teng
,
Lü Jinbiao
. Study on the Selection of Support Replacement Scheme and Deformation Control of the Main Structure of the Special-Shaped Pit in Pit[J]. Chinese Journal of Underground Space and Engineering, 2024
, 20(S1)
: 273
-282
.
DOI: 10.20174/j.JUSE.2024.S1.33
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