【摘要】 昆明市综合交通国际枢纽建设项目基坑工程面临支撑拆除工程量巨大、七圆环支撑耦合受力转换复杂、周边环境变形控制要求高、开挖范围存在多层泥炭质土等难题。为保证基坑内支撑的快速安全拆除，以“两纵两横”为主要传力骨架，提出“先次后主”的内支撑拆除原则，采用“原路撤退、对称拆除”的拆除顺序。采用“绳锯切割”拆除工艺。第2,3道支撑采用分区分块拆除方式，首道支撑采用“扫除枝叶，保留骨干”的拆除方式。采用位移敏感区钢斜撑换撑技术、切割块水平转运的楼盖协同承载技术、BIM辅助绳锯切割点布置技术3种辅助施工技术。通过以上技术实现了软弱泥炭土超大规模深基坑对紧邻地铁影响的毫米级变形控制。更多还原

【Abstract】 The foundation excavation project of Kunming comprehensive transportation international hub construction project is faced with the problems of huge amount of support demolition, complex coupling force conversion of seven-ring support, high control requirements of surrounding environmental deformation, and multi-layer peaty soil in excavation range. In order to ensure the rapid and safe demolition of the internal support of the foundation excavation, the“two vertical and two horizontal”is taken as the main force transfer skeleton, and the principle of “secondary and then primary”internal support demolition is proposed. The demolition sequence of “original road retreat and symmetrical demolition” is adopted. The “wire saw cutting”demolition process was adopted. The 2nd and 3rd supports were dismantled in different blocks, and the first support was dismantled by“removing branches and leaves and retaining backbone”. Three kinds of auxiliary construction technologies are adopted, including steel brace replacement technology in displacement sensitive area, floor cooperative bearing technology of horizontal transfer of cutting block, and BIM auxiliary wire saw cutting point arrangement technology. Through the above technology, the millimeter-scale deformation control of the influence of the super-large-scale deep foundation excavation of soft peat soil on the adjacent subway is realized.更多还原