坑中坑开挖快速封闭施工技术应用研究  

Research on the Application of Rapid Closure Construction Technology in Pit Excavation

作　　者：关文达 邢东杰 关丽娟 刘恕全 GUAN Wen-da;XING Dong-jie;GUAN Li-juan;LIU Shu-quan(Guangzhou Municipal Dunjian Construction Co.,Ltd.,Guangzhou 511442;China Tunnel Construction Group Co.,Ltd.Guangdong,Guangzhou 510000)

机构地区：[1]广州市盾建建设有限公司,广州511442 [2]广东华隧建设集团股份有限公司,广州510000

出　　处：《广州建筑》2024年第6期50-53,共4页GUANGZHOU ARCHITECTURE

摘　　要：因珠三角地区潮湿多雨的气候特点,地下明挖基坑施工长期以来是困扰广州地铁施工的难题。为了解决深基坑基底坑中坑开挖后未及时封闭受雨水冲刷以及地下水浸泡而造成失稳、滑坡的问题,本文根据应用场景实际情况,创新性地提出了砂质黏性土层开挖坑中坑过程中快速封闭施工技术。本方法根据坑中坑主体结构尺寸要求,在地面分块预制U型槽构件,待基底坑中坑开挖完成后,将预制U型槽构件吊装至坑中坑快速封闭基底,以取代原有现浇垫层或砌筑挡土墙的工艺。经实践研究表明:快速封闭技术避免了对地基的反复扰动,减少了坑中坑土体长期暴露带来的安全风险和质量控制风险,以此解决因基坑开挖后未能及时封闭基底而造成坑中坑侧面土层失稳和滑坡的风险。本研究成果可为类似不良地质基坑施工提供参考。Due to the wet and rainy climate of the Pearl River Delta region,constructing open-pit underground works has long been a challenge in the construction of the Guangzhou Metro.To address the issue of the pit in deep foundation excavations not being closed promptly after excavation,leading to washing by rain and soaking by groundwater,which can cause instability and landslides,this research innovatively proposes rapid sealing construction technology for the excavation of pits in sandy viscous soil layers,tailored to the specific application scenarios.In this method,U-shaped groove members,prefabricated in blocks on the ground according to the size requirements of the pit's main structure,are hoisted to the quick-sealing base within the pit,replacing the original cast-in-place cushion or masonry retaining wall process.The practical research shows that rapid closure technology avoids repeated disturbances to the foundation and reduces safety and quality control risks associated with the long-term exposure of soil in the pit,thereby mitigating the risk of soil instability and landslides on the pit's sides due to the failure to seal the foundation promptly after excavation.The research findings can provide valuable insights for similar construction projects in challenging geological conditions.

关 键 词：砂质黏性土层 坑中坑 预制件 快速封闭施工 

分 类 号：TU753[建筑科学—建筑技术科学]