摘要
为解决在低净空内实现大直径MJS垂直桩的施工精度与质量控制难题,针对该工法在珠三角城际轨道交通新白广机场T1—T2区间盾构下穿机场地下通道工程中的应用,开展施工技术研究。首先根据项目概况与地质条件,制定本次下穿方案与土体预加固作业安排。然后,针对本工程中的MJS施工难点,对关键控制技术进行研究。最后,分别从成桩质量、结构位移、效益评价3方面综合分析其加固效果。研究结果表明:1)通过改造吊物装置系统,可在低净空内实现加固作业,极大地提高施工适应性;2)采用特制的合金钻头与主机水准仪可实现高精度成孔,且使用高压注浆系统可实现大直径优质桩体;3)改进后的MJS工艺既保证了加固效果,又可有效规避地下障碍物及管线,其微扰动效果也确保了施工期间机场地下通道结构的正常通行。
To improve the construction accuracy and quality of large-diameter metro jet system(MJS)vertical reinforcement under a low clearance,a case study is conducted on the Airport T1~T2 Section on the Xintang-Baiyun Airport-Guangzhou North Railway Station of Intercity Railway in Pearl River Delta,and construction technologies are introduced.First,according to the project overview and geological conditions,the under-crossing scheme and the soil pre-reinforcement arrangement are determined.Then,the construction challenges and essential construction control technologies are studied specifically.Finally,the reinforcement effect is comprehensively examined from three aspects:pile-forming quality,structural displacement,and benefits evaluation.The research results show the following:(1)By transforming the lifting device system,the reinforcement construction can be realized under low clearance,thus greatly improves the construction adaptability.(2)The specially-designed alloy drill head and the level can realize pore-forming with high precision,and the high-pressure grouting system can realize the high-quality pile with large diameter.(3)The improved MJS process not only ensures the reinforcement effect,but also effectively avoids underground obstacles and pipelines, and its micro-disturbance effect also ensures the normal operation of the underground passage duringconstruction.
作者
吕明豪
韦成林
唐欣薇
LYU Minghao;WEI Chenglin;TANG Xinwei(China Tunnel Construction Group Co.,Ltd.,Guangdong,Guangzhou 510228,Guangdong,China;South China University of Technology,Guangzhou 510640,Guangdong,China)
出处
《隧道建设（中英文）》
CSCD
北大核心
2023年第S01期434-442,共9页
Tunnel Construction
关键词
盾构下穿
低净空
MJS垂直加固
成桩精度
微扰动
设备改造
shield under-crossing
low clearance
metro jet system vertical reinforcement
pile-forming precision
microdisturbance
equipment modification
