摘要
高渗透大粒径砂卵石地层因孔隙率大、结构松散、水文条件复杂,在地下连续墙施工中易造成泥浆渗漏、成槽困难等问题,严重影响成槽精度与结构安全。以北京市某轨道交通2号盾构井工程为依托,针对地下连续墙穿越砂卵石与强风化白云岩交界带的复杂地质条件,提出并实施“旋挖引孔-抓斗成槽-冲击钻压密-双轮铣入岩-回灌砂浆封堵”的联合成槽施工技术。通过分段引导、局部加固与协同切削,实现了对复杂地层成槽全过程的可控施工。总结了施工工艺流程与质量控制要点,明确适配设备与泥浆护壁调控措施,并在现场实施中取得良好成效,为类似地质条件下地下连续墙工程提供了有力技术支撑与实践依据。
In strata characterized by high permeability and large-grain gravel,the loose structure,high porosity,and complex hydrogeological conditions often lead to severe slurry leakage and difficulties in trench excavation during diaphragm wall construction,which critically undermine excavation accuracy and structural integrity.This study,based on the diaphragm wall construction of the No.2 shield launching shaft in a subway project in Beijing,addresses the challenges posed by the gravel layer interfacing with strongly weathered dolomite.A combined trenching technique integrating rotary drilling pre-boring,grab bucket excavation,impact compaction,dual-wheel milling into bedrock,and pressure grouting backfill was proposed and implemented.The method achieves controlled excavation across complex strata through staged guidance,local reinforcement,and coordinated cutting.The construction workflow and quality control measures are systematically summarized,with specific focus on equipment selection and slurry stabilization strategies.Field application demonstrates that the technique effectively mitigates slurry loss and ensures trenching precision,offering valuable technical support and practical reference for diaphragm wall construction in similarly challenging geological conditions.
作者
桑松
SANG Song(BCEG Civil Engineering Co.,Ltd.,100015,Beijing,China)
出处
《建筑技术》
2025年第24期2980-2983,共4页
Architecture Technology
关键词
轨道交通
地下连续墙
高渗透砂卵石地层
漏浆处理
成槽施工
urban rail transit
diaphragm wall
high-permeability gravel layer
slurry loss control
trench excavation construction
