低净空钻机降高正循环成孔灌注桩施工技术研究

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中图分类号：TU753.3 文献标识码：A文章编号：1672-3791（2026）03-0132-05

Research on Positive Circulation Bored Pile Construction Technologyfor in the Low-Clearance Environment Drilling Rig Lowering

SHI LeiYANGBaofeng ZHAN Shiwei

Zhejiang Zhongnan Construction Group Co.，Ltd.， Hangzhou， Zhejiang Province， 31Oo2o China Abstract： This article proposes a systematic innovative technology based on the North Road Station project of Hangzhou Metro Line 12 toaddress the challenges of limited drilling rig height，low precision of steel cage docking，and dificult controlofconcrete pouring quality in pile foundation construction inlow clearance environments （clearance≤6m）.By developing a foldable lowering drilling rig （integrating hydraulic support rodsand sliding tracks），a steel cage segmented extension tool （spring positioning mechanism ±15 mm error compensation），a lower hanging guide frame （adaptive roller verticality ⩽0.5% ），a modular gantry lifting system （ ±10mm positioning accuracy），and a low clearance grouting frame （hydraulic lifting platform burial depth control of 2-6m ），a lowclearance pilefoundationconstruction integrated technology system has been formed.Engineering practicehas shown that this technology reduces the deviation of hole verticality to ⩽1% ，improves the efficiency of steel cage docking by 60% ，and increases the proportion of Class I piles to ⩾95% . It solves the problems of low effciency，high safety hazards，and unstable pilequalityof traditional processs inconfined spaces，and provides reliable technical support for the development of urban underground spaces.

Keywords： Low clearance; Driling rig lowering; Cast-in-place pile; Construction technology

钻孔灌注桩因具有较好的承载特性，而被广泛应用于桥梁桩基[1]。（剩余3827字）