超厚砂层超深埋深大孔径钻孔灌注桩施工技术研究

Study on the Construction Technology of Super-thick Sand Layer, Ultra-deep Buried and Large-bore Bored Cast-in-place Pile

目前,超深埋深大孔径钻孔灌注桩因承载力大、可在原土面施工、能够满足单桩单柱的需要而得到推广应用。但在冲积形成地层中,由于超厚砂层的存在,超深埋深大孔径钻孔灌注桩的成桩质量难以得到保证。本文通过改进的成孔施工技术、特制优质泥浆调配和泥浆循环沉淀清渣系统技术、灌注桩钢筋笼上浮监测技术等方面的研究为超厚砂层超深埋深大孔径钻孔灌注桩施工提供技术指导。

At present,due to the large bearing capacity of the super-deep buried and large-bore bored cast-in-place pile,it can be constructed on the original soil surface and can meet the needs of single pile and single column,so it has been popularized and applied.However,in alluvial formation,due to the existence of ultra-thick sand layer,it is difficult to guarantee the quality of bored piles.This paper provides technical guidance for the construction of cast-in-place piles with ultra-thick sand layers,ultra-deep buried and large-diameter holes through the study of improved hole forming construction technology,special high-quality mud preparation,mud circulating and sedimentation slagging system technology,and floating monitoring technology of reinforcement cage of cast-in-place piles.