硬质地层条件下大直径桩基旋挖钻成孔工艺适用性研究  

Research on Applicability of Rotary Drilling Technology for Large Diameter Pile Foundation in Hard Stratum

作　　者：张志伟 ZHANG Zhiwei(CHINA MCC5 GROUP CORP.Ltd.,Chengdu Sichuan 610063)

机构地区：[1]中国五冶集团有限公司,四川成都610063

出　　处：《智能建筑与工程机械》2021年第11期3-7,共5页Intelligent Building and Construction Machinery

摘　　要：旋挖桩以环保、高效、成本低、自动化程度高等独特优势在交通行业与建筑行业中得到了广泛应用,然而在中风化、微风化基岩等硬质地层中,由于地层岩体天然强度较高,旋挖钻机施工就比较困难。本文以四川某桥梁主墩桩基础为载体,探索大直径旋挖桩在硬质地层条件下的适用性,结果表明,通过二次成孔局部取芯法干作业成孔大直径旋挖桩在硬质地层条件下是适用的,该技术适用于中风化、微风化岩层等硬质地层条件下直径大于800 mm的旋挖桩成孔,尤其适用于旋挖钻机功率不足或者钻杆扭矩超过额定扭矩的情况,同时对于较致密的卵砾石、孤石地层旋挖桩成孔施工也有很强的借鉴和指导意义。Rotary digging pile has been widely used in transportation industry and construction industry due to its unique advantages of environmental protection,high efficiency,low cost and high degree of automation.However,the construction of rotary drilling rig is difficult due to the high natural strength of strata rock mass in hard strata such as moderately weathered and slightly weathered bedrock.The text researches the applicability of large diameter rotary digging pile in hard stratum.The results showed,the large-diameter rotary drilling pile with hole-forming by secondary hole-forming and local coring method is applicable in hard stratum.This technology is suitable for the hole-forming of rotary drilling pile with diameter greater than 800 mm in hard stratum such as medium-weathered and slightly-weathered strata.It is especially suitable for the case of insufficient power of rotary drilling rig or the torque of drill pipe exceeding the rated torque.At the same time,it also has a strong reference and guiding significance for the hole-forming construction of rotary drilling pile in dense gravel and boulder stratum.

关 键 词：硬质地层 大直径桩 旋挖桩 局部取芯法 

分 类 号：U445.551[建筑科学—桥梁与隧道工程]