高强度花岗岩中大直径钻孔灌注桩施工技术.pdf

施工技术 2014年1月上 26 CONSTRUCTION TECHNOLOGY 第43卷第1期 D0I:10.7672/sgj82014010026 高强度花岗岩中大直径钻孔灌注桩施工技术* 陈飞 (江西理工大学资源与环境工程学院，江西州341000) [摘要]宁德吉屿大桥钻孔灌注桩桩径2.2m、桩深86m 桩端持力层进人强度高达138MPa的弱风化花岗岩3m 经 过多种施工方案的分析比较，采用回转与冲击组合钻进工艺，满足了工程质量和进度要求，节省造价12万元，缩 短了工期.详细介绍了回转、冲击钻进施工工艺和技术措施，对施工中存在的问题及处理措施进行了总结. [关键词]桥梁工程；桩基础；花岗岩；钻孔灌注桩；施工技术 [中图分类号]TU753.3 [文献标识码]A [文章编号]1002-8498(2014)01-0026-03 Construction Technology of Large-diameter Bored Piles in High Strength Granite Chen Fei (Faculty of Resource and Environmental Engineering Jiangxi University of Science and Technology Ganzhou Jiangxi 341000 China) Abstract:The bored pile diameter of Ningde Jiyu bridge is 2.2m and the depth of pile is 86m.The bearing layer of pile end drilled in slightly weathered zone granite with 138 MPa strength and 3m depth. According to the analysis and parison of different construction schemes rotary drilling and percussion drilling were adopted which can meet the requirement of construction quality and progress.This paper introduced construction and technical measures of rotary drilling and percussion drilling in detail and summarized the problems in construction and its treatment measures. Key words:bridges;piles;granite;bored piles;construction 1工程概况 630kPa;⑥强风化花岗岩厚16.1~20.3m 9= 福建宁德吉屿大桥全长2162m 设计为双向645kPa 9.=720kPa;⑦弱风化花岗岩厚26m 主要 车道，桥墩采用柱式墩，桩基采用灌注桩基础，其中矿物为白云母、黑云母、钾长石等，节理裂隙不发 2 3号主墩基础共有2.2m钻孔灌注柱40根，桩长 育，岩心坚硬、致密，基岩强度很高，其最低强度 86m 设计承载力极限值为28000kN 桩基持力层进 Rm=65MPa 最高强度R=138MPa 桩尖进入弱 入弱风化花岗岩3m. 风化花岗岩3m. 2工程地质条件 3施工难点及成孔工艺优化选...