摘要
针对沾临高速引黄济青干渠大桥面临的大直径超长桩经济性差、深厚砂性土塌孔风险高、跨渠空间受限等技术问题,该文在比选常规钻孔灌注桩、桩端桩侧组合后压浆方案基础上,最终提出并设计了行业最大盘径(4.5 m)和单桩体量最大(456 m3)的扩盘类桩基础形式,同时研发了三臂旋切钻头、长臂井径仪等配套装置,攻克了固结体施工、盘腔扩孔施工等质量控制关键技术。研究结果表明:通过研发多种施工机具并应用创新成果,固结扩盘桩得以顺利施工,桩身混凝土完整性检测为I类桩,自平衡承载力测试结果均符合设计要求,相比常规钻孔灌注桩,该技术可节省钢筋37.4%,混凝土57.7%,而且单桩承载能力提升33.9%,有效规避了深厚砂性土塌孔风险,固结扩盘桩技术具有显著的经济效益、社会效益和环境效益。
This article aims to address the poor economic efficiency of large-diameter and ultra-long piles,the high risk of hole collapse in thick sandy soil,and the limited space across the canal faced by the Bridge over Yellow River Diversion to Qindao Canal on Zhanhua‒Linyi Expressway.According to the comparison of conventional drilled cast-in-place piles with combined pile-end and pile-side post-grouting,the industry’s under-reamed drilled shaft foundation with the largest disc diameter(4.5 m)and the largest single-pile volume(456 m3)was proposed and designed.At the same time,supporting devices such as three-arm rotary cutting drill bits and long arm borehole diameter meters were developed,and key quality control technologies such as consolidation body construction and disc cavity reaming construction were tackled.The research results show that with the development and innovative application of various construction equipment,the construction of consolidated under-reamed drilled shafts can be smoothly carried out.The integrity of the pile body concrete is classified as Class I,and the self-balancing bearing capacity meets the design requirements.Compared with conventional drilled cast-in-place piles,this technology can reduce the steel reinforcement consumption by 37.4%and concrete consumption by 57.7%,and increase the bearing capacity of a single pile by 33.9%,effectively avoiding the risk of hole collapse of thick sandy soil.The technology of consolidated under-reamed drilled shafts has significant economic,social,and environmental benefits.
作者
丁毅
于坤
石海洋
裴晓峰
祝波
DING Yi;YU Kun;SHI Haiyang;PEI Xiaofeng;ZHU Bo(Shandong Provincial Communications Planning and Design Institute Group Co.,Ltd.,Jinan,Shandong 250031,China;Tianjin Transportation Science Research Institute,Tianjin 300074,China;Guangdong Panshi Foundation Engineering Technology Co.,Ltd.,Shenzhen,Guangdong 518101,China)
出处
《中外公路》
2025年第6期209-217,共9页
Journal of China & Foreign Highway
基金
山东省交通规划设计院集团有限公司项目(编号:BZ202210)。
关键词
固结扩盘桩
自平衡试验
承载特性
塌孔风险
水泥土固结体
盘腔完整性
consolidated under-reamed drilled shaft
self-balancing test
load bearing characteristic
hole collapse risk
consolidation body of cement soil
disc cavity integrity
