【作者】 朱晓亮； 方升； 魏豪； 戴国亮； 龚维明； 赵文庆； 陈智伟；

【Author】 ZHU Xiao-liang;FANG Sheng;WEI Hao;DAI Guo-liang;GONG Wei-ming;ZHAO Wen-qing;CHEN Zhi-wei;Road & Bridge International Co.,Ltd.;School of Civil Engineering,Southeast University;Advanced Ocean Institute,Southeast University;

【机构】 中交路桥建设有限公司； 东南大学土木工程学院； 东南大学南通海洋高等研究院；

【摘要】 针对悬索桥锚碇在深厚软土层和高承压水复杂地质条件进行超深基坑开挖的地基承载力与坑底抗突涌稳定性问题,以张靖皋长江大桥北航道桥南锚碇工程为背景,创新性地采用D-RJP高压旋喷桩技术实施坑底地基加固,在软土层中创造一个渗透系数、承载力和基底摩擦系数满足要求的复合地基,进而有效改善锚碇地基的工程性质。并通过成桩质量检测、地基承载力和基底摩擦系数试验以及基坑抗突涌分析,系统验证了D-RJP高压旋喷桩复合地基的有效性。试验表明:桩体平均强度为3.01～8.21MPa,平均渗透系数为1.67×10^-7～2.52×10^-7cm/s,复合地基承载力大于1200kPa,基底摩擦系数为0.44～0.52,均达到设计要求。采用有限元分析进一步揭示了D-RJP高压旋喷桩复合地基可有效抑制坑底突涌破坏,证实D-RJP高压旋喷桩地基加固技术对超深基坑抗突涌稳定性的显著提升作用。为以后类似地质条件下的悬索桥锚碇超深基坑地基加固工程提供了重要技术支撑。更多还原

【Abstract】 Addressing the challenges of foundation bearing capacity and excavation bottom anti-heaving stability during ultra-deep excavation of suspension bridge anchorages in complex geological conditions featuring thick soft soil layers and confined water,this study innovatively employs D-RJP high-pressure jet grouting technology for foundation reinforcement at the excavation base.Based on the South Anchorage Project of the North Channel Bridge of Zhangjinggao Yangtze River Bridge,this technique creates an artificial composite foundation within soft soil layers that meets required permeability coefficients,bearing capacity,and base friction coefficients,thereby effectively enhancing the engineering properties of the anchorage foundation.Through pile quality inspection,foundation bearing capacity and base friction coefficient tests,and anti-heaving stability analysis,the effectiveness of the D-RJP composite foundation is systematically validated.Test results indicate:average pile strength of 3.01～8.21 MPa,average permeability coefficient of 1.67 × 10^-7～2.52 × 10^-7 cm/s,characteristic value of composite foundation bearing capacity exceeding1200 kPa,and base friction coefficient of 0.44～0.52,all satisfying design requirements.Finite element analysis further demonstrates that the D-RJP composite foundation effectively suppresses heaving failure at the excavation bottom,confirming the technology’s significant enhancement of anti-heaving stability in ultra-deep excavations.This study provides crucial technical support for future foundation reinforcement projects in ultra-deep excavations of suspension bridge anchorages under similar geological conditions.更多还原