珊瑚礁灰岩层基本性质及后压浆嵌岩桩竖向承载特性试验研究  

Experimental study on the fundamental properties of coral-reef limestone and the vertical bearing behavior of post-grouted rock-socketed shafts

作　　者：段畅 万志辉 戴国亮[2] 郭子龙 胡涛[2] 龚维明[2] 张润泽 DUAN Chang;WAN Zhihui;DAI Guoliang;GUO Zilong;HU Tao;GONG Weiming;ZHANG Runze(College of Transportation Engineering,Nanjing Tech University,Nanjing,Jiangsu 211816,China;School of Civil Engineering,Southeast University,Nanjing,Jiangsu 211189,China)

机构地区：[1]南京工业大学交通运输工程学院,江苏南京211816 [2]东南大学土木工程学院,江苏南京211189

出　　处：《岩石力学与工程学报》2025年第3期721-736,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52008100);中国博士后科学基金面上项目(2022M723534);江苏省高等学校基础科学(自然科学)研究重大项目(23KJA560005)。

摘　　要：海洋中吹填岛礁的开发已成为沿海国家的重要战略举措。以马累-机场岛跨海大桥工程拟建区的珊瑚礁灰岩为研究对象,系统地研究其力学性质和工程特性。基于后压浆嵌岩灌注桩的现场静载试验和钻孔取芯试验,深入探讨珊瑚礁灰岩层中大直径后压浆嵌岩灌注桩的承载与变形特性,并对桩身完整性及后压浆浆液的渗扩范围进行全面评价。试验结果表明,该地区的珊瑚礁灰岩具有密度低、孔隙大、结构独特性、强度各向异性以及胶结程度不均匀等显著特征。大直径后压浆嵌岩灌注桩在该地层中展现出良好的应用前景,压浆后试桩极限承载力提升了3.6%,桩顶位移相比压浆前减小了33.53%。钻孔取芯试验显示,桩端压入的浆液向下渗扩范围约3 m(约2D),显著改善了珊瑚礁灰岩的孔隙结构。最后,通过建立珊瑚礁灰岩完整岩石单轴抗压强度与极限桩侧摩阻力和桩端阻力之间的关系,提出珊瑚礁灰岩层后压浆嵌岩灌注桩承载力设计的计算方法,为后续的工程设计提供了科学依据和理论支持。The development of reclaimed islands and reefs has emerged as an important strategic measure for coastal nations.This paper systematically investigates the mechanical properties and engineering characteristics of coralreef limestone in the proposed area for Male-Airport Island cross-sea bridge project.Based on the results of static load tests and core drilling conducted on post-grouted rock-socketed drilled shafts,this study provides a comprehensive analysis of the bearing deformation characteristics of the shaft embedded in coral-reef limestone before and after grouting.Additionally,the integrity of the shaft and the permeation diffusion range of the grouting are thoroughly evaluated.The test results reveal that the coral-reef limestone exhibits notable characteristics,including low density,large pore sizes,unique structure,strength anisotropy,and uneven cementation.Furthermore,large-diameter postgrouted rock-socketed drilled shafts demonstrate promising application potential in the coral-reef limestone strata.The post-grouting technique enhances the bearing deformation capacity of shaft foundations in coral-reef limestone,with the ultimate bearing capacity of the test shaft increasing by 3.6% after grouting,and the displacement of the shaft head decreasing by 33.53% compared to before grouting.Core drilling tests indicate that the grouting at the shaft tip penetrates approximately 3 m(around 2D)downward,which significantly improves the pore structure of the coral-reef limestone.Finally,by correlating the unconfined compressive strength of intact coral-reef limestone with the ultimate side resistance and tip resistance,this paper develops a computational method for calculating the load capacity of grouted rock-socketed drilled shafts in coral-reef limestone formations.This methodology offers a robust scientific foundation and theoretical basis to guide subsequent engineering applications.

关 键 词：桩基础 珊瑚礁灰岩 后压浆嵌岩桩 工程特性 力学性质 钻孔取芯 单轴抗压强度 

分 类 号：TU473[建筑科学—结构工程]