桩端岩溶三维超声成像方法及应用研究  

Study on Three-dimensional Ultrasonic Imaging Method and Application of Karst under Pile

作　　者：孙红林[1] 张邦[1] 刘铁华[1] 刘铁[1] 化希瑞[1] 陈健 汪文刚 SUN Honglin;ZHANG Bang;LIU Tiehua;LIU Tie;HUA Xirui;CHEN Jian;WANG Wengang(China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430063,China;Geoco(Chongqing)Instrument Co.Ltd,Chongqing 400713,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]国科(重庆)仪器有限公司,重庆400713

出　　处：《铁道工程学报》2024年第2期26-32,37,共8页Journal of Railway Engineering Society

基　　金：湖北省重点研发项目(2021BAA050);中铁第四勘察设计院集团有限公司重点研发项目(2020K37,2021C15)。

摘　　要：研究目的:岩溶地区大直径桩基础受桩端岩溶的威胁大,探查不清或处理不当时可能会出现桩基承载力不足等严重工程质量问题,现有探测方法难以在桩底复杂泥水环境下实现桩端三维精细化探测。本文基于超声相控阵全聚焦成像原理,提出一种全新的桩端岩溶三维探测方法,以实现对桩端一定范围内地质结构进行三维高精度成像。研究结论:(1)本方法和装备在桩底采集超声数据并成像,可对桩端一定深度和冲切角范围内岩溶三维高精度成像;(2)足尺模型试验表明本装备可探测桩端10 m以内溶洞且探测精度优于0.1 m;(3)工程实践表明本装备可有效查明桩端岩溶、破碎裂隙,探测结果准确可靠;(4)本装备能适应桩底各种恶劣的环境,探测过程简单高效,时效性强,对保障岩溶区桩基施工安全与质量控制具有重要的意义。Research purposes:Large diameter pile foundation in karst area is threatened by the karst underneath the pile,and serious engineering quality problems such as insufficient bearing capacity of pile foundation may occur when the exploration is not clear or improper treatment is done.Existing detection methods are difficult to achieve 3D fine detection below the pile bottom inthe complex muddy water environment.Based onthe principle of ultrasonic phased arrayfull-focusimaging,this paper proposes a new three-dimensional karst detection method to realize three-dimensional high-precision imaging of geological structures below the pile base.Research conclusions:(1)The method and equipment can collect ultrasonic data and image the karst in a certain depth and punching angle below the pile bottom.(2)Full-scale model test shows that the equipment can detect karst caves within 10 m below the pile bottom and the detection accuracy is better than 0.1 m.(3)Engineering practice shows that the equipment can effectively identify karst and fracture fractures below the pile bottom,and the detection results are accurate and reliable.(4)The equipment can adapt to various harsh environment of pile bottom,the detection process is simple and efficient,and the timeliness is strong,which is of great significance for ensuring the construction safety and quality control of pile founda⁃tion in karst area.

关 键 词：大直径桩 岩溶探测 超声相控 三维成像 高精度 

分 类 号：TU473[建筑科学—结构工程]