大直径桩底岩溶三维探测试验研究  

Experimental Study on Three⁃dimensional Detection of Karst at Base of Large Diameter Pile

作　　者：张邦[1] 刘铁华[1] 刘铁[1] 化希瑞[1] ZHANG Bang;LIU Tiehua;LIU Tie;HUA Xirui(China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道建筑》2023年第10期124-130,共7页Railway Engineering

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

摘　　要：岩溶地区桥梁大直径桩基础受桩底岩溶威胁大,桩基施工过程中,在桩底狭小空间、泥浆沉渣富集等环境下,难以实现桩底三维精细探测。基于此,根据桩底探测环境和岩溶发育特点,提出了基于电磁波的桩底瞬变电磁方法和基于弹性波的桩底超声成像方法。通过建立足尺桩基岩溶模型,与现有地质雷达法和桩底声呐法对比,分别试验了所提方法对溶腔模型的探测效果,并总结出不同探测方法适用的桩基类型与异常解释原则。从适应环境、操作难度、探测深度、盲区、分辨率、解译、三维成像等方面比较不同桩底岩溶探测方法,综合来看,桩底超声成像方法有明显的优势,为大直径桩底岩溶探测提供了简单、有效的探测手段。The large diameter pile foundation of bridges in karst areas was greatly threatened by karst at the pile base.During the construction of pile foundations,it was difficult to achieve three-dimensional precise detection of the pile base in environments such as narrow space at the pile base and rich mud and sediment.Based on this,according to the detection environment at the pile base and the characteristics of karst development,the methods of pile base transient electromagnetic based on electromagnetic waves and pile base ultrasonic imaging based on elastic waves were proposed.By establishing a full-scale pile foundation karst model and comparing it with the existing geological radar method and pile base sonar method,the detection effect of the karst cavity model was tested.The applicable pile foundation types and anomaly interpretation principles for different detection methods were summarized.Comparing different pile base karst detection methods in terms of adaptability to the environment,operational difficulty,detection depth,blind spots,resolution,interpretation,3D imaging,etc.Overall,the pile base ultrasonic imaging method has obvious advantages,providing a simple and effective detection means for large diameter pile base detection in karst areas.

关 键 词：桥梁 岩溶探测 试验研究 大直径桩 电磁波 弹性波 三维成像 

分 类 号：TU473[建筑科学—结构工程] U443.15[建筑科学—土工工程]