高密度H/V谱比法在废弃桩基础探测中的应用  

Application of High Density H/V Spectral Ratio Method in the Detection of Abandoned Pile Foundations

作　　者：黄佳坤 Huang Jiakun(Fujian Provincial Institute of Architectural Design and Research Co.,Ltd.,Fuzhou Fujian 350001,China)

机构地区：[1]福建省建筑设计研究院有限公司,福建福州350001

出　　处：《工程地球物理学报》2025年第2期207-215,共9页Chinese Journal of Engineering Geophysics

基　　金：自然资源部丘陵山地地质灾害防治重点实验室(福建省地质灾害重点实验室)开放基金(编号:201WT001)。

摘　　要：地铁盾构施工前需排查各种地下风险源,其中废弃桩基础的探测难度较大。工程实践发现,当地下存在较硬介质时,在其上方地表观测到的微动信号H/V(Horizontal to Vertical)谱比的量值比在其周边背景土层地表观测到的大。利用H/V谱比的这一特征,提出采用高密度H/V谱比法在福州地铁某线盾构区间对废弃的桩基础展开探测,以1 m×1 m的网格在地表上共布置380个检波点,采用三分量的检波器进行数据接收,在每个检波点上采集10~15 min的微动信号,使用Matlab(Matrix Laboratory)编写的程序计算出每个检波点的H/V谱比曲线,并绘制10个H/V剖面图和若干等频率切片图,综合分析各成果剖面划分出多处疑似桩基础异常,指导开挖拔桩施工,最终共拔出15根管桩,桩长约22~24 m,桩径约0.6 m,以盲探的形式实现了废弃桩基础的探测,为后期的盾构施工排除了风险源,方法可供类似工程借鉴。Before subway shield construction,it is necessary to investigate various underground risk sources.Among them,abandoned pile foundations are more difficult to detect.Engineering practice has found that when there is a harder medium underground,the value of the H/V(horizontal to vertical)spectral ratio of the microtremor signals observed on the ground surface above it is larger than that of the characteristic of H/V spectral ratio observed on the ground surface of the surrounding background soil layers.Based on H/V spectral ratio,a high-density H/V spectral ratio method has been proposed to detect some abandoned pile foundations in a shield tunnel section of a certain line of Fuzhou Metro.A total of 380 detection points were arranged on the ground surface with a grid of 1 m×1 m,and the three component detectors were used for data reception.Microtremor signals were collected for 10~15 minutes at each detection point.The H/V spectral ratio curve of each detection point was calculatedand 10 H/V profile diagrams and several equal frequency slice diagrams were drawn using a program written in MATLAB(Matrix Laboratory).Multiple suspected pile foundation anomalies were identified through comprehensive analysis of the profile results,which guided the excavation and pile pulling construction.A total of 15 pipe piles were pulled out,with a length of about 22~24 m and a diameter of about 0.6 m.The blind detection of abandoned pile foundations was achieved,removing the risk source for subsequent shield construction.This method can serve as a reference for similar projects.

关 键 词：高密度H/V谱比法 三分量检波器 微动 桩基础 

分 类 号：P631.4[天文地球—地质矿产勘探]