基于MATLAB小波分析的软地基加固探地雷达检测处理方法

从小波分解出发，利用多尺度分解对探地雷达波进行分析，并基于MATLAB的小波分析对深圳市公安局某工地强夯土石墩地基的检测结果进行处理，提出了具体的处理方法。     

云台山隧道与两端线路路基病害的探地雷达检测

采用探地雷达对陇海铁路线云台山隧道及两端线路的路基状况和严重翻浆冒泥病害进行了探测，现场提取了翻浆冒泥土样和基床土样并进行了土工试验，根据探测、试验和现场挖探结果，给出了云台山隧道及两端线路的路基表面以下道碴、基床土和基岩之间界面及其与排水沟的深度关系，阐明了翻浆冒泥病害的成因，据此提出了“水泥土挤密桩加固基床土与土工膜封闭层”病害整治方案，为该段铁路线路病害的整治提供了科学依据和合理方法。     

Analysis of the karst aquifer structure of the Lamalou area (Hérault, France) with ground penetrating radar

The study site at Lamalou karst spring (Hortus karst plateau) is situated 40 km north of Montpellier in France. It consists of a limestone plateau, drained by a karst conduit discharging as a spring. This conduit extends for a few dozen meters in fractured and karstified limestone rocks, 15 to 70 m below the surface. The conduit is accessible from the surface. The main goal of this study is to analyze the surface part of the karst and to highlight the karstic features and among them the conduit, and to test the performances of ground penetrating radar (GPR) in a karstic environment. This method thus appears particularly well adapted to the analysis of the near-surface (<30 m in depth) structure of a karst, especially when clayey coating or soil that absorbs and attenuates the radar is rare and discontinuous. A GPR pulseEKKO 100 (Sensors and Software) was used on the site with a 50-MHz antenna frequency. The results highlight structures characterizing the karstic environment: the epikarst, bedding planes, fractured and karstified zones, compact and massive rock and karrens, a typical karst landform. One of the sections revealed in detail the main conduit located at a depth of 20 m, and made it possible to determine its geometry. This site offers possibilities of validation of the GPR data by giving direct access to the karstic conduits and through two cored boreholes. These direct observations confirm the interpretation of all the GPR sections.     

Reweighting strategies in seismic deconvolution

Reweighting strategies have been widely used to diminish the influence of outliers in inverse problems. In a similar fashion, they can be used to design the regularization term that must be incorporated to solve an inverse problem successfully. Zero-order quadratic regularization, or damped least squares (pre-whitening) is a common procedure used to regularize the deconvolution problem. This procedure entails the definition of a constant damping term which is used to control the roughness of the deconvolved trace. In this paper I examine two different regularization criteria that lead to an algorithm where the damping term is adapted to successfully retrieve a broad-band reflectivity.
Synthetic and field data examples are used to illustrate the ability of the algorithm to deconvolve seismic traces.     

Detection of underground cavities by combining gravity,magnetic and ground penetrating radar surveys: a case study from the Zaragoza area,NE Spain

A geophysical survey routine is proposed to detect underground cavities and dolines; it is based on the sequential application of magnetic, low-frequency ground penetrating radar (GPR) and microgravity techniques. A case study near Zaragoza (Ebro valley, Spain) demonstrates the applicability of these methods. The strong contrast of magnetic and electromagnetic properties (and to a lesser scale, of density) between the doline filling and the surrounding stratified Tertiary and Quaternary rocks allows the shape of filled cavities to be clearly outlined by these methods.     

探地雷达技术在公路病害探测中的应用

探地雷达是一种基于介质电磁性质差异的非破坏性测试技术,具有快速、简捷、抗干扰能力强、分辨率高等优点。公路路面、基层、路基和地基等结构层之间存在电磁性质差异,且路基病害造成的结构破坏导致各种介质相互混合,也使得病害区段介质电磁性质与周围明显不同。因此,公路病害的雷达探测具备基本物理前提。以某高速公路裂缝等病害探测为实例,阐述了探地雷达原理和工作方法技术及其在裂缝发展程度、路基不密实区、是否存在空洞等病害特征及其成因探测中的有效性。     

地震计阶跃标定信号去除方法研究

为去除地震计记录信号中的阶跃标定信号,将理论阶跃信号与多项式拟合方法相结合,提出一种去除阶跃标定信号的方法。通过对比不同时段地脉动信号的功率谱密度(PSD)发现,应用本文方法去除阶跃标定信号后的地震信号的PSD与真实信号的PSD较为接近,同时地震信号的各种震相可被清晰还原。     

地球物理方法在地质灾害勘查中的应用

结合实例介绍了探地雷达、电法及地震勘探等方法在地质灾害中的应用效果,对其它方法如声波检测技术、重力测量及氡气测量等方法在地质灾害勘查中的应用进行了简要总结,并提出了目前地质灾害勘查中存在的一些问题.     

水闸闸基隐患探测雷达图像特征分析

水闸闸基隐患严重威胁水闸安全，闸基淘空是水闸较常见的隐患之一。闸底地基垫层在水闸上下游水位差的作用下，经一段时间的运行后，往往会形成强渗流层和淘空区，洪水到来时便产生管涌，危及水闸的安全运行和人民的生命财产安全。利用探地雷达技术可探测出闸基冲刷剥蚀程度、淘空区的位置、范围、发育程度及规模，便于及早采取防范措施，进行加固处理。探地雷达技术是水闸闸基隐患探测的有效手段，雷达图像的特征分析是雷达资料解释的关键，通过雷达图像的特征分析，可判译出闸基隐患的具体部位和类型。     

宽带探地雷达系统研究及在工程检测的应用

宽带探地雷达系统以其高分辨率而受到重视。我们系统地分析、模拟和实验测试了宽带天线，在同络分析仪的基础上研究和开发了宽带的探地雷达系统。对不同模型进行探测，结果表明系统具有很高的分辨率。更重要的是该系统可以在与被探测介质不接触的情况下对介质内部进行探测，具有很高的工作效率。在工程质量检测中将具有巨大应用前景。