用于青岛地铁超前地质预报的探地雷达信号分析与去噪技术研究

发布时间：2018-06-30 18:40

本文选题：探地雷达 + 超前地质预报　；参考：《中国海洋大学》2014年硕士论文

【摘要】：青岛市轨道交通一期工程地铁3号线全程为地下线路，长约24.9km，设22座车站，总体呈“西-东-北-西”走向横穿青岛市区。地铁隧道于2011年初开工建设，基于探地雷达技术的超前地质预报工作也随之展开。由于地铁隧洞洞顶埋深小于30m，沿线地层变化较大，，地质灾害体发育，建立不同地质灾害体的GPR异常特征是保证探测效果的关键。此外，隧道封闭的空间结构以及探测现场周围存在的钢拱、施工机械、用电设备等对GPR探测信号产生了严重干扰，甚至完全覆盖了有效信号，易造成解译误判。为解决上述GPR超前预报关键技术，本文分析了青岛地铁3号线236组掌子面实测GPR剖面，总结了典型地质体反射信号和干扰信号的异常特征；并对比理论计算剖面确定了信号识别特征。此外还对GPR噪声信号和去噪方法进行了分析研究，初步确定了噪声的干扰形态和规避方式。研究取得的主要成果如下：（1）确定了不同风化及富水程度岩体的GPR信号特征，分析了施工环境对探测的干扰影响；（2）建立了典型地质体的GPR标准正演剖面，分析了各个地质体引起的反射信号特征；（3）确定了探测过程中钢拱、施工机械噪声的干扰形态及影响范围；（4）常规的高通、低通、带通滤波处理对噪声信号的压制效果不明显，通过在掌子面铅直布线采集的方式，改变了天线响应方向，较大程度地规避了干扰源的影响范围。
[Abstract]:The subway line 3 of the first phase of Qingdao rail transit project is an underground line with a length of about 24.9km, and 22 stations are set up, which are "west, east, north and west" and cross the urban area of Qingdao. The construction of subway tunnel started in early 2011, and the advance geological forecast based on ground penetrating radar (GPR) technology was also carried out. Because the buried depth of the top of subway tunnel is less than 30 m, the strata along the tunnel are changed greatly and the geological hazard body is developed, the key to ensure the detection effect is to establish the abnormal characteristics of GPR of different geological hazard bodies. In addition, the closed space structure of the tunnel and the steel arch, construction machinery and electrical equipment around the detection site have caused serious interference to the GPR detection signal, and even completely covered the effective signal, which is liable to cause interpretation and misjudgment. In order to solve the above key technologies of GPR advanced prediction, this paper analyzes 236 groups of measured GPR profiles on the palm of Qingdao Metro Line 3, and summarizes the abnormal characteristics of the reflected signals and interference signals of typical geological bodies. The characteristics of signal recognition are determined by comparison of theoretical calculation profiles. In addition, the noise signals and denoising methods of GPR are analyzed and studied, and the interference patterns and evading methods of noise are preliminarily determined. The main results are as follows: (1) the characteristics of GPR signal of different weathering and water-rich rock mass are determined, and the influence of construction environment on the detection is analyzed. (2) the GPR standard forward section of typical geological bodies is established, and the characteristics of reflected signals caused by each geological body are analyzed. (3) the interference form and influence range of steel arch and construction machinery noise in the detection process are determined. (4) the conventional high-pass, low-pass and band-pass filter have no obvious effect on the suppression of noise signal. The influence range of interference source is avoided to a large extent.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U456.3;U231;P631.3

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