工程科学学报
工程科學學報
공정과학학보
Journal of University of Science and Technology Beijing
2015年
11期
1397-1402
,共6页
石英砂岩%地质探测%地质雷达%频谱分析
石英砂巖%地質探測%地質雷達%頻譜分析
석영사암%지질탐측%지질뢰체%빈보분석
quartz sandstone%geological exploration%ground penetrating radar%frequency spectrum analysis
经过岩土体介质反射回的地质雷达波特征携带了所穿透的岩土体内部的相关信息,其中地质雷达波频谱主频值可以作为判断岩土体结构特征的一个定量指标. 以围岩为石英砂岩的公路隧道工程为依托,采用MALA地质雷达配100 MHz屏蔽天线,对隧道掌子面前方的石英砂岩体进行超前地质探测试验,分析典型的Ⅴ级、Ⅳ级和Ⅲ级石英砂岩围岩的雷达波形图图像特征和雷达波在岩体介质中传播的傅里叶频谱特征. 通过分析现场试验数据,得出岩体介质的雷达波主频值因自身结构特征和周边环境变化而在一定的敏感频率区间内的规律. 对比分析研究结果与工程开挖实际,表明通过分析超前地质探测获得的雷达波傅里叶频谱主频值特征来反演识别围岩结构特征是切实可行的.
經過巖土體介質反射迴的地質雷達波特徵攜帶瞭所穿透的巖土體內部的相關信息,其中地質雷達波頻譜主頻值可以作為判斷巖土體結構特徵的一箇定量指標. 以圍巖為石英砂巖的公路隧道工程為依託,採用MALA地質雷達配100 MHz屏蔽天線,對隧道掌子麵前方的石英砂巖體進行超前地質探測試驗,分析典型的Ⅴ級、Ⅳ級和Ⅲ級石英砂巖圍巖的雷達波形圖圖像特徵和雷達波在巖體介質中傳播的傅裏葉頻譜特徵. 通過分析現場試驗數據,得齣巖體介質的雷達波主頻值因自身結構特徵和週邊環境變化而在一定的敏感頻率區間內的規律. 對比分析研究結果與工程開挖實際,錶明通過分析超前地質探測穫得的雷達波傅裏葉頻譜主頻值特徵來反縯識彆圍巖結構特徵是切實可行的.
경과암토체개질반사회적지질뢰체파특정휴대료소천투적암토체내부적상관신식,기중지질뢰체파빈보주빈치가이작위판단암토체결구특정적일개정량지표. 이위암위석영사암적공로수도공정위의탁,채용MALA지질뢰체배100 MHz병폐천선,대수도장자면전방적석영사암체진행초전지질탐측시험,분석전형적Ⅴ급、Ⅳ급화Ⅲ급석영사암위암적뢰체파형도도상특정화뢰체파재암체개질중전파적부리협빈보특정. 통과분석현장시험수거,득출암체개질적뢰체파주빈치인자신결구특정화주변배경변화이재일정적민감빈솔구간내적규률. 대비분석연구결과여공정개알실제,표명통과분석초전지질탐측획득적뢰체파부리협빈보주빈치특정래반연식별위암결구특정시절실가행적.
Ground penetrating radar ( GPR) electromagnetic waves which penetrate through rock and soil mediums and are reflec-ted back carry internal information about the target objects. The GPR basic frequency values of Fourier spectra can be used as a quan-titative index of judgment for the structure characteristic of rock and soil mediums. Based on a highway tunnel project with the surrounding rock of quartz sandstone, advanced geological exploration test was carried out in front of the tunnel face with MALA GPR and a 100 MHz shielded antenna. Typical Class Ⅴ, Class Ⅳ and Class Ⅲ quartz sandstone surrounding rock mass were chosen to analyze their waveform graph information characteristic and the Fourier spectrum frequency characteristic during electromagnetic wave propagation in rock mass mediums. The regularity of GPR wave basic frequency values corresponding to the quartz sandstone rock mass medium in a certain sensitive frequency range due to its structure and surrounding environment changes was obtained through field test data analysis. A comparison between the research results and engineering excavation practices shows that it is feasible to invert the basic frequency value characteristic of GPR waves derived from advanced geological exploration for determining the structure character-istics of surrounding rock.