應用透地雷達檢測柔性鋪面下回填路基厚度之研究

Application of GPR on the Investigation of Subgrade Thickness Beneath Flexible Pavement

戴維萱(Wei-Hsuan Tai)

指導教授 ： 林商裕 ； 賴俊仁

朝陽科技大學/理工學院/營建工程系/碩士(2010年)

摘要

許多道路工程相關的問題，如面層厚度不足、級配不良或是路基回填不實等，時常造成道路大範圍的破損。以透地雷達技術檢測柔性鋪面下回填路基之厚度，能快速、經濟的檢測調查品質。
本研究採用250MHz、500MHz與1000MHz三種不同頻率之MaLa透地雷達天線，配合RAMAC Ground Vision解析軟體，在已有明挖試坑資料的路段進行現地試驗、影像收集處理，找出較合適之天線頻率、濾波處理方式，並將試坑資料與影像作一比較分析。
結果如下：(1)影像圖波形受碎石級配影響有繞射現象產生，使影像圖波形呈現不規則，瀝青混凝土路面經過開挖回填後，在影像圖上會產生較平緩之波形。(2)柔性鋪面下之瀝青混凝土面層、級配底層、路基的分界，可以由影像圖上之特徵清楚的辨別出路基的厚度，以及其連續的變化。(3)天線頻率1000MHz用於探測道路瀝青混凝土面層的效果良好；若欲探測級配底層、路基則採用天線頻率500MHz、250MHz。(4) 帶通濾波+Automatic Gain Control處理後，柔性鋪面下瀝青混凝土面層、級配底層、路基的分界較清晰，而使用水平濾波易使各層分界模糊，不利於影像判讀。

關鍵字

柔性鋪面 ； 透地雷達 ； 濾波處理 ； 路基

並列摘要

Many roadwork related issues, such as the thickness of pavement layer, poor grading of backfill material, or poor compaction of backfills may cause extensive road damage. The Ground Penetration Radar can be used to detect the defects mentioned above rapidly.
By using 250 MHz, 500 MHz and 1000 MHz antenna with RAMAC Ground Vision software, the effects of antenna frequency and filtering techniques on the GPR images were studied.
Results of this study show that：(1) The GPR images are affected by the grain size of the subgrade due to the diffraction phenomenon. (2)With suitable frequency of antenna, the boundaries between pavement, subgrade and base material can be identified. (3)A 1000MHz antenna is more suitable to detect the thickness of pavement. The depth of subgrade, or base material can be detected using antenna frequencies of 500MHz and 250MHz. (4)With Band Pass filter and Automatic gain control, the boundaries between pavement, subgrade and base material is more easy to interpret in the GPR images.

並列關鍵字

filter ； Flexible pavement ； Ground Penetrating Radar ； Subgrade

參考文獻

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