穿地雷達探測淺水域下構造物之研究

The Detection of Structure under Shallow Water Surface Using Ground-penetrating Radar

黃天福(Tien-Fu Huang) ； 黃中偉(Choung-Wei Huang) ； 陳永祥(Yeong-Shiang Chen)

《中華水土保持學報》 28卷4期 (1997/12) Pp. 333-339

https://doi.org/10.29417/JCSWC.199712_28(4).0007

摘要

穿地雷達探測是偵測地下埋設物的一種技術，由於國內未見以穿地雷達探測水面下構造物位址與水深之文獻，而國外則有運用穿地雷達探測河川斷面變化之文獻，因此，本文旨在進一步探討應用穿地雷達探測淺水域下構造物與水深方法之適用性，並分析輸出訊號之特性。經由本文之研究得知：（1）使用穿地雷達探測水面下構造物與水深時，藉由選擇適宜之頻率與回波時域範圍，即可從輸出之掃瞄圖清楚地顯示鋼筋混凝土構造物之位址。（2）在淺水域應使用較小的回波時域範圍來探測水面下構造物與水深，才可得到較佳的效果。（3）水深測量之方法，首先選定一已知深度水域，推算出電磁波在水中的傳播速度以及相對介電性，並可將回波時域座標轉換爲水深座標，配合欲探測點位之回波時域訊號圖，便可換算出欲探測點位之水深值。（4）有鋼筋混凝土構造物存在時，其回波頻域位於低氟處會產生明顯之峰值。

關鍵字

穿地雷達 ； 淺水 ； 構造物

並列摘要

The technique of Ground-penetrating Radar (GPR) is a powerful tool used for geophysical exploration. In this study, the focus is laid on the method of investigation and evaluation of feasibility when GPR technique is adopted for detectingstructure and water depth under shallow water surface. The result of the study are concluded as follows: (1) If the frequency of incident wave and time domain of reflex wave is properly selected then the site of soil structure under the water surface by the output diagrams of GPR is clearly seen. (2) It is much better to use smaller time domain of reflex wave for detecting structure and water depth under shallow water surface. (3) The method of surveying water depth by GPR is to select a site where water depth is known, then to calculate the velocity of electromagnetic wave in water and transform time domain coordinate into water depth coordinate, finally to judge the site of unknown water depth in the output diagrams of GPR and then calculate the water depth. (4) If a reinforced concrete structure exists under water surface, a peak value in lower frequency for the frequency domain of the reflex wave is clearly produced.

並列關鍵字

GPR ； Shallow Water ； Structure