斷層掃瞄是一種藉由量測物體外部資料來反求內部組成的檢測技術。時自今日斷層掃瞄已經發展出許多成熟的理論方法，且被廣泛地應用在地質學與醫學的領域上，然而在透地雷達檢測技術的應用上仍不成熟。因此本研究的目的在探討透地雷達透照結合斷層掃瞄技術於土木構件檢測之實用性與可行性。 試驗方面，對於具有不同裂隙寬之水泥混凝土試體以三個步驟進行試驗：首先進行GPR斷層掃瞄檢測，以不同的天線排列及測點數來分別探討與相互進行比對；第二個步驟，將裂隙試體以GPR反射法施測進行試體檢測，並將其成果剖面與斷層掃瞄顯像進行比對探討；最後實際選擇一建物之鋼筋混凝土柱進行現場實驗，以透地雷達反射法及斷層掃瞄兩種方法施測，檢測柱內可能之鋼筋排列。藉此指出GPR斷層掃瞄在公共建設之非破壞檢測上的可行性。 Tomography is an image technique which generates a cross sectional picture of an object by utilizing the object’s response to the nondestructive, probing energy of an external source. Nowadays the theories and techniques of tomography have been well developed and applied to a number of fields such as Geophysics and Medicine. However, this technique is not well applied in Ground Penetrating Radar method (GPR). Therefore, the feasibility of detecting civil infrastructures by combined the GPR and tomography methods are being evaluated. Three steps involved in the testing of the cement concrete samples with different width of the crack; first, GPR tomographic sounding with different deploying of antenna or different sampling points is being studied. Second, the fractures of the sample are also inspected by reflection GPR survey. The difference between the tomography and reflection results can be recognized. Final, a field test is carried on a R.C. pillar by using both tomography and reflection GPR surveys. The distribution of the steel rabars is recognized. It indicates that the tomographic GPR has great potential for non-destructive inspection of infrastructure.
