TDR錯動變形量測之研究

Abstract

錯動變形之監測在工程監測中一直都扮演著重要的地位，錯動變形量測感測器的發展也隨著科技的日新月異而逐漸有所創新，將時域反射法(TDR ,Time Domain Reflectometry)此一先進的被動監測技術應用在錯動變形監測上，更是近年來大地工程變形監測的一項創新。 而現有將TDR應用至變位量測上能然存在許多尚待解決的問題，其中主要的問題是無法準確的量化變形量，且對於變形的模式亦無量化的解析方法。TDR監測之反射訊號受到需多因素的影響，包括變形模式、變形量、纜線長度等。本研究嘗試在理論分析與標定試驗兩方面考慮上述因子，以期能解決TDR變形量化之問題。 在理論分析上，TDR反射訊號完全取決於纜線斷面隨著其軸向之變化，因此本研究包含一可控制壓痕寬度之試驗進行波形的模擬與分析（此一模式亦可加入纜線長度之影響），結果顯示纜線阻抗與壓痕變形量有唯一性。 而室內標定試驗方面，為簡化所欲探討之問題，本研究係考慮剪力破壞所產生之錯動變形模式，並將此模式參數化為剪力帶寬度（W）及錯動變形量（δ），進而製作錯動變形之室內標定盒並且進行相關之影響因素探討試驗，如剪力帶寬度、材料性質、多重反射以及灌漿強度等試驗。

Monitoring slip displacement measurement plays the important role on engineering monitoring. Development of slip displacement measurement sensors is innovate with technology progressing. Advanced passive monitor technology of Time Domain Reflectometry (TDR) applied on slip displacement measurement is an originality recently。 There are unsolved problems on TDR application on slip displacement measurement the major are inaccurate quantification for deformation and the lack of analytical methods for displacement mode. There are many factors affecting reflection of TDR monitor, including displacement mode, deformation, cable length etc. The study attempts to consider the influence of these factors with theoretical analysis and calibration test and expect to solve the problem of TDR deformation quantification。 Theoretically TDR reflection depends on the cable section changed along with the axial direction. This study includes a waveform simulation and analysis tests by controlling the width of crimp （the model is also capable to combine the affection of cable length）. Results show that there is a unique relation between cable impedance and cable deformation. On the aspect of indoor calibration tests, in order to simplify problems, the slip displacement model by shear failure is parameterized by the shear bandwidth (W) and slip displacement (δ). By using a calibration box which is able to simulate the different slip models in soil, tests were proceeded for discovering influences of factors like shear bandwidth of displacement, material property, multiple reflection and grouting strength.