| 摘要: | 本研究概分「超震法於模型混凝土樁驗證」，以及「樁柱式基礎橋梁之深度探測與驗證」兩階段研究，彙整各類基礎檢測文獻，串接波傳理論、分析，以及實驗，組裝客製化超震檢測儀器，擇定長徑比8至25之譜，直徑為0.1至0.25公尺不等之模型混凝土樁，著重敲擊型式與位置、感測器排列型式、感測器間距，以及長徑比等四個重要參數之超震檢測實驗與分析，是項結果顯示：需於長徑比大於20之分析頻率上設限。另採反算驗證長度估算可行性，驗證互易定理之適用性，以及探討部分埋置狀態下之波傳行為；針對兩類缺陷模型樁，結合導波與HHT分析進行缺陷位置辨識；擇定三處現地樁柱式橋梁基礎(含一處跨水域之雙橋)，依基礎深度檢測策略，進行跨29根墩柱之地電阻影像探測分析，以及7根墩柱之超震檢測實驗，並佐以橋梁設計資料，驗證超震檢測於樁柱式基礎之現地實務性；另於實驗場進行模型混凝土樁之地電阻影像探測技術複核
。綜合模型樁與現地野外實驗之操作實證經驗，發展超震檢測標準作業流程。
關鍵字：超震檢測、波形序列分析、頻譜分析、導波、頻散撓波、共振頻率、基樁深度檢測
;This research consists of two phase investigations, including Ultra-Seismic Inspection Verification on Model Concrete Piles and Depth Inspection and Verification on Pile Bent Foundations. Relevant foundation testing and the relation among theory, analysis method, and experiment for wave propagation are reviewed in detail. Eight model concrete piles with varying diameters from 0.1 to 0.25 m are cast for different slenderness ratios of 8~25. Using a customer-made ultra- seismic apparatus, traction-free and partially-embedded experiments are selected for parametric analysis, including impact pattern/position, sensor array pattern, sensor spacing, and length-to- diameter ratio. Well resonance predictions are found in the different conditions of impact pattern/position, sensor array pattern, and sensor spacing. A frequency limitation is suggested for the piles with length-to-diameter ratios more than 20. The inverse computation for pile length estimate and reciprocal principle are positively confirmed in the ultra-seismic inspection. Defect identification analysis is developed on two kinds of defected piles by using guided wave and HHT analysis. The foundation inspection strategy is applied to evaluate the pile bent lengths on 4 bridges, including two overwater bridges. The electrical resistivity tomography inspection outlines surrounding geological conditions and rough depths over 29 pile bents and the ultra-seismic inspection provides detailed depths on 7 pile bents, which are verified with the bridge design charts. A standard operation process is suggested for the ultra-seismic inspection on pile bent depths.
Keywords: Ultra-seismic inspection, Waveform series analysis, Frequency spectrum analysis, Guided wave, Dispersive flexural wave, Resonance frequency, Pile depth inspection |
