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碩士論文公告區 |
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| 年度： | 95 | |
| 姓名： | 蕭秉彝(Ping-Yi Hsiao) | |
| 論文題目(中)： | 跨孔式震波檢測敲擊源之研發 | |
| 論文題目(英)： | Development of An Impact Source for Cross-Hole Seismic Test | |
| 摘要(中)： | ||
| 跨孔式震測法是一種在現地量測土壤動態性質的方法，在工程界運用廣泛。但國內在此方面的研究多以數值模擬為主，實際進行敲擊數據研究並不多，且多是運用傳統方法，在進行SPT試驗後進行，錘擊能量損失大且須修正以求精確的波傳時間。 本論文利用自行開發之衝擊錘，敲擊混凝土取得波形數據進行研究分析，除了求取震波波速，計算相關參數外，也針對實驗的過程和衝擊錘的運作方式進行討論，找出適合跨孔式震測法的實驗配置，討論衝擊錘作為新型跨孔震源的可行性和限制。 整理研究結果得到以下結論：本論文使用之氣壓式衝擊錘在現地確實能產生有效的震波，而產生的震波經由接收器進行擷取分析後，產生的波形和波傳理論相符，判讀波形後計算所得的混凝土波速也和其他儀器測量所得相當接近，實驗的配置則以接收器直接面對衝擊源，從面對方向(X向)的接收器可找到最明顯的P波抵達時間，S波則建議以與垂直鑽孔軸線方向進行敲擊，及與軸線垂直方向的接收器可找到最清楚的S波抵達時間。 |
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| 摘要(英)： | ||
| In situ measurements of seismic wave velocities are performed by many organizations on a routine basis to determine the dynamic properties of soils and rocks for engineering analyses. One of the most widely used geophysical approaches to obtain the compression and shear wave velocity profiles of a site is the cross-hole method. The basic concept of the cross-hole method is very simple. That is, just pass the desired seismic waves over a given travel path and measure the travel time. The wave propagation velocities of each type can be calculated by dividing the travel distance by travel time. However, for very accurate assessment of the wave velocities, a proper source to generate the seismic wave is crucial. The objective of this study is to develop a pneumatic hammer which can be used as a seismic source for cross-hole tests. The hammer utilizes compressed air to compress a spring through a piston. When the piston is released, elastic energy stored in the spring drives the piston back and expands the tip a wedge device to impact the wall of borehole casing. The main advantage of the new device lies in that the impact force produced by this hammer is directional. Therefore, it can generate primary P-wave when the tip is oriented toward the receiver and primary S-wave while the tip is oriented perpendicular to the receiver. Preliminary test results of this study indicate that, with the pneumatic mechanical hammer, identification of the first arrival of P-wave and S-wave is a lot easier than using the traditional seismic sources. |
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| 檔案： | 沒有相關檔案 | |
| 相關連結： | http://ethesys.lib.cyut.edu.tw/ETD-db/ETD-search-c/view_etd?URN=etd-0824107-013711 | |