現地跨孔波速檢測軟體之開發

Development of a software for body wave velocities using Cross-Hole Tests

曾志瑋(Zhi-Wei Ceng)

指導教授 ： 賴俊仁

朝陽科技大學/理工學院/營建工程系/碩士(2009年)

摘要

現行之跨孔性震測法對於測得土層波速仍然存在許多需要改進之處，且以往國內與跨孔震測法相關的研究以數值模擬為主流，實地進行現地測量的研究並不多，故本研究針對土壤之動態行為，選擇破壞性震測法中應用較為普遍的跨孔式震測法，來進行檢測軟體程式的開發及現地跨孔波速之檢測。
本研究檢測軟體以LabVIEW (Laboratory Virtual Instrument Engineering Workbench)來撰寫程式，現地檢測採用蕭秉彝(2007)碩士論文所使用的氣壓式衝擊錘做為敲擊震源，以現有的速度規為接收器，利用所開發的程式來擷取震波訊號，並進行判讀及分析，測得波速。
由本研究所得到之結果得知：利用Labview所開發的檢測軟體對震波訊號具有擷取、顯示、判讀及計算的功能，並且由正反向接收訊號同時顯示可較準確的判讀出P波、S波到達之時間位置，有效的求取震波波速。由實驗結果顯示，利用一速度規來偵測震源的波形可明確的判讀出震源的激發時間，故此震源的激發時間對P波或S波在測得波速的準確度上並無影響，而在接收器之波形圖上，採用正反向訊號交點來判斷震波到達時間計算波速，可避免因選點方式的差異而影響波速準確度。

關鍵字

跨孔震測法 ； LabVIEW ； 震波波速

並列摘要

In situ cross-hole seismic tests are performed by many organizations on a routinebasis to determine the dynamic properties of soils and rocks for engineering analyses. However, there are still many improvements need for accurate assessment of the body wave velocities, especially in the area of data acquisition and signal analysis. Therefore, the objective of this thesis is to develop a system which can be used for the determination of dynamic soil properties through cross-hole seismic tests.
In this study, a pneumatic hammer developed in the past (Hsiao, 2007) is utilized as the seismic source. Two triaxial geophones are used as the receivers. A software which can acquire and analyze data for cross-hole seismic tests is developed using LabVIEW (Laboratory Virtual Instrument Engineering Workbench).
Based on the experience learned form this thesis, it can be concluded that using the LabVIEW platform can save time and money. The developed software and can acquire, display and analyze data for cross-hole seismic tests at the same time. In conjunction with the pneumatic hammer impact source, the new software can display the waveforms of forward and reverse strike at the same chart, thus making determination of the arrival time for both P-wave and S-wave much easier.

並列關鍵字

body wave velocities. ； LabVIEW ； cross-hole seismic tests

參考文獻

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【2】Richart, F. E. Jr., Wood, R. D. and Hall, J. R. Jr., 〝Vibration of Soils and Foundations〞, Prentice-Hall Publishing Company, New Jersey, 1970.

【3】Hoar, R. J. and Stokoe, K. H., “Field and Laboratory Measurements of Material Damping of Soil in Shear,” Proceeding, 8th World Conference on Earthquake Engineering, San Francisco, Vol.3, pp. 47-54, 1984.