小型振動台模擬邊坡滑動情形之研究

Study on sliding behavior of slope using small scale shaking table

陳永昇(Yung-Sheng Chen)

指導教授 ： 林美聆

國立臺灣大學/工學院/土木工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.00974

摘要

921集集大地震，不但造成台灣人民傷亡、房屋倒塌、更引發許多邊坡產生滑動破壞，為更深入了解邊坡受震時破壞發生機制，林美聆與王國隆自2003年起於國家地震中心進行了多組大型邊坡受震模擬試驗，以了解邊坡受震中之動態行為模式。為能於大型試驗進行前預先模擬，因此王國隆學長於2004年開發小型振動台。在本研究中針對其步進馬達輸出功率加以提昇，以使更適用於探討邊坡滑移機制。
本研究期望藉由小型振動台，有效地模擬出邊坡滑動之行為。在試驗過程中以改變邊坡特定因子坡高與坡角準備試體進行試驗。另外，本研究以影像分析方法運用PIV分析坡面位移場關係，了解整體坡面在產生滑動破壞時，坡面位移場分佈變化情況。並且利用雷射掃瞄方式，對於坡面在試驗前後進行掃瞄動作，根據掃瞄所得試驗前後之坡面平均高程曲線來進行坡面變化定量分析。並且量測在坡面上的標點位移向量，利用圖解的方式推測邊坡滑動面的位置。
試驗發現邊坡破壞會從坡頂開始破壞，破壞模式是以塊體滑動的方式進行破壞，從影像分析可以支持塊體滑動破壞的論點。從圖解法可繪出滑動面的位置，發現邊坡破壞試以淺層滑動為主，最後利用數值軟體FLAC，輸入試驗時之加速度資料比對上述滑動面位置，結果相當接近。

關鍵字

振動台

並列摘要

The Chi-Chi earthquake struck Taiwan in 1999 which induced numerous landslides. Using pseudo static and sliding block analysis for seismic slope analysis usually involve simplified assumptions. In order to understand the behavior of slope subjected to earthquake, Wang (2003) used large-scale shaking table model test in NCREE to observe the dynamic behavior of slope. A small-scale shaking table was developed in laboratory in 2004 to facilitate the laboratory slope model test with the advantage of easy operation and specimen preparation.
The objective of this research is to simulate landslide behavior using small-scale shaking table. The control factors including slope height and slope angle have been changed during tests. The images of model slope behavior were recorded during tests and image analysis where performed using PIV to tract the displacement vectors when landslide initiated. The infrared rays were used to scan the surface of specimen, which measured the differences in geometry of specimen before and after test. The deformation of slope was measured based on the average of three profiles, and with motion vectors along the slope. The slip surfaces can be constructed base on geometry method.
It is found that displacement will concentrate at the top of slop when failure occurs, and the sliding behavior is similar to block sliding. Result of PIV analyze also support the sliding-block behavior of the model slope. The slip surfaces constructed using geometry method is shallow, and appears to be consistent with FLAC, The slip surfaces of model test and numerical analysis.

並列關鍵字

shaking table

參考文獻

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