利用模型試驗模擬邊坡受震之研究

The Model Simulation for Seismic Slope Behavior

許孝源(Hsiao-Yuan Hsu)

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.2010.00435

摘要

台灣位於環太平洋地震帶，山多平原少又不時發生地震，因此邊坡破壞為常見的災害之一，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，因此王國隆於2004年開發小型振動台。
本研究藉由小型震動台模擬邊坡滑動之行為，以九組試驗分別改變坡高及坡角進行比對，主要比對坡頂退後距離、坡趾影響範圍以及坡面滑動距離。破壞過程中以高速攝影機拍攝下邊坡滑動表面之情形以顆粒影像流速分析(Particle Imaging Velocimetry)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，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，由初步成果來看，在坡面有明顯變化時，利用掃瞄技術確實可以進行定量分析之用。由PIV分析結果與加速度計比對出破壞時間，利用標點位移法推算滑動面所在，由滑動面估算臨界加速度，再經由Newmark位移法計算出滑動距離。
數值軟體FLAC模擬物理模型試驗結果，由數值模擬結果來對照與PIV分析坡面滑動時時間與位移之關係。藉由FLAC數值模擬可推算出滑動位置，可與標點位移法比對，在坡頂位置大致相同，但在坡趾FLAC所得之滑動面較淺。

關鍵字

地震加速度 ； 邊坡破壞

並列摘要

Taiwan is situated on the earthquake-prone Pacific Rim. It is mountainous so slope failure is one of the common natural disasters in Taiwan. To further understand the mechanism of landslides triggered by earthquake and its seismic behavior, Lin and Wang have conducted large scale seismic slope model tests at the NCREE since 2003. To simulate the results to supplement the Full scale test, Wang developed the small-scale shaking table in 2004.
This research used small-scale shaking table to simulate seismic slope behaviors. Nine separate experiments were done to correlate crest development、toe development and run-out distance with changing slope height and angle. During the test a high speed camera was used to record slope sliding, PIV analysis was performed to understand the slope displacement variations. Also laser scanning was used before and after to get the average profile of slope for quantitative analysis of slope elevation change. Preliminary results show that when there is a significant change in the slope, laser scanning helps providing quantitative analysis. From PIV analysis results and accelerometer results, the failure time can be determined. Using punctuation displacement method we figure out where the sliding surface is, from sliding surface the critical acceleration in Newmark’s method was calculated along with the run-out distance.
Numerical software FLAC was used tosimulate results of physical models. From numerical model results were compared to PIV results when analyzing time-displacement relations during slope sliding. Through numerical simulation we can calculate the location of sliding, and compare it with punctuation displacement method. At the top of the slope it is the same, but at the toe of slope FLAC shows a shallower sliding surface.

並列關鍵字

Acceleration ； Slope failure ； FLAC ； PIV

參考文獻

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