小型振動台模擬邊坡受震行為之研究

Modeling Seismic Slope Behavior Using Small Scale Shaking Table

鄭巽澤(Hsun-Tse Cheng)

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(2006年)

https://doi.org/10.6342/NTU.2006.01884

摘要

摘 要
台灣於1999年遭受規模7.3的921集集大地震憾動全台，不但造成人員傷亡、房屋倒塌，更引發許多邊坡產生滑動破壞。而動態邊坡分析自擬靜態模式開始到滑動塊體的分析方式，皆有簡化假設條件於其中。為了直接了解邊坡受震反應，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，以了解邊坡受震過程中之動態行為反應。更在2004年開發室內小型振動台，期望將邊坡動態模擬試驗常態化，以有利於動態研究分析的發展。

因此本研究期望藉由小型振動台操作上的便利性，能有效的模擬出邊坡滑動行為。在試驗過程中改變邊坡特定因子坡角與坡高進行試驗，發現在以坡角改變時，所觀察出的邊坡滑動發展主要由坡頂開始向下滑移推擠下方的坡面造成整體性的坡面滑動。而在不同坡高為變數方面，因在振動時由於坡面較不穩定因此破壞型式以坡面快速滑落現象為主。

另外以試驗中以影像觀測記錄邊坡行為，並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。利用紅外線掃瞄方式，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之依據，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。最後以數值軟體FLAC模擬物理模型試驗結果，由數值模擬結果來看在定性方面如坡面位移場及剪應變增量之分佈有相當好的吻合度。

關鍵字

振動台 ； 動態行為 ； 數值分析

並列摘要

Abstract

The Chi-Chi earthquake struck Taiwan in 1999. Causing many people dead and injured, buildings destroyed and also inducing numerous landslides . The pseudo static and sliding block analysis for seismic analysis slope usually involve many assumptions. In order to understand the behavior of slope subjected to earthquake, Wang (2003) used large shaking table to perform large scale model slope test in NCREE to observe the dynamic behavior of slope. The small shaking table was developed in laboratory in 2004 to facilitate the laboratory slope model test and which has advantage of easy operation and specimen preparation.
The aim of this study is to take advantage of the convenience of the small shaking table to simulate and study the seismic slope behavior. The control factors such as slope angle and slope height have been changed during tests. The development of sliding initiated from the slope crest and moving toward the slope toe causing heave when the control factor is slope angle. As the control slope height increases , the slope became more unstable with ,and development of the failure obvious when the dynamic force is applied the specimen.
The images of model slope behavior were recorded during tests and image analysis using PIV is performed to tract the displacement vectors when landslide initiates. 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 according to the average height to two curves. The FLAC program was used to simulate the displacement vector and shear strain increment and the results good consistence with test results.

並列關鍵字

shaking table ； dynamic behavior ； numerical analysis

參考文獻

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