| 研究生: |
黃忠皓 Chung-Hao Huang |
|---|---|
| 論文名稱: |
以離散元素法探討加勁砂土層在淺基礎受載重下之力學 The Mechanical Behavior Of Reinforced Sand Layer Under Shallow Foundation Loading Using Discrete Element Method |
| 指導教授: |
黃文昭
Wen-Chao Huang |
| 口試委員: | |
| 學位類別: |
碩士 Master |
| 系所名稱: |
工學院 - 土木工程學系 Department of Civil Engineering |
| 論文出版年: | 2015 |
| 畢業學年度: | 103 |
| 語文別: | 中文 |
| 論文頁數: | 139 |
| 中文關鍵詞: | 離散元素法 、平板載重試驗 、地工格網 、微觀 |
| 外文關鍵詞: | discrete element method, plate load test, microscopic, geo-grid |
| 相關次數: | 點閱:9 下載:0 |
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台灣地狹人稠,都市土地之有效利用為工程師們的一大挑戰,因為台灣
位於歐亞板塊與菲律賓板塊交界,活動斷層附近之土地利用更需了解斷層
錯動對附近工程設施之影響。斷層錯動造成地表變形可能會引起過大角變
量,導致斷層上方或是斷層附近的建築物損壞並導致結構物坍塌,由於此類
災害不可避免,如何利用大地工程之減災措施來降低人財損失為近年來重
要的研究課題。
前人研究中大部分以有限元素法模擬斷層錯動之力學行為,然而利用
有限元素法可能無法處理或模擬斷層錯動時造成之大變形以及裂縫產生與
延伸無法有效於模型中觀察,所以本研究利用離散元素法,使用 PFC2D 軟
體,模擬基礎載重下土壤承載力微觀變化與斷層錯動後斷層上部覆土之位
移情形。廖泓韻(2013)研究中提到顆粒接觸勁度、剪切勁度以及顆粒基本摩
擦角對整體之宏觀摩擦角有關;Sawwaf(2010)以有限元素模擬地工格網在砂
土層平板加載的加勁效果,並以物理實驗比較,本研究利用廖泓韻之參數做
原始建模,並於模型中鋪設地工格網進行平板加壓,再以 Sawwaf 物理試驗
之結果做參數驗證,最後利用已驗證之參數進行不同摩擦角土壤承載力模
擬,再以改良的模型模擬不同的層數、格網寬度及格網位置做承載力比較。
Taiwan is located in between the boundaries of the Eurasian and Philippine
plate, so the use of the land over the fault is a major issue. The dislocation
provokes a deformation in the surface causing an angular distortion; it could make
the upper side of the fault or the architectures surrounding it to get damaged,
causing structures to collapse. We can decide to use bigger projects, preventing
methods to reduce human and financial losses.
The majority of previous studies take finite element methods to simulate the
behavior of faults, and use the disadvantages of grid simulations like: particle-
degree rotation and limited displacement, the inseparability of particles, the
inability to detect particle contact situation, large changes can’t be simulated and
the show up and extension of cracks can’t be observed. Therefore, this research
uses discrete element method-PFC, simulating the dislocation of the fault after the
overburden of the top of the fault is affected by the displacement situation of the
bottom part’s dislocation. In the research of Liao(2013) ,the stiffness of the
particle’s contact, shear stiffness and particle basic friction are related to the
integral friction; the research of Sawwaf (2010) simulate Geo-grid in sand layers
loading plant by FE and compare it to the physical experiments. This research do
the original model by Liao's codes and add the grid in the model to do the loaded
plant test, then compare to Sawwaf's laboratory model.
The future research directions are for increasing the geo-grid in layer, and
simulate the lower friction of angle to discuss the result of Geo-grid, and use the
improved model to compare the bearing capacity.
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