本研究針對兩種典型箱籠牆面配置之加勁土擋土牆（牆面垂直式、牆面台階式）進行參數研究。其中，涉及之數值變數包括牆背回填土摩擦角?痋]=20。∼35。）、牆背回填土之彈性模數Eb（=103∼105kpa）以及基礎表土層之彈性模數Ef（=103∼105kpa），以檢核牆背回填土及基礎表土層材料特性，對牆體變形行為及金屬線格網加勁材抗拉力發展的影響。
研究發現，箱籠牆面六邊形金屬線格網加勁擋土結構其加勁材所發展之最大拉力，在下層區較上層區者為大，可歸因於牆體下層區鄰近趾部牆面發生鼓突式的變形，此變形模式導致下層區之加勁材承受較大的拉力；另外，對同一高程之加勁材而言，加勁材發展之最大抗拉力隨回填土內摩擦角?祤W大而減小，原因可推測為牆面所受之土壓力隨?眹兮W加而減少所致。因此提高回填土內摩擦角?痋A確可降低牆面之水平土壓力，並可減緩牆體變形及加勁材之拉力。
另由數值分析結果可得知，回填土彈性模數範圍在103∼104kpa時，對牆體變形及加勁材拉力計算最大值有相當的影響；然而，當彈性模數超過104kpa時，牆體變形及加勁材拉力之變異將不再明顯。
再者，基礎土層彈性模數Ef由104降為103kpa時，對垂直式牆面而言，其牆面最大水平變形量由26.5mm增加至117.8mm；對於台階式牆面，則由20.9mm提高至89.0mm。研究發現基礎土層彈性模數為影響土層沉陷之重要因子，控制牆體剛體移動及內部變形，因此牆體垂直變形及加勁材最大拉力深受土層彈性模數Ef的影響。
又經觀察數值模擬牆體變形結果得知，基礎土層經過排水壓密後，牆體由於地表發生大量沉陷而扭曲變形，並導致牆體內配置之加勁材隨牆體的後仰而收縮，因此與地層未排水壓密之情況比較，其加勁材承受之拉力反而變小；另外，牆體後仰的移動分量，將使作用之土壓力由主動狀態轉換成被動狀態，造成土壓力有增加的趨勢。In this study, a series of parametric study was conducted on two types of Gabion Wall Reinforced Earth Structure (GWRES) reinforced with hexagonal wire mesh, namely, the vertical wall type and step wall type. The numerical variables adopted for parametric study includes the internal friction angle of backfill materials ??(=20o~35o), elastic modulus of backfill material Eb (=103~105 Kpa) and elastic modulus of top foundation soil Ef (=103~105 Kpa).
According to the analysis, it was found that the developed tensile force in reinforcement at bottom zone of GWRES is higher that at the top zone. This is due to the bulged type of lateral wall movement frequently occurred at the bottom zone of GWRES. However, for reinforcement installed at a specific level, the tensile force decreases with the increasing internal friction angle of backfill material ??and this can be inferred from the fact of the reduce of lateral earth pressure.
In addition, the numerical results indicated that the elastic modulus of backfill material Eb in the range of 103~104 Kpa may cause significant effect on the wall movement and the development of tensile force of reinforcement in GWRES. On the contrary, as the magnitude of Eb value is higher than 105 Kpa, the variation of wall movement and distribution of tensile force of reinforcement appears not obvious. On the other hand, as the elastic modulus of top foundation soil Ef decreases from 104 to 103 Kpa, the maximum lateral wall movement might increase from 26.5 mm (20.9mm) to 117.8mm (89.0mm) for vertical wall type (step wall type) of GWRES respectively. This implies that the stiffness of foundation soil layer is one of the most crucial factor dominates the rigid motion and internal deformation of GWRES. Alternately, the wall settlement and the tensile force of reinforcement are significantly influenced by the stiffness of foundation soil layer immediately beneath the GWRES.
Finally, it was observed that the consolidation settlement of foundation soft soil always results in an enormous distortion on GWRES. As a consequence, the tensile force in reinforcement might decrease due to the shrinkage of reinforcement caused by the backwards overturning of GWRES.摘要．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．Ⅰ ABSTRACT．．．．．．．．．．．．．．．． ．．．．．．．．．．．．Ⅱ
目錄．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．Ⅲ
表目錄．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．Ⅴ
圖目錄．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．Ⅵ
第一章 引言．．．．．．．．．．．．．． ．．．．．．．．．．．．．1
1.1 概述．．．．．．．．．．．．． ．．．．．．．．．．．．1
1.2 問題陳述．．．．．．．．．．． ．．．．．．．．．．．．1
1.3 研究目的．．．．．．．．． ．．．．．．．．．．．．．．1
1.4 研究範圍．．．．．．．． ．．．．．．．．．．．．．．．1
第二章 文獻回顧．．．．．．．．．．．．． ．．．．．．．．．．．．2
2.1 沿革．．．．．．．．．．．．．． ．．．．．．．．．．．2
2.2 箱籠．．．．．．．．．．．．．．．． ．．．．．．．．．2
2.3 二維有限元素程式-PLAXIS．．．．． ．．．．．．．．．．4
2.3.1 概述．．．．．．．．．． ．．．．．．．．．．4
2.3.2 理論背景．．．．．．．．．． ．．．．．．．．4
2.3.3 元素類型（element types）．．．．．．．．．．．5
2.3.4 材料組合律或組合模式（constitutive law 或constitutive model）．．．．．． ．．．．．．．．7
2.3.5 Mohr-Coulomb模式參數之決定原則． ．．．．．11
2.3.6 Soft Soil模式參數之決定原則．．．．．．．．．12
2.4 影響加勁土力學與變形行為之因素．．．．．．．．．．．．13
2.4.1 牆面系統之連續性（continuity）．．．．．．．．13
2.4.2 牆面系統之剛性（rigidity）．．．．． ．．．．．13
2.4.3 回填材料之彈性模數．．．．．．．．．．．．．15
2.4.4 基礎層之彈性模數．．．．．．．．．．．．．．16
2.4.5 回填材料與加勁材間之界面強度．．．．．．．．17
第三章 研究流程．．．．．．．．．．．．．．．．．．．．．．．．．19
3.1 概述．．．．．．．．．．．．．．．．．．．．．．．．．19
3.2 數值模擬．．．．．．．．．．．．．．．．．．．．．．．19
3.2.1 數值變數（Numerical Variable）．． ．．．．．．24
3.2.2 離散化幾何模型與材料組合模式．．．．．．．．24
3.2.3 施工過程數值模擬．．．．．．．．．．．．．．25
第四章 結果與討論．．．．．．．．．．．．．．．．．．．．．．．．27
4.1 概述．．．．．．．．．．．．．．．．．．．．．．．．．27
4.2 數值變數對牆體之影響．．．．．．．．．．．．．．．．．27
4.2.1 回填土摩擦角．．．．．．．．．．．．．．．．27
4.2.2 回填土彈性模數．．．．．．．．．．．．．．．48
4.2.3 基礎土層彈性模數．．．．．．．．．．．．．．49
4.2.4 基礎土層壓密．．．．．．．．．．．．．．．．52
第五章 結論與建議．．．．．．．．．．．．．．．．．．．．．．．．57
5.1 結論．．．．．．．．．．．．．．．．．．．．．．．．．57
5.2 建議．．．．．．．．．．．．．．．．．．．．．．．．．57
參考文獻．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．5
