粉質砂土中傾斜縱向三支排列群錨之受力行為

地錨經常被利用地工構物上，因此地錨受力行為的研究日益重要，國內外有不少學者探討地錨之受力行為。本研究利用數值分析探討粉質砂土中傾斜縱向三支排列群錨之受力行為，並利用鹿港-彰濱工業區現地試驗數值分析驗證程式之可行性。數值分析採用SHASOVOD模式(A Continuous Strain Hardening- Softening and Volumetric Dilatancy Model)模式與砂土力學參數，再以Fortran程式撰寫FLACfish語言，接著透過FLAC3D軟體進行分析。數值分析中發現，不管在任何參數下，當Sv =10D(D為地錨直徑)時幾乎不受群錨效應之影響。數值結果中顯示，垂直間距Sv =4D時群錨效益係數為85%；垂直間距Sv =10D時群錨效益係數為98%。研究亦發現垂直間距Sv =4D時，受群錨效應係數影響甚大，但垂直間距Sv =10D與群錨效應的影響幾乎消失。另外，傾斜縱向三支排列群錨之最小覆土深度建議為Hmin大於2m，最小埋入深度Zmin 建議大於2m，才可以避免傾斜群錨在施拉時，地錨周圍土壤降伏區發展至地表或結構壁體，而導致破壞。

關鍵字

數值分析；傾斜縱向三支排列群錨；粉質砂土；群錨效益係數

並列摘要

Ground anchors are usally to be served as earth structure. Therefore, the understanding of anchorage behavior is demanded. Numerous researches investigate the anchorage behavior of the anchors. This study adopts numerical method to investigate the anchorage behavior of three vertical-aligned inclined anchors in silty sand. The anchor test site is located at Jhangbin Industrial Park in Lugang, Changhua, and the test results are used to verify the applicability of the numerical method. The constitutive model named SHASOVOD (A continuous strain hardening-softening and volumetric dilatancy model) and the parameters needed for the model are adopted, in conjunction with FLAC3D software to carry out the numerical analyses. The numerical results reveal that no matter which anchor dimension is analyzed, when spacing between anchors is 10D (where D is the anchor diameter), the interference of the anchors virtually disappear. When anchor spacings are 4D, the efficiency is about 85%; when spacings are 10D, the efficiency is approximately 98%. As vertical spacing between anchors is 4D, the interference of anchors is evident; as the spacing is 10D, the interference vanishes. In addition, this study suggests that both the overburden depth and free length exceed 2m to avoid the yield zones develop to ground surface and/or to diagram wall.

並列關鍵字

Numerical analysis ； Three vertical-aligned inclined anchors ； Silty sand ； Efficiency of anchor groups

參考文獻

1. 廖瑞堂、陳昭維和陳御崇，「從地錨功能檢測經驗談坡地社區地錨管理維護機制」，技師期刊，第67期，第62~72 頁，2014。

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