以現場試驗與數值分析探討粉質砂土中 水平線性排列群錨之受力行為

Experimental and Numerical Studies on the Behavior of Horizontally Aligned Anchor Groups in Silty Sand

詹凱仁(KAI-JEN CHAN)

指導教授 ： 許世宗

朝陽科技大學/理工學院/營建工程系/碩士(2016年)

摘要

地錨已被廣泛應用在大地工程上，且大多以群錨方式呈現，特別是傾斜地錨。本文採用數值分析方式探討粉質砂土中水平線性排列傾斜地錨之受力行為，再以現地拉拔試驗驗證數值分析的正確性，再進行影響參數探討。數值分析係採用SHASOVOD模式（A Continuous Strain Hardening-Softening and Volumetric Dilatancy Model）的架構與相關砂土力學參數，配合FLAC3D軟體進行傾斜雙錨與四支線形排列群錨之受力行為分析。本研究的數值分析在利用現地群錨試驗結果驗證後，針對不同覆土深度、埋入深度、錨碇段長度及水平間距進行探討。
研究過程中發現，現場試驗結果與數值分析結果一致。傾斜雙錨在水平間距為4D (D：地錨直徑)時群錨效益係數為78%；四支線形排列群錨則為72%，群錨的支數愈多，群錨效應愈明顯。自由段長度與覆土深度對群錨效益係數影響極為有限。本研究，不論在何種條件下，當地錨水平間距達到10D，可大致不受群錨效應的影響。

關鍵字

數值分析 ； 傾斜水平排列群錨 ； 粉質砂土 ； 群錨效益係數

並列摘要

Anchors are extensively applied in geotechnical area, and are usually adopted in a group, especially the inclined anchors. This study adopted the numerical method to investigate the anchorage behavior of horizontally aligned inclined anchor groups in silty sand, the numerical results were verified by in-situ results, after that, this research carried out a series of parametric studies. Based on the SHASOVOD model (A continuous strain hardening- softening and volumetric dilatancy model) and the parameters of sandy soil needed for this model, this study employed the FLAC3D software to analyze the behavior of dual and four horizontally aligned anchors. After numerical results calibrated by experimental results, this study conducted parametric studies, such as the overburden depth, free length, anchorage length and horizontal spacing.
Numerical results show that the load-displacement behaviors calculated numerically are consistent with those measured by anchor tests. When the spacing between neighboring anchors is 4D for dual anchors and four-aligned anchor group, the efficiency of an anchor group are 78% and 72%. The more the installed in a group, the more the interference occurs. The effect of the free length and overburden depth on the efficiency of an anchor group is infinitesimal. The behavior of each anchor in the anchor group is virtually identical to the behavior of a single anchor when the horizontal spacings exceed 10D.

並列關鍵字

Numerical analysis ； Inclined aligned anchor ； Silty sand ； Efficiency of anchor group

參考文獻

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