粉質砂土中水平排列群錨之受力行為

Horizontal Spacings Effects on the Anchorage Behavior of Inclined Anchor Groups in Silty Sand

馬維揚(Wei-Yang Ma)

指導教授 ： 許世宗

朝陽科技大學/理工學院/營建工程系/碩士(2015年)

摘要

本研究利用現地試驗與數值分析的方式探討雙錨與群錨之受力行為。數值分析的方式係利用三軸試驗結果，套用SHASOVOD模式(A Continuous Strain Hardening Softening and Volumetric Dilation Model)的架構，求取該模式所需之參數，再利用數值分析軟體FLAC3D進行單錨與群錨之受力行為分析。並以現場地錨試驗結果驗證數值分析之正確性，以瞭解雙錨及群錨之錨碇行為。
由數值分析發現，對於雙錨及群錨四支，水平間距Sh=4D (D：地錨直徑)時，群錨效益係數僅約74-78%，顯示其受群錨效應影響甚大；但水平間距水平間距Sh=10D時，群錨效益係數僅約96%-99%，幾乎不受群錨效益影響，由四支線性排列傾斜群錨研究發現，在平間距Sh=4D (D：地錨直徑)時，內部地錨群錨效益係數約68%，外側地錨群錨效益係數約78%，群錨效益係數平均為73%，相較之下中心地錨明顯較小，可能是因為在中心地錨部分降伏區域重疊較多所造成。地錨支數越多，群錨效應越顯著。

關鍵字

三向度分析 ； 群錨效應 ； 粉質砂土 ； 傾斜地錨

並列摘要

To evaluate the uplift behavior of paired and four-aligned inclined friction anchors in silty sand, a series of triaxial test results were utilized to obtain the parameters needed for the continuous strain hardening-softening and volumetric dilation model, SHASOVOD. In conjunction with FLAC3D, a numerical study was carried out to analyze the behavior of dual and four-aligned inclined friction anchors in silty sand. A field test program was conducted in silty sand within an excavating site to verify the applicability of the numerical program. Finally, parametric studies on the factors affecting the anchorage behavior were executed.
According to the numerical results, when the paired & four-aligned anchors installed in silty sand with a spacing Sh of 4D (D is the anchor diameter), the efficiency of the anchor group was calculated to be approximately 74-78%. As the Sh equaled 10D, the efficiencies of an anchor group exceeded 96%-99%. When the four-aligned anchor installed in silty sand with spacings Sh of 4D, the efficiency of the inside anchors in the anchor group was calculated to be approximately 68%; however, the efficiency of the outside anchors in the anchor group was 78%； an average efficiency of 73% was found in this study. The pullout force of the inside anchors was smaller than that of the outside anchor, because yielding soils overlap around inside anchors exceeded those of outside anchors. The more the anchors installed in a group, the more the interference occurs in the anchor group.

並列關鍵字

Efficiency of an anchor group ； Silty sand ； Inclined anchor ； Three-dimensional analysis

參考文獻

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