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碩士論文公告區 |
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| 年度： | 96 | |
| 姓名： | 許博舜(Po-Shun Hsu) | |
| 論文題目(中)： | 粉土質砂土中擴座群錨之垂直受力行為 | |
| 論文題目(英)： | Uplift Behavior of the Underreamed Anchor Groups in Silty Sand | |
| 摘要(中)： | ||
| 本研究利用數值分析與現場試驗的方式探討粉土質砂土中擴座群錨之受力行為。數值分析的方式係經由現地採樣進行三軸試驗，利用SHASOVOD模式(A Continuous Strain Hardening/Softening and Volumetric Dilatancy Model)的構架，求取該模式所需之參數，再利用數值分析軟體FLAC3D進行擴座單錨與群錨之受力行為分析。此外，為驗證分析模式的適用性，本研究進行現地擴座單錨與群錨施工及拉拔試驗。於確認數值分析模式之可行性後，再進行不同條件下擴座單錨與群錨之參數研究。 由現地拉拔試驗之結果可發現，對直徑40cm、自由段10m、錨碇段5m的擴座單錨而言，位移量達11cm時，極限拉拔力約為650kN；而間距為160cm之2*2矩陣排列式群錨於平均位移量9.4cm時，極限拉拔力約為610 KN，而其群錨效應係數φ為94%。 由2*2矩陣排列之群錨發現無論是改變覆土深度或是錨碇段長度，當水平間距大於7.5倍地錨直徑時，可忽略群錨效應對錨碇力之影響；當覆土深度Z/D=5、水平間距Sh=2.5D(1m)時，其降伏面重疊且發展至地表；當水平間距大於5倍地錨直徑時，則降伏面並無發展至地表或重疊之現象。同時，由矩陣排列群錨之分析結果可發現3*3矩陣排列群錨受群錨效應之影響較2*2矩陣排列群錨還大。 |
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| 摘要(英)： | ||
| Both numerical analyses and field tests were accomplished to study the anchorage behavior of underreamed anchor groups in silty sand. A series of triaxial tests were performed on specimens taken from test site, based on the constitutive model of cohesionless soil named SHASOVOD (A continuous strain hardening- softening and volumetric dilatancy model), to obtained the parameters needed for the model. The model and the parameters were then quoted to evolve a numerical program by FORTRAN language, along with FLAC3D software to analyze behaviors of single anchors and anchor groups in silty sand. In addition, to verify the suitability of the numerical program, filed tests on a single underreamed anchors and an anchor group arranged in 2*2 matrix were conducted in silty sand. After the calibration, a succession of parameteric analyses was carried out to study the anchorage behaviors of single underreamed anchors and anchor groups in silty sand. It can be seen from the results of field test, an ultimate load of 650kN was estimated meanwhile the anchor head displacement reached 11cm for a single anchor with diameter of 40cm, free length of 10m, and fixed length of 5m; On the other hand the ultimate load of 610kN was measured with respect to the average of anchor head displacement of 9.4cm for a 2*2 anchor group with spacing of 160cm. Therefore, efficiency of an anchor group was computed to be 94%. It can be seen from the numerical results of 2 by 2 matrix-arranged anchors, no matter which it changes the fixed length or overburden depth, when the anchors were spaced was more than 7.5 times of anchor diameter D, it can eliminate the influence of anchorage capacity. Yield zone of soil develops to ground surface and it occurs superposition, when overburden depth of 5D and horizontal space of 2.5D (1m). The superposition of yielding zones will not be able to occur and the yield zone of soil will not develop to the surface when the anchors apart were spaced more then 5 D apart horizontally. Meanwhile, it can be found from the numerical results, the efficiency of 3*3 anchor group is greater than that of 2*2 anchor group. |
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| 檔案： | 沒有相關檔案 | |
| 相關連結： | http://ethesys.lib.cyut.edu.tw/ETD-db/ETD-search-c/view_etd?URN=etd-0826108-130309 | |