| 姓名 | 何思漢(Szu-han Ho) | 電子郵件信箱 | E-mail 資料不公開 | |
| 畢業系所 | 營建工程系碩士班(Department and Graduate Institute of Constrction Engineering) | |||
| 畢業學位 | 碩士(Master) | 畢業時期 | 92學年第2學期 | |
| 論文名稱(中) | 砂土中垂直擴座群錨之受力行為 | |||
| 論文名稱(英) | Uplift Behavior of Underreamed Anchor Groups in Sand | |||
| 檔案 |
請遵守中華民國著作權法之相關規定，切勿任意重製、散佈、改作、轉貼、播送，以免觸法。 |
論文使用權限 | 校內外完全公開 | |
| 論文語文/頁數 | 中文/279 | |||
| 摘要(中) | 本研究利用數值分析來探討緊砂中地錨在不同間距下之群錨效應與荷重位移關係。數值分析乃利用砂土之SHSE
(應變硬化-軟化與體積膨脹模式)模式配合FLAC3D軟體來進行地錨受力行為分析，並將雙錨於不同垂直間距之數值分析結果與模型試驗比較；此外，亦將群錨在不同水平間距下的數值分析結果與雙錨之受力行為進行比對，以瞭解砂土中垂直地錨錨碇力受間距之影響。 由研究結果顯示，於不同垂直間距下雙錨數值分析與模型試驗之結果相當接近。當固定水平間距於3D(D:地錨直徑)且下方地錨之覆土深度為10D時，上方地錨於垂直間距大於5.5D時可忽略群錨效應之影響；下方地錨於垂直間距大於7.5D時亦可免除群錨效應對地錨的影響。研究亦發現，下方地錨之摩擦力並不太受垂直間距之影響，而上方地錨之摩擦力卻有隨垂直間距減少而增加之趨勢。 由三支線型排列之群錨於不同水平間距下之研究結果顯示，當覆土深徑比分別為Z/D=4與Z/D=10且水平間距達7倍地錨直徑時，地錨可免除群錨效應之影響；當覆土深徑比Z/D達16時，在水平間距大於6倍地錨間距時，可忽略群錨效應對錨碇力之影響。在土壤降伏範圍高度重疊下，增加地錨支數無法有效提高地錨之錨碇力；本研究更進一步地由三支線型排列的地錨分析中發現，因緊砂受剪膨脹之因素，致使中間地錨之錨碇力有大於外圍地錨錨碇力之現象。隨著地錨間距之增加，土壤降伏範圍之重疊區域隨之減少，群錨間之錨碇力不再受群錨效應的影響，而使錨碇力趨近於單錨行為。 | |||
| 摘要(英) | A numerical study
has been performed to investigate the interactive behavior of
cylindrical anchor groups in dense sand. A constitutive model for sand
named “SHSE” and FLAC3D software were quoted to perform the numerical
analysis. To emphasize the applicability of the numerical model, the
results of laboratory anchor tests were used to verify the results of
numerical analyses for double anchors in different vertical space.
Moreover, the results of triple anchors placed in different horizontal
space are compared with the results of pair anchors. It was found that the load-displacement behaviors calculated by this numerical method were closed to the model anchor tests for pair anchors in different vertical space. When double anchors are placed 3D horizontally apart and overburden depth of the lower anchor equals to 10D, there will be virtually no interference if the vertical space equals to 5.5D and 7.5D(D: Diameter of an anchor) for an upper anchor and a lower anchor respectively. The numerical results indicate that there is no effect on friction force of a lower anchor; in addition, the friction force of an upper anchor increases as the vertical space of double anchors decreases. It can be seen from the numerical results of triple anchors ranked in a line and placed in different horizontal space, when overburden depth of anchors equal to 4D and 10D, there will be virtually no interference for total load if anchors are placed 7D horizontally apart. However, 6D horizontal space can eliminate the influence of anchorage capacity for triple anchors installed in the overburden depth of 16D. When yielding zone of soil around each anchor superposes highly, anchorage capacity of each anchor could not be increased effectively with increasing number of anchors. Moreover, according to the numerical results of triple anchors ranked in a line, the anchorage capacity of the middle anchor is greater than those of the others result from shearing dilation during anchors pulled out. The superposition of yield zones decrease as horizontal spaces increase. The behaviors of these triple anchors tend to independently as horizontal spaces increase to a critical value. | |||
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| 指導教授 |
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