| 姓名 | 林鈺恆(Yu-Heng Lin) | 電子郵件信箱 | yhlin0806@yahoo.com.tw | |
| 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 | 93學年第2學期 | |
| 論文名稱(中) | 層狀土壤中承拉式摩擦型地錨之受力行為 | |||
| 論文名稱(英) | Uplift Behavior of Shaft Tension Anchors in a Layered Soil | |||
| 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/209 | |||
| 摘要(中) | 本文以台北盆地之層狀土壤中承拉式摩擦型地錨為研究對象，利用砂土與粘土三軸試驗結果，套用應變硬化-軟化與體積膨脹模式(SHASOVOD模式)，求取SHASOVOD模式所需之參數，進行層狀土壤中承拉式摩擦型地錨之數值分析，並以現地地錨試驗結果驗證數值分析之正確性。最後，本研究進行各項地錨影響參數之研究，以瞭解層狀土壤中承拉式摩擦型地錨之受力行為。 經驗證結果得知，本研究所撰寫之分析程式對於層狀土壤中承拉式摩擦型地錨之模擬可得到良好的結果。由研究結果顯示，隨著地下水位升高地錨錨碇力將會降低；錨碇於基礎版之垂直地錨在開挖深度大於5m後，錨碇力將不太受過壓密比的影響而趨於定值。將現地層狀土壤簡化成單層土壤來計算地錨之錨碇力其誤差不大。但在層狀土壤中的地錨宜採用雙層保護，以免水泥漿體開裂，造成鋼絞線銹蝕，影響地錨的長期錨碇力。地錨之拉拔力隨著SPT-N值、覆土深度、錨碇段長度及地錨直徑的增加而提高，其中又以增加地錨錨碇段長度的效果最佳，直徑12cm之地錨單位錨碇長度地錨錨碇力增量約為45kN/m。 對於直徑為12cm之地錨而言，當錨碇段長度大於25m後，在相同地錨總長度下，增加地錨錨碇段長度無法有效地增加地錨錨碇力。承拉式地錨之荷重傳遞方式係由錨頂向錨底傳遞，且當錨碇段長度大於30m後，地錨周圍土壤的摩擦應力將產生漸進式降伏。 | |||
| 摘要(英) | To evaluate the
uplift behavior of shaft tension anchors in a layer soil, a constitutive
model for a strain hardening-softening of dilated soil named SHASOVOD
was quoted, a series of triaxial CID and CIU tests on clay and sand were
performed to obtain the parameters needed for the soil model. A
numerical program was written based on the model and the parameters,
together with FLAC software to study the uplift behavior of shaft
tension anchors in a layer soil of Taipei basin. To emphasize the
applicability of the numerical model, the results obtained from the
field tests were conducted to verify those of numerical analyses. After
the verifications, parametric studies on the factors affecting the
anchorage behavior of shaft tension anchors were performed. It was found, that the calculated load-displacement curves of test anchors are close to those measured from the field tests. The higher elevations of ground water table the less anchorage capacity. For a vertical anchor which was anchored on foundation mat, the effect of over consolidation ratio on anchorage capacity was not evident, when depth of excavation was greater than 5m. There is not much distinction on anchorage capacity between an anchor installed in a pure soil and a layer soil, if their average SPT blow counts are equal. However, when an anchor was located in a layer soil, the friction stress occurs discontinue behavior, the double protection should be used in fixed length for keeping long term anchorage capacity. Whether SPT blow count, overburden depth, fixed length or diameter of an anchor increased, the anchorage capacity also increased. Increasing fixed length should be the optimum method to increase the anchorage capacity. The increment of ultimate load per unit fixed length was estimated to be 45 kN/m for an anchor with diameter of 12cm. According to the numerical results for anchors with diameter of 12cm, increasing fixed length could not increase the ultimate load, when the fixed length of anchors greater than 25m and the total length were fixed. The load transfer from top toward bottom of a tension anchor, the friction stress along the fixed anchor end shows a progressive yielding behavior as fixed length of an anchor greater than 30m. | |||
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