| 姓名 | 何仁溫(Jen-Wen Ho) | 電子郵件信箱 | s9211604@mail.cyut.edu.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) | 沉泥質砂土中傾斜承拉式摩擦型地錨之三向度分析 | |||
| 論文名稱(英) | A Three Dimensional Study on the Inclined Shaft Tension Anchors in Silty 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/223 | |||
| 摘要(中) | 為探討沉泥質砂土中傾斜承拉式摩擦型地錨之錨碇行為，本文使用SHASOVOD模式(A Strain
Hardening-Softening and Volumetric Dilatancy
Model)配合FLAC3D軟體進行傾斜承拉式摩擦型地錨之三向度分析，並以現場試驗結果驗證數值分析結果之正確性。 由研究過程發現，傾斜承拉式摩擦型地錨之錨碇力主要係來自摩擦力。在相對密度Dr＝30%的沉泥質砂土中，發揮尖峰摩擦力所需之位移量約為35%D(D：地錨直徑)，達殘餘摩擦力之位移量約為65%D。 為避免傾斜地錨降伏範圍可能會發展至地表與結構壁體，本研究建議傾斜地錨之最小覆土深度Hmin應大於3m，最小埋入深度Zmin應大於2m。當相對密度較高或錨碇段長度較長，於地錨達極限拉拔力時，其降伏範圍也較大。而當相對密度提升時，降伏面呈更對稱的橢圓型；而增加錨碇段長度時，降伏面將呈較扁平的橢圓型。 無論是增加埋入深度、覆土深度或錨碇段長度皆可提升地錨之錨碇力，其中以增加錨碇段長度來提升錨碇力之效果為最佳，單位錨碇長度之錨碇力增量為55kN/m。但當錨碇段超過30m之後，其增加效果已呈低於線性之方式增加，此因地錨錨碇段周圍土壤的摩擦應力有漸進式降伏行為所致。當傾斜角度、埋入深度、覆土深度或錨碇段長度增加時，尖峰摩擦力下之側向土壓力Kf均呈現減少的現象，且小於被動土壓係數，但大於靜止土壓力係數。 | |||
| 摘要(英) | A strain
hardening-softening and volumetric expansion model named “SHASOVOD” and
FLAC3D software were quoted to study the anchorage behavior of inclined
shaft tension anchors in silty sand. A field test program was conducted
to verify the applicability of the numerical program as well. It was found that the friction force dominates the anchorage capacity of a shaft tension anchor. Of anchors installed in silty sand with relative density Dr of 30%, an anchor displacement of 35% D (D is the diameter of an anchor) is needed for the shaft friction reaches peak value, shaft friction approaches residual state at an anchor displacement of about 65% D. It could avoid the yielding zone of an anchor develops to ground surface and structural wall, when the overburden depth and embedded depth are greater than 3m and 2m, respectively. As relative density of soil or fixed length of an anchor increased, the yielding zone also expanded when the anchor was stressed to ultimate load. A more symmetric elliptical yielding zone surround an anchor was found when relative density of sand increased, whereas a more flatter elliptic yielding zone can be seen while increasing fixed length of an anchor. Whether embedded depth, overburden depth or fixed length of an anchor increased, the anchorage capacity also increased. Increasing fixed length should be the optimum method to increase the anchorage capacity, ultimate load perunit fixed length was about 55kN/m. However, when the fixed length of an anchor is greater 30m, the incremental of anchorage capacity per unit fixed length was decreased due to progressive yield of friction stress along fixed end. According to the numerical results, when the inclination angle, overburden depth, embedded depth, or fixed length increased, the coefficient of lateral earth pressure Kf decreased. The coefficient Kf always less than the coefficient of passive earth pressure Kp; however, it was greater than the coefficient of earth paessure at rest K0. | |||
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