臺灣博碩士論文加值系統

台灣由於地狹人稠，土地資源有限，尤其在都市地區人口眾多且地價昂貴，許多建築物紛紛往高空發展，為了增加結構物的穩定性，樁基礎的使用也越來越多。又臺灣地屬於環太平洋火山地震帶西側為易發生地震的地區，故研究樁基礎的受振反應對安全上有一定的重要性。本研究利用離心模型試驗的尺度定律，進行80倍重力場的離心模型縮尺，模擬樁基礎埋置於乾砂土層中，受地震力作用的樁身反應，在此原則下設計並建造樁基礎的縮尺模型。配置具有三種不同上部結構物(L-Pile、M-Pile及S-Pile)，並輸入預定的振動事件。為探討樁基礎的受振行為，必須取得土壤及樁基礎的動態參數，於樁基礎模型及周圍的土層中裝設各型的感測器陣列，瞭解樁基礎及土壤受振過程加速度歷時，同時在受振過程中，利用應變計量測樁體在不同深度及不同瞬時之樁身彎矩，求取樁身沿深度的剪力、土壤反力與變位，藉此分析樁身因受土壤反覆作用力下之變位分析。其中，樁基礎S-Pile即檢視上部結構物之貢獻大小，藉由試驗結果探討樁基礎的受振反應。
結果顯示，基樁受振時，L-Pile與M-Pile之最大彎矩量皆發生在土表下1.6 m (z/Dp=1.26) 處，而無上部載重之樁基礎S-Pile則分佈於土表下4.8 m~14.4 m (z/Dp=3.8~11.3) 處。當樁基礎其系統主頻與地震頻率相近時會發生共振效應，彎矩最大值發生於第7~10個週數，而系統主頻與地震頻率相差較遠時，彎矩最大值發生在第1~3個週數且為負彎矩；S-Pile易受到土壤變位影響，彎矩最大值較無規律。M-Pile (27.6 m) 及S-Pile (25.2 m) 有無樁頭載重(133 ton)的條件下，S-Pile的樁身彎矩僅M-Pile的10%；L-Pile (35.4 m)與M-Pile (27.6 m)具相同載重，當上部結構重心較高時，低頻地震產生的樁身彎矩比高頻地震大，重心較低則反之。從土壤側向變位可知，S-Pile樁身彎矩與土壤變位有關；藉地表樁身彎矩可知，L-Pile的地表樁身彎矩主要受牛頓運動定律(Newton’s law)影響；M-Pile的地表樁身彎矩主要受轉動慣量(moment of inertia)影響。

There is limited plate land but too much population in Taiwan, so the area and price of land at city is very expensive. Therefore, skyscraper were often built in recent year. Taiwan locates at the west side of the Circum-Pacific seismic zone, earthquakes often occur in this area. In order to increase the stability of the structure, the moment response of pile foundation is getting more important. Three kinds of piles (L-Pile, M-Pile and S-Pile) arranged for four centrifuge modeling tests which were performed in an artificial acceleration field of 80 g. The response of pile foundation were simulated by physical modeling and the seismic loadings were applied by centrifuge shaking table. The prototype pile foundation was scaled to design the model pile, and it is reduced to 1/80 times in dimension to the centrifuge model. Three accelerometer arrays were installed in the soil layer to measure the acceleration histories during shaking. The response of bending moments along the pile would be obtained from the attached strain gauges. The rotation angle and deflection of pile along depth can be calculated. Especially, the S-Pile which without upper structure to investigate the contribution from pile head loading.
Test results show that the frequencies of L-pile (with 10.8 m height of upper structure and mass of 1330 kN), M-pile (with 2.8 m height of upper structure and mass of 1330 kN) and S-pile (without upper structure) are 0.65 Hz, 1.99 Hz and 2.23 Hz, respectively. The soil resistance increases with the increasing depth for all models.　The maximum bending moments of L-pile and M-pile occurred at 1.6 m (z/Dp=1.26, D is the diameter of pile) underground surface, and there is almost no significant bending moment along S-pile (z/Dp=3.8~11.3); the bending moments of L-Pile, M-Pile and S-Pile caused by Newton’s law, moment of inertia and soil displacement, respectively (L-Pile>M-Pile, 0.1×M-Pile≥S-Pile).

摘要 i
Abstract ii
誌謝 iv
目錄 v
圖目錄 viii
表目錄 xiv
圖附錄 xv
符號說明 xix
第一章 緒論 1
1-1前言 1
1-2研究動機與目的 1
1-3研究方法 1
1-4論文架構 2
第二章 文獻回顧 3
2-1基樁受振行為 3
2-2離心模型原理 4
2-2-1離心模型之基本相似律 5
2-2-2動態離心模型之基本相似律 5
2-2-3科氏加速度影響 6
2-2-4模型模擬(modeling of models) 7
2-3國內設計規範 8
2-4美國石油協會(API)建議之p-y曲線 8
2-5土層的彈性模數 9
第三章 試驗方法與試驗設備 19
3-1 試驗方法 19
3-2試驗土樣及基本性質 19
3-3 儀器設備與相關設備 20
3-3-1 地工離心機 20
3-3-2 中大離心振動台與資料擷取系統 20
3-3-3積層版試驗箱 21
3-3-4樁基礎模型 21
3-3-5各式感測器 22
3-3-6移動式霣降機 23
3-4試驗準備步驟與流程 24
3-4-1 前置作業 24
3-4-2重模試體製作 24
3-4-3離心機繞行前準備與振動試驗 25
第四章 試驗結果與分析 44
4-1 試驗規劃與條件 44
4-2 試驗結果 46
4-2-1 Ltest1之試驗結果 46
4-2-2 Mtest2之試驗結果 52
4-2-3 Ltest3之試驗結果 57
4-2-4 Mtest4之試驗結果 62
4-2-5 小結 67
4-3 綜合討論 69
4-3-1 加速度放大倍率 69
4-3-2 基盤與樁頭之相位差 70
4-3-3 樁基礎之旋轉角 71
4-3-4 樁基礎於各事件之最大彎矩值 72
4-3-5 L-Pile與M-Pile於土表之樁身彎矩歷時 73
4-3-6 樁身彎矩與土壤側向位移 74
4-3-7 水平地盤反力係數 74
第五章 結論與建議 210
5-1 結論 210
5-2 建議 211

[1]. API, “Recommended practice for planning, designing, and construction fixed offshore platforms-working stress design,” 2000.
[2]. Barbara J.C., Tara, C.H., “Experimental investigation of plastic demands in piles embedded in multi-layered liquefiable soils,” Soil Dynamics and Earthquake Engineering, Vol. 49, pp. 146-156 (2013).
[3]. Bhattacharya S.,“Pile Instability during earthquake liquefaction,” Ph.D Dissertation, University of Cambridge, Cambridge, UK (2003).
[4]. Finn, W. D. L., and Fujita, N., “Piles in liquefiable soils:seismic analysis and design issues,” Soil Dynamics and Earthquake Engineering,Vol.22, No. 22, pp.731-742 (2002).
[5]. Lee, C.J., Hung, W.Y., Tsai, C.H., Chen, T., Tu, Y.C., Huang, C.C., “Shear wave velocity measurements and soil-pile system identifications in dynamic centrifuge tests,” Bulletin of Earthquake Engineering, Vol. 2, pp.717-734 (2014).
[6]. Lee, C.J., Wang, C.R., Wei,Y.C., and Hung, W.Y., “Evolution of the shear wave velocity during shaking modeled in centrifuge shaking table tests,” Bulletin of Earthquake Engineering, Vol. 10, No.2, pp.401-420 (2012).
[7]. Lee, C.J., Wei, Y.C., Kou, Y.C., “Boundary effects of a laminar container in centrifuge shaking table tests,” Soil Dynamics and Earthquake Engineering, Vol.34, No. 1, pp.37-51 (2012).
[8]. Reese, L.C., and Matlock, H., “Non-dimensional solutions for laterally loaded piles with soil modulus assumed proportional to depth,” Proceedings of the Eighth Texas Conference on Soil Mechanics and Foundation Engineering, University of Texas, Austin, Texas (1956).
[9]. Terzaghi, K., “Evaluation of Coefficients of Subgrade Reaction,” Geotechnique, Vol. 5, No. 4, pp.297-326 (1955).
[10]. Tokimatsu K., Suzukia S., and Sato M., “Effects of Inertial and Kinematic Interaction on Seismic Behavior of Pile with Embedded Foundation,” Soil dynamics and earthquake engineering, Vol.25, pp.753-762 (2005).
[11]. Hung, W.Y., Lee, C.J., Chung, W.Y., Tsai, C.H., Chen, T., Huang, C.C., Wu, Y.C., “Centrifuge Modeling on Seismic Behavior of Pile in Liquefiable Soil Ground,” Applied Mechanics and Materials, Vol.479-480, pp. 1139-1143 (2014).
[12]. Yoo, M.T., Choi, J.I., Han, J.T., Kim, M.M., “Dynamic P-Y Curves for Dry Sand from Centrifuge,” Journal of Earthquake Engineering, Vol. 17, pp. 1082-1102 (2013).
[13]. 王崇儒，「利用彎曲元件探查離心砂土模型剪力波波速頗面及其工程上的應用」，碩士論文，國立中央大學土木工程學系，中壢 (2010)。
[14]. 中華民國大地工程學會，建築物基礎構造設計規範，中華民國 (2001)。
[15]. 日本道路協會，道路橋示方書‧同解說，日本 (1996)。
[16]. 呂振榮，「以動態離心模型試驗模擬可液化地盤中離岸風機單樁基礎之受振反應」，碩士論文，國立中央大學土木工程學系，中壢 (2014)。
[17]. 呂昕澔，「以離心模型模擬離岸風機單樁受反覆水平側推行為」，碩士論文，國立中央大學土木工程學系，中壢 (2014)。
[18]. 吳宇浩，「液化地盤群樁基礎地震反應之模擬」，碩士論文，國立中央大學土木工程學系，中壢 (2014)。
[19]. 林郁庭，「以離心模型模擬離岸風機單樁受反覆水平側推之p-y曲線」，碩士論文，國立中央大學土木工程學系，中壢 (2013)。
[20]. 邱益增，「加勁土堤受振反應之離心模型試驗」，碩士論文，國立中央大學土木工程學系，中壢 (2012)。
[21]. 涂亦峻，「位於可液化砂土層中單樁基礎受振反應的離心模擬」，碩士論文，國立中央大學土木工程學系，中壢 (2011)。
[22]. 郭玉潔，「探討基層版試驗箱進行動態離心模型試驗之邊界效應」，碩士論文，國立中央大學土木工程學系，中壢 (2009)。
[23]. 張有齡、周南山，「張氏簡易側樁分析法(上篇：靜力部份)」，地工技術，第25期，第64-82頁(1989)。
[24]. 歐晉德，「基樁之側向支承力」，地工技術，第18期，第60-68頁 (1987)。
[25]. 鄺柏軒，「利用動態離心模型試驗模擬砂土層之剪應力與剪應變關係」，碩士論文，國立中央大學土木工程學系，中壢 (2010)。