臺灣博碩士論文加值系統

基樁受軸力長時間作用下，會產生側向持續變形行為，因此假若基樁之長細比過大，且基樁周圍土壤因潛變變形造成土壤剪力強度降低，不能提供足夠的剪力強度時，則有可能導致基樁潛變挫曲破壞。
由於基樁之潛變挫曲為動態行為，因此本文利用基樁受軸力與土壤互制之動態運動方程式，考慮基樁可能為鉸接或其他型式之邊界條件，並將樁體考慮為線彈性材料，而土壤以彈簧(Spring)及阻尼(Damping)組合之黏彈性模式來模擬，探討彈性基樁埋置於黏彈性土壤中，其受軸向力作用之下，基樁之潛變挫曲載重及樁身隨時間歷時變形的關係。利用拉普拉斯轉換(Laplace Transform)，可求出土壤考慮潛變後之楊氏模數或地盤反力模數及基樁之潛變挫曲載重。此外，基樁受軸力作用隨時間產生的側向變形，則利用動態觀念來分析。
本研究分析方法配合Kuppusamy et al. (1969)研究成果，與前人研究所得之實驗結果比較，研究成果顯示，利用本方法推估之潛變挫曲載重與實驗值接近，其值低於彈性挫曲載重而高於單一柱挫曲載重；由於基樁在長時間外力作用下之實驗數據較少，故未來仍須與更多實驗結果進行分析比較，作為本研究之佐證。

第一章 緒論……………………………………………………….. 1
1-1研究動機…………………………………………… 1
1-2研究方法…………………………………………….. 1
1-3論文內容…………………………………………….. 2
第二章 文獻回顧…………………………………………………. 3
2-1挫曲理論…………………………………………….. 3
2-2黏土潛變行為……………………………………….. 8
2-3黏土潛變法則……………………………………….. 9
2-4潛變造成土壤強度降低的原因…………………….. 11
2-5土壤參數…………………………………………….. 12
第三章 理論推導…………………………………………………. 14
3-1黏彈性材料組成律………………………………….. 14
3-2潛變柔度函數與鬆弛模數………………………….. 18
3-3核函數……………………………………………….. 19
3-4基樁受軸向力與土壤互制運動方程式…………….. 20
3-5基樁潛變挫曲載重之推導………………………….. 21
3-5-1水平地盤反力係數為常數者…………………. 21
3-5-2水平地盤反力係數呈線性變化者……………. 24
3-6變形量探討………………………………………….. 25
3-6-1正確解………………………………………….. 26
3-6-2近似解………………………………………….. 27
第四章 數值分析…………………………………………………. 29
4-1彈性挫曲分析……………………………………….. 29
4-2潛變挫曲分析……………………………………….. 30
4-3不同邊界條件對潛變挫曲載重之影響…………….. 31
4-4基樁變形參數探討………………………………….. 33
第五章 結論與建議………………………………………………. 35
5-1結論………………………………………………….. 35
5-2建議………………………………………………….. 36
參考文獻…………………………………………………………….. 37

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