非飽和紅土K0 壓密行為之研究

K0 Consolidation Behavior of Unsaturated Lateritic Soil

陳家豪(Chia-Hao Chen)

指導教授 ： 魏敏樺

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00478

摘要

Terzaghi（1943）提出飽和土一維壓密的經典理論，詳細說明土壤滲流對於土壤沈陷之影響，至今已有相當成熟技術發展與應用，並且成功解決關於地工結構物加載所產生的地表沈陷問題。但對於非飽和土壤領域之壓密行為目前卻鮮少被人提及。 本研究為探討林口紅土非飽和壓密行為，將非飽和三軸系統加以改良，內部使用壓密鋼環束制試體，使試體能處於K0 狀態下進行非飽和壓密。整組非飽和K0 壓密試驗是將常含水量試驗、壓密試驗，增加基質吸力試驗相互串連循環而成，可探討基質吸力與垂直載重交互作用下，非飽和紅土K0 壓密時之水體積、土體積變化。且利用非飽和一維壓密理論，預測非飽和K0 壓密之土體積變化與水體積變 化，再與實驗值結果加以對照。另外觀察常含水量試驗法，可提供不同基質吸力的孔隙水壓的激發資訊，瞭解基質吸力與孔隙水壓參數Bw 之關係。 為了進一步瞭解非飽和紅土K0 壓密之靜止土壓力係數變化，故在壓密鋼環上黏貼應變計，利用電壓與應力關係求得試體側向土壓力變化。並使用前人所提議之非飽和K0 模型，來預測本試驗研究之K0 變化，探討二者K0 模型與實際量測K0值之差異。

關鍵字

K0 壓密 ； 靜止土壓力係數非飽和土壤 ； 壓密係數基質吸力

並列摘要

Terzaghi’s one-dimensional consolidation theory that relates pore water pressure to settlement has been successfully applied to saturated soil. However, the use of this theory to unsaturated soil has rarely even been discussed. In this study, unsaturated K0 consolidation experiments that involved constant water content test, consolidation testand increase of matric suction test have been used to investigate the changes in water and soil volumes change of unsaturated lateritic soil. The experiments were conducted in an oedometer-type ring placed in an advanced triaxial apparatus for unsaturated soils.
The one-dimensional consolidation theory was then used to compare and contrast the experimental resutl. Good agreement has been obtained between the two sets of result.

並列關鍵字

K0-consolidation ； coefficient of earth pressure at rest ； unsaturated soil ； matric suction

參考文獻

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[7]Barden, L. (1965). "Consolidation of Compacted and Unsaturated Clays." Geotechnique, 15(3), 267-286.