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題 名 | 應變速率對過壓密重模性土壤剪力強度之研究=Strain Rate Effect Upon Undrained Shear Strength of Remolded Overconsolidated Clays |
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作 者 | 徐登文; 董文魁; 陳育志; | 書刊名 | 中國土木水利工程學刊 |
卷 期 | 10:4 1998.12[民87.12] |
頁 次 | 頁803-808 |
分類號 | 441.12 |
關鍵詞 | 應變速率; 剪力強度; 重模性黏土; 三軸壓密不排水剪力試驗; Strain rate; Shear strength; Remolded clay; Consolidated-undrained triaxial compression test; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究乃探討過壓密之重模性黏土在不同等軸向應變速率下對剪力強度行為之 影響。以直徑 2in. 高為 4in. 之試體,在三種不同的塑性指數 PI=8、18 及 28 下,分別 以四種等應變速率 3%/min、 1%/min、0.1%/min 及 0.01%/min 下進行一系列三軸壓密不排 水剪力試驗。結果顯示:剪力強度隨應變速率之增加而增加,且對 PI 較大之試體影響較大 ,同時其間成半對數之直線關係,此直線斜率 n 隨試體液性指數 LI 之增加而減少。 同時 亦發現過壓密比 OCR 較高者在 PI 較大之試體中速率對剪力強度之影響較 OCR 小者為明顯 。 OCR 較低且 PI 較大者在較快速率下於試體端點量測的孔隙水壓在低應變時較慢速率為 小,此乃孔隙水壓於高速率下在過壓密土壤中較不易排出,但 PI 較小者孔隙水壓對速率之 影響則不顯著。 對過壓密比 OCR 較大之試體在大應變時於快速率試驗中,具有較小負值之 孔隙水壓,此種情形尤其發生於 PI 較大之試體。 |
英文摘要 | This paper presents the strength behavior of remolded overconsolidated clays sustaining various rates of strain. Undrained triaxial compression tests were performed on three types of cohesive soils with different plasticity index (PI). The results indicate that the strain rate has little effect on the shear strength of specimens with low PI. However, specimens with high PI do reflect significant strain rate effects. The data also indicate a linear relationship between the undrained shear strength and strain rate on a semi-log scale. The slope n of this linear relationship decreases with liquidity index and increases with overconsolidation ratio. Under a high strain rate, the excess pore pressures measured measured in the high PI specimens were found to be lower compared with the case of low strain rate at low strains, while little difference was encountered in the low PI specimens. This may be due to the high consolidation coefficient exhibited in the low PI specimens resulting in a rapid pore water pressure dissipation. |
本系統中英文摘要資訊取自各篇刊載內容。