- 作者: 李建中; 鄭清江
- 作者服務機構: 國立中央大學土木工程研究所
- 中文摘要: 國內目前正規畫在西海岸開發許多離島工業區及海埔新生地,且大部份擬採用抽取附近海床砂土來填築。因此有關水力填築技術及相關之大地工程問題將成為當前重要之研究課題。 本研究運用過程模擬方式製作了水力輸砂儀,以作為試驗用片狀砂土的模擬水力輸砂試體之準備方式。針對此種模擬試體沈積過程中之行為做詳細探討,最後並以沈積完成之試體,進行片狀水力填築砂土穩定狀態線及狀態參數與工程特性之關係作廣泛研究。 研究結果顯示,以水力輸砂儀製作之試體,可滿足一般模擬試體均勻性與可重複性的要求。不同孔隙介質對穩定狀態線的影響不大。在本片狀砂土情況下,水力輸砂儀製作之試體,其試驗結果所得之穩定狀態線的斜率與濕搗法製作試體之結果相近似,惟在相同孔隙比下前者之壓縮剪力強度略高於後者;且在同樣水力輸砂試體下,由伸張試驗所得之穩定狀態線顯示其穩定狀態剪力強度較壓縮試驗結果為低。此係受試體組構與應力方向關係所影響。砂土中細料含量增加,穩定狀態線斜率變陡,強度則隨細料的增加而降低。利用狀態參數作為評估片狀水力填築砂土工程特性,可在不同砂土種類及狀態下,獲得其關係曲線相當程度之一致性。
- 英文摘要: Many large scale offshore reclamation projects are now in the planning stage in Taiwan. Mostof these projects will involve the use of hydraulic fill techniques. The need for research related to landreclamation technology has become more obvious in Taiwan, especially for reclamation engineering nearthe seashore using dredging and hydraulic fill techniques. In this research, a sand-water mixture transportation device has been developed to prepare testingsamples. The behavior of the deposition process is evaluated in detail, and a steady state line series andthe correlation between the state parameter and mechanical properties of hydraulic fill sand are investigated.It is observed that the salinity of the pore fluid has no effect on the steady state line. In triaxial andaxial compressive shearing tests, the steady state line obtained from wet tamping specimens showed lowerstrength than did that of specimens created by hydraulic transportation. The axial extension test had lowerstrength than did the axial compression test. This difference was due to the influence of fabric orientationwith respect to principal stress direction. The correlation curves between engineering properties and stateparameters obtained from different sands under different states appear to exhibit a similar trend.
- 中文關鍵字: hydraulic fill; flat shaped sand; mechanical properties; fabric; land reclamation; offshore engineering; state parameter
- 英文關鍵字: --