英文篇名
THE DAMAGE TYPES AND POTENTIAL EVALUATION OF SOIL LIQUEFACTION
作者
鄭文隆、吳偉康
摘要
土壤液化為土壤的破壞型式之一,意指土壤由彈塑行為轉變為液性行為。在古老的文獻中不乏對土壤液化的記載,但大都僅止於一種現象描述而已,真正對土壤液化(Soil Liquefaction)進行分析者可能要溯源自Hazen(1920)及Casagrande(1976)之研究,該兩分析係分別針對1920年及1938年左右美國加州Calaveras埧及蒙他納州Fort Peck埧破壞情形所作的研究,惟在那個時代土壤力學正值啟蒙期,土壤動力學尚未明顯建立,故有關液化的研究侷限於靜力破壞方面即土壤在單一方向荷重(Monotonic Loading)下造成之液狀化破壞,此與目前普遍化的液化問題研究在方向上不太相同。
目前之液化研究係以1964年為里程碑,其研究範疇以動力作用下之土壤破壞為主體。在1964年,日本新瀉地區(Niigata)及美國阿拉斯加地區(Alaska)分別發生了地震規模7.5及8.3的強震,造成了新瀉地區極戲劇性的液化破壞及阿拉斯加地區大規模的山崩,這二個強烈大地震在一年間震撼了整個工程界,更引發了二十年來土壤動力學領域裡最熱絡之一的液化研究。本文中有關液化之破壞及現地研制等敘述亦將針對地震引致之動力荷重加以檢討與分析。
英文摘要
In 1964, the famous Niigata earthquake and Alaska earthquake occurred and caused very huge disaster in both Niigata and Alaska area. Through the study of post-earthquake investigation, the damages caused by those two earthquakes were attributed mostly to the result of soil liquefaction. Since that time, the study of soil liquefaction has been very active in the field of soil dynamics.
Many researches and achievements have been done in the last twenty years, and people nowadays have already recognized the importance of liquefaction problem in dealing with an earthquake engineering design. Therefore, in this paper, the damage types of site and structures are summarried and described. Also, the evaluation of liquefaction potential of the Site by using the results of standard penetration test and cone penetration test are introduced as a reference for practice engineers when doing field judgements.