細粒料含量對麥寮砂動態行為之影響

Abstract

在過去四十年間，室內試驗關於乾淨砂不排水應力應變行為與抗液化強度，已經有相當好的結果。然而，在自然界中，許多的天然砂土中都具有細粒料，根據現地液化後的觀察結果，含細粒料的砂土其液化行為與乾淨砂有明顯之差異。本研究所使用的麥寮砂（MLS）為台灣西部地區典型砂土，具有相當高含量的粉土（silt）。根據過去試驗結果顯示，麥寮砂具有高壓縮性且膨脹性不高之特性。 本研究目的主要以不同細粒料含量之麥寮砂，進行反覆動力三軸試驗，並於三軸試驗設備中加入剪力波元件（bender element），以求得其抗液化強度與剪力波速，配合現有圓錐貫入試驗結果，界定出麥寮砂之土壤液化邊界曲線。本論文中敘述研究之背景、目的、試驗程序與試驗結果資料，並對於粉土細砂中抗液化強度與剪力波速結果進行分析、討論並提供建議。

During the past 40 years, extensive laboratory studies on undrained stress-strain behavior and liquefaction resistance of clean sands have been performed. Natural sands often contain various amounts of fines and are expected to have different behavior. This research concentrated on Mai Liao Sand(MLS), which is a typical silty sand found in Central Western Taiwan. MLS is relatively compressible and has less tendency to dilate when sheared. A series of cyclic triaxial tests have been performed on MLS with different fines content in this research. A triaxial cell equipped with bender elements was used to measure cyclic strength and shear wave velocities of the specimen. The thesis describes the background of the research, objectives, and it’s approach. The test results were analyzed and the influence of fines contents on MLS were discussed.