本研究利用共振柱試驗儀對渥太華標準砂(C-109)、台北捷運北投機場粉土質土壤、雲林麥寮水力回填砂、越南峴港砂及台中火力發電廠之水力回填煤灰進行共振柱排水試驗，探討平均有效圍壓、相對密度(孔隙比)及剪應變振幅對上述土壤動態性質之影響，建立各土壤之最大剪力模數與孔隙比、圍壓之經驗關係，以及正規化動態性質曲線。可供地盤受震反應分析中選取土壤動態參數之用。 本研究採用美國GCTS公司製造之Stokoe式固定-自由型共振柱試驗系統進行試驗。首先針對儀器不具飽和土壤之功能及剪應變量測系統之缺陷進行改良，改良後共振柱試驗儀之功能已能符合一般試驗之要求，經標準土樣之對比及重複試驗結果，顯示此部共振儀所測試的土壤動力性質試驗結果，頗為良好。之後，針對不同有效圍壓、相對密度(孔隙比)及剪應變振幅之情況，進行上述各種土壤之動態性質試驗，探討各種土壤之動態性質與其相關影響因素。 研究結果顯示，各種土壤之剪力模數隨著有效圍壓及相對密度增加而有增加的趨勢，但隨著剪應變振幅的增加呈現顯著非線性的減小趨勢；阻尼比隨著有效圍壓之增加而有遞減的趨勢，但隨著剪應變振幅的增加而呈現非線性的增加；相對密度(孔隙比)對阻尼比之影響則不明顯。 The dynamic shear modulus and the damping properties of soil for ground response analysis are influenced by numerous factors. In this research, shear modulus and damping ratio of several soils, including the Ottawa standard sand C-109, Taipei basin silt, YunLin Mai-Liao sand, Vietnam Danang sand and coal ash were investigated by a resonant column apparatus. Reconstituted samples with various initial void ratios were subjected to different mean effective confining pressure and shear strain amplitudes to investigate their effects on the dynamic properties. Stokoe type fixed-free resonant column device was assembled, calibrated and modified so that reconstituted saturated specimens could be tested at various confining pressure and shearing strain amplitude. The results computed from the resonant column tests of standard soil samples and from Hardin and Richart (1963) were in good agreement, confirming that the assembled resonant column system were operating properly. The relationship of maximum shear modulus, effective confining pressure and void ratio was established based on the resonant column test results. And the normalized curves of dynamic properties were also established. These results can be helpful in the seismic ground response analysis. It could be concluded from this study that in certain conditions, shear modulus pronouncedly increases with effective confining pressure and relative density, decreases with shearing strain amplitude. The damping ratio decreases with effective confining pressure and increases with shearing strain amplitude. Effect of void ratio on damping ratio is negligible.
