本研究使用兩種試驗方法，一為Stokoe固定–自由型式(fixed-free)共振柱試驗，另一為自由-自由型共振頻率法(free-free resonant frequency method)，試驗岩心為變質砂岩，取樣自台灣東北部地區，在共振柱試驗中改變不同試體尺寸、黏著劑成份、驅動系統質量慣性矩、有效圍壓進行試驗，觀察控制參數與兩種試驗方法對硬岩之剪力模數與阻尼比之影響。
研究結果顯示，在共振柱試驗中，求取硬岩之剪力模數將會被低估而需要修正，且誤差隨量測試體之共振頻率越高而越大，然而修正結果顯示修正程序能有效減少誤差。
在共振柱試驗之控制參數方面，黏著劑成份使用氰基丙烯酸酯能使試體與驅動系統之耦合性更佳；有效圍壓對於硬岩之動態特性並無明顯影響；隨試體尺寸越小，量測之共振頻率變小，剪力波速變大且阻尼比有越小的趨勢，而剪力模數及阻尼比之門檻剪應變皆有提高的趨勢；隨驅動系統質量慣性矩越大，量測試體之共振頻率變大，剪力波速變大，其中以頂蓋及驅動盤皆為鋁材質所量測試體之阻尼比較小，然而頂蓋及驅動盤皆為不鏽鋼材質所量測試體之阻尼比較大。
以兩種試驗方法之量測結果顯示，以自由-自由型共振頻率法推求試體之阻尼比較固定-自由型共振柱試驗小，剪力模數則較大。

關鍵字：共振柱試驗、岩石、剪力模數、阻尼比、動態特性。

In this research, the Stokoe-type fixed-free resonant column test and free-free resonant frequency method were exploited to obtain the dynamic properties of hard rock. The rock samples were metamorphic sandstones which extracted from the northeast of Taiwan. In resonant column test, the specimens with different sizes, ingredients of adhesive, mass moment of inertia of drive system and confining pressure were conducted in high amplitude test, half-power bandwidth method and free vibration decay method to acquire the shear modulus and the damping ratio. In resonant column test, the research results show that (1) the shear modulus of the hard rock will be underestimated and needs to be corrected. The error in the estimation of shear modulus increases with the increasing in the measured resonant frequency. However, the correction results show that the correction procedure is the effective way to reduce error. (2) The use of cyanoacrylate as the adhesive ingredient makes the coupling between the specimen and the drive system better. (3) The confining pressure has no significant effect on the dynamic properties of hard rock. (4) The shear modulus increases with decreasing specimen size and increasing mass moment of inertia of drive system. (5) The damping ratio decreases with decreasing specimen size and decreasing mass moment of inertia of drive system. (6) The threshold shear strain of the shear modulus and damping ratio both increase with decreasing specimen size. (7) The measured frequency of specimen decreases with decreasing specimen size and decreasing mass moment of inertia of drive system. (8) The shear modulus obtained from fixed-free resonant column test is lower than from free-free resonant frequency method. (9) The damping ratio obtained from fixed-free resonant column test is higher than from free-free resonant frequency method.

key words: resonant column test, rock, shear modulus, damping ratio, dynamic properties

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