砂土液化後之不排水殘餘強度為進行液化土層之穩定性分析與設計時之重要參數，本研究採用不同相對密度之渥太華砂與不同細粒料含量之麥寮砂試驗，以K0中空扭剪系統，在相同壓密應力下，先將試體以動態之正弦波反覆剪應力進行剪動，當試體之超額孔隙水壓比達到1.0時視為液化，接著以剪動速率2%/min進行靜態之單向剪動，求取不同相對密度下之液化後不排水殘餘強度。研究結果顯示，在單向剪動前期，隨著剪應變越大，超額孔隙水壓比會持續維持在1.0且初始剪力模數遠小於液化前初始剪力模數；然而在單向剪動之中後期，超額孔隙水壓比會隨著剪應變增大而減少，且剪力阻抗增加，故定義當超額孔隙水壓比開始下降時之剪應變所對應之剪應力為液化後之殘餘強度。實驗結果顯示，液化後之殘餘強度，在不同的初始相對密度下會趨近相同且殘餘強度會隨著細粒料含量的上升而下降。

Post liquefaction residual strength of sand is an important parameter for the stability analysis and design of the liquefied soil layer. In this study, a K0 hollow cylinder apparatus was used to measure the post liquefaction residual strength of sandy soil. Clean Ottawa sand specimens with different relative densities after consolidated and Mai-Liao sand (MLS) specimens with different fine contents were tested. The water pluviation technique was used to prepare remolded specimens under the same effective consolidated stress. All specimens were sheared using sinusodial shear stress to excited the excess pore water pressure ratio to reaches 1.0 and this state is defined as the initial liquefaction. Following the initial liquefaction, the specimens were then monotonically sheared at a constant strain rate of 2%/min to investigate the post liquefaction residual strength of sandy soil. The results show that in the beginning of monotonic shearing, the excess pore water pressure ratio maintained at 1.0. In the following stages of the monotonic shearing, the excess pore water pressure ratio decreased with increasing shear strain. Therefore, this study defines the shear stress corresponding to the shear strain where the excess pore water pressure ratio begins to be less than 1.0 as the post liquefaction residual strength. The results show that the post liquefaction residual strength is independent of initial relative densitieswith a residual strength ratio of 0.21. Furthermore, the residual strength ratio of MLS will decrease from 0.26 to 0.21 as the fines content increase from 0 to 35%.

張嘉偉 (1997) 圓錐貫入試驗在粉砂中之標定，國立交通大學土木工程學系，碩士論文。
陳昱愷 (2018) 應用中空扭剪試驗探討剪應變速率對土壤動態特性之影響，國立成功大學土木工程學系，碩士論文。
龍麒安 (2019) 以中空扭剪探討近斷層加載下砂土液化行為，國立成功大學土木工程學系，碩士論文。
Ampadu, S., & Tatsuoka, F. (1993). A Hollow Cylinder Torsional Simple Shear Apparatus Capable of a Wide Range of Shear Strain Measurement. Geotechnical Testing Journal, 16(1), 3-17.
Chang, W.-J., Chang, C.-W., & Zeng, J.-K. (2014). Liquefaction Characteristics of Gap-graded Gravelly Soils in K0 Condition. Soil Dynamics and Earthquake Engineering, 56, 74-85.
Hight, D. W., Gens, A., & Symes, M. J. (1983). The development of a new hollow cylinder apparatus for investigating the effects of principal stress rotation in soils. Géotechnique, 33(4), 355-383.
Idriss, I. M., & Boulanger, R. W. (2007). SPT- and CPT-Based Relationships for The Residual Shear Strength of Liquefied Soils., Earthquake Geotechnical Engineering: 4th International Conference on Earthquake Geotechnical Engineering-Invited Lectures, 1-22.
Ishihara, K., & Li, S.-i. (1972). Liquefaction of Saturated Sand in Triaxial Torsion Shear Test. Soils and Foundations, 12(2), 19-39.
Iwasaki, T., Tatsuoka, F., & Takagi, Y. (1978). Shear Moduli of Sands under Cyclic Torsional Shear Loading. Soils and Foundations, 18(1), 39-56
Iwasaki, T., Arakawa, T., & Tokida, K.-I. (1984). Simplified procedures for assessing soil liquefaction during earthquakes. International Journal of Soil Dynamics and Earthquake Engineering, 3(1), 49-58.
Kokusho, T., Hara, T., & Hiraoka, R. (2004). Undrained Shear Strength of Granular Soils with Different Particle Gradations. Journal of Geotechnical and Geoenvironmental Engineering, 130(6), 621-629.
Naeini, S. A., & Baziar, M. H. (2004). Effect of fines content on steady-state strength of mixed and layered samples of a sand. Soil Dynamics and Earthquake Engineering, 24(3), 181-187.
Poulos, S., Castro, G., & France, J. (1985). Liquefaction Evaluation Procedure. Journal of Geotechnical Engineering, 111, 772-792.
Saada, A. S. (1988). State-of-the-Art Paper: Hollow Cylinder Torsional Devices: Their Advantages and Limitations. R. T. Donaghe, R. C. Chaney, & M. L. Silver (Eds.), 766-789. West Conshohocken, ASTM International.
Seed, H. B. (1979). Considerations in the earthquake-resistant design of earth and rockfill dams. Géotechnique, 29(3), 215-263.
Seed, H. B., Martin, P. P., & Lysmer, J. (1975). The Generation and Dissipation of Pore Water Pressures During Soil Liquefaction: College of Engineering, University of California.
Sivathayalan, S., & Yazdi, A. (2004). Post liquefaction response of initially strain softening sand. 215-221.
Tatsuoka, F., Sonoda, S., Hara, K., Fukushima, S., & Pradhan, T. B. S. (1986). Failure and Deformation of Sand in Torsional Shear. Soils and Foundations, 26(4), 79-97.
Vaid, Y., Sivathayalan, S., & Stedman, D. (1999). Influence of Specimen-Reconstituting Method on the Undrained Response of Sand. Geotechnical Testing Journal, 22(3), 187-195.
Vaid, Y. P., & Sivathayalan, S. (1996). Static and cyclic liquefaction potential of Fraser Delta sand in simple shear and triaxial tests. Canadian Geotechnical Journal, 33(2), 281-289.
Yasuda, S., Yoshida, N., Adachi, K., Kiku, H., Gose, S., & Masuda, T. (1999). A Simplified Practical Method for Evaluating Liquefaction-Induced Flow. Doboku Gakkai Ronbunshu, 638, 71-89.