台湾西部外海回填土壤剪切模量与阻尼比之研究(英文)

A study on the shear modulus and damping ratio of reclaimed soil in Yun Lin nearshore area

本研究采用云林外海的土壤进行共振柱试验，以求得回填土壤之剪切模量与阻尼比。试验资料正规化（Ｇ／Ｇｍａｘ）与剪应变振幅（γ）关系曲线位于Ｓｅｅｄ和Ｉｄｒｉｓ所建议曲线的上限范围，而阻尼比与剪应变振幅关系曲线则位于其下限范围。采用Ｓｅｄ和Ｉｄｒｉｓ评估土壤剪力数模的方式，建立不同细粒含量回填土壤于不同相对密度下，所对应的Ｋ２值之相关图表，以提供作为回填造地工程规划之参考。同时本研究利用静力三轴试验结果，以弹性理论推求于轴应变为１％时所对应之偏应力与最大剪切模量具有相关联性。利用本研究所建立之回填土壤动态特性相关评估方式及图表可作为回填土壤造地时有关承受动态荷重基础及结构物之参考。

In this study, using the filled material in Yun Lin nearshore area as test samples, a series of resonant column test has been performed to evaluate the dynamic properties of filled material. From the test results, the relation curve of normalized shear modulus (G/G max ) vs. shear strain ( γ ) lies on the upper bound of the curve suggested by Seed and Idriss, and the damping ratio ( D ) vs. shear strain ( γ ) lies on the lower bound of the suggested curve. The influence of confining pressure, different fines contents and relative densities on dynamic properties of reclaimed soil were discussed. Based on the equations suggested by Seed and Idriss, a new proposed method was established to evaluate the shear modulus of reclaimed soil under different fine contents and relative densities. Using the resonant column triaxial test and static triaxial test results, and based on elastic theory for 1% of axial strain, the deviator stress and G max are found to be related. The results shown in this paper can be used as a reference for foundation and structure design in land reclamation area.