海洋环境下人工胶结土长期动力特性研究

Effects of Sea Water Corrosion on Long Term Dynamic Behavior of Cemented Sand

近年来,随着我国对海洋领土的开发,如人工造岛计划的实施,加强了对海洋资源的利用。然而海洋恶劣的气候环境、海水对岛上结构基础地基的腐蚀,对近海结构的耐久性提出了严峻的挑战。本文重点关注利用胶结材料—水泥对砂性地基处理后,地基在海水条件下动力特性的演化,将利用动三轴和共振柱试验获得全应变范围内不同侵蚀时间对人工胶结土的动剪切模量和阻尼比的影响,并对不同浸泡时间的动剪切模量给了拟合公式,同时,给出了预测水泥胶结土长期动剪切模量演化的经验公式,为工程设计提供参考。

Recently,with the development of the offshore structure,such as man-made island,the durability of the superstructure＇s foundation is becoming a challenge to ocean economy. The aim of this investigation is to assess the dynamic behavior of cemented sand under the ocean environment in the long term,including the evolution of dynamic shear modulus and damping ratio. Resonant column and cyclic triaxial test are employed to show the evolution of these parameters in the wide range of strain in terms of soaking period（ SP）,confining pressure（ CP） and cement content（ CC）. The results show that the dynamic shear modulus is significantly improved by the addition of cement,while the damping ratio is not significantly influenced. Finally,a newly empirical relationship for the evolution of shear modulus over soaking periods is proposed.