近海粘土设计参数与指标特性之间的关系分析

Correlations between design parameters and index properties for offshore clays

展示了近海粘土指标特性与设计参数之间相关关系的研究结果。该项研究的一个重要目的是建立一个按统一方法测定的高质量的土性测试指标数据库。该数据库由10个场地组成,包括大西洋、挪威北海、挪威海、里海和2个沿海陆上地点。数据库分析表明,前期固结压力pc与液限指数IL之间存在良好的相关关系,但当液限指数小于0.5时,数据比较分散。同时还发现,前期固结压力与由三轴压缩、三轴拉伸及直剪试验测定的不排水抗剪强度之间均有很好的线性相关关系。由此,以pc与IL之间的关系为基础,提出了使用这些线性关系式估算近海粘土原位不排水强度su的方法及建议。

The results of a pilot study investigating correlations between index tests and soil design parameters for offshore clays are presented. An important objective of the study is to develop a database consisting of high quality laboratory data from tests conducted in a consistent manner. The database includes ten sites from locations in the Atlantic Ocean, the North Sea, the Norwegian Sea, the Caspian Sea and two onshore sites. Analysis of the database shows that there exists a better correlation between preconsolidation stress and liquidity index but with considerable scatter as the liquidity index decrease below 0.5. A strong linear relationships between preconsolidation stress and undrained shear strength for triaxial compression, triaxial extension, and direct simple shear test are also found. Recommendations are given for use of these relationships together with the preconsolidation stress-liquidity index correlation for estimation of in situ undrained shear strength.