中文摘要：

土体空间变异性分析是进行岩土工程可靠度设计的理论基础。采用随机场理论,提出了典型江苏海相黏土的随机场特征及参数,对基于孔压静力触探（CPTU）测试数据的空间变异性进行了系统分析。由于竖直方向上CPTU锥尖阻力数据的样本容量较高,通过对锥尖阻力进行一次多项式去趋势来获得平稳的波动分量,并利用常用的5种自相关模型拟合波动分量的自相关系数。采用修正的Bartlett统计公式来检验波动分量的平稳性,选取最优的竖直波动范围。竖直变异系数由波动分量和去趋势函数来确定。鉴于水平方向上的CPTU锥尖阻力数据的样本容量较小,采用平均零跨距法估计水平波动范围,水平变异系数由总体变异系数来表示。结果表明,竖直向和水平向上江苏海相黏土较报道值显示出更强的空间变异性。

英文摘要：

Analysis of soil spatial variability is the basis for the reliability study of geotechnical engineering. Based on the CPTU data, the random field model parameters of Jiangsu marine clay are determined employing the random field theory, and the spatial variability is also discussed. Given the relatively high sampling frequency of the cone tip resistance in the vertical direction, the cone tip resistance data is processed by the linear trend removal method to get fluctuation components. The coefficient of autocorrelation is estimated by using five autocorrelation models, and the stationarity of fluctuation components is verified by the modified Bartlett’s statistics. The optimum vertical scale of fluctuation is selected from the five verified autocorrelation functions. The vertical coefficient of variation is assessed by the fluctuation components and trend removal functions. In light of lack of CPTU data in the horizontal direction, the horizontal scale of fluctuation is generated using the Vanmarcke’s expeditive method. The horizontal coefficient of variation is expressed as the total coefficient of variation. The study shows that Jiangsu marine clay exhibits greater variability than the clay previously reported in other sites in both the vertical and horizontal directions.