基于随机场理论的吹填土土性参数空间变异性

根据围海造陆工程吹填场地大量勘察资料,通过采用土层剖面随机场理论与曲线极限法相关距离计算方法,考虑相关距离与土层厚度对土性参数空间变异性的影响,把土性参数的点变异性与空间变异性联系起来,对吹填淤泥与原状淤泥组成的双层软土土性参数的变异性进行了分析。结果表明:吹填淤泥与原状淤泥相关距离的区间估计分别为0.45～0.53 m、0.65～0.71 m,为勘察工作钻孔取样竖向间距选取提供参考;随机场理论计算出的土性参数的空间变异系数比点变异系数小得多,在理论上更合理;吹填淤泥土性参数的点变异性、空间变异性均比原状淤泥大,空间变异性对岩土工程可靠性设计土性参数准确选取的影响更为显著,实际工程中更应考虑土性参数的空间变异性。

Spatial Variability of Property Parameters of Dredged Fill Based on Random Field Theory

Based on the engineering geologic investigation reports of the reclaimed land by dredged fill, the influence of correlation distance and soil thickness on spatial variability of soil property parameters is considered, and the point variability and spatial variability of soil property parameters are associated by means of random field theory of soil profile and curve ultimate calculation method for correlation distance. Then the variability of dredged fill and original silt property parameters are analyzed, the results show that the interval estimation of correlation distance of dredged fill and original silt is separately 0.45-0.53 m and 0.65-0.71 m, which can provide a reference for vertical space in sample boring; the spatial coefficient of variation based on random field theory is much smaller than the point coefficient of variation, which is more reasonable in theory; point coefficient of variation and spatial coefficient of variation of dredged fill is larger than that of original silt, which has a significant influence on accurate selection of soil property parameters in the reliability design of geotechnical engineering, and spatial variability of soil property parameters should be considered in actual projects.