空间递推平均法在估计土性指标自相关距离中的应用  

APPLICATION OF SPATIAL AVERAGE METHOD TO ESTIMATION OF SCALE OF FLUCTUATION OF SOIL INDEXES

作　　者：郭林坪[1,2] 许文祥[3] 杨爱武[1] 刘晓强 

机构地区：[1]天津城建大学天津市软土特性与工程环境重点实验室,天津300384 [2]中交天津港湾工程研究院有限公司港口岩土工程技术交通行业重点试验室天津市港口岩土工程技术重点试验室,天津300222 [3]天津市建筑设计院,天津300074 [4]交通运输部天津水运工程科学研究院,天津300000

出　　处：《工程地质学报》2017年第6期1424-1429,共6页Journal of Engineering Geology

基　　金：港口岩土工程技术交通行业重点实验室基金(14-50);天津市自然科学基金(15JCQNJC07900;15JCZDJC40600)资助

摘　　要：像许多土层一样,黏性土层的土性参数也具有空间变异性。土性参数的空间变异性主要是由沉积和成岩等地质作用和环境因素导致的,而相关距离的确定是分析土性参数空间变异性的关键。为了分析天津南疆港地区土层参数的空间变异性,对确定土性参数相关距离的空间递推平均法及其改进方法进行了汇总分析,并结合地质勘查资料,运用改进的空间递推平均法对天津港地区典型土层的垂直相关距离进行了统计分析,得到了典型土层地区性代表值,对该地区岩土工程的可靠度分析及勘探点位的选取具有重要的指导意义。此外,还结合工程实例讨论了相关距离的贝叶斯估值法,贝叶斯估值法比直接取平均值确定自相关距离的方法更为可靠、合理,应用贝叶斯定理对天津港南疆石化码头淤泥及淤泥质黏土层的自相关距离进行估值,为今后该地区的取样间距选择提供参考,也为可靠度理论在该地区岩土工程中的应用提供有价值的参数。Like most other soil layers, spatial variability of soil indexes also exists in the clayey layers. Such characteristic mainly results from geologic processes like deposition, diagenesis, et al. Determination of the scale of fluctuation is the key to know spatial variability of soil indexes. Therefore, this paper aims to analyze spatial variability of indexes of clayey soil in Nanjiang Port in Tianjin. It summarizes the spatial average method and its improved method at first. Combining geology data, the improved spatial average method is employed to analyze thescale of fluctuation of a typical soil layer in Tianjin Port in the vertical direction. The regional representative values are obtained, which are of high value on risk assessment in geotechnical engineering and determination of exploratory engineering intervals. In addition, the Bayesian inference is also discussed to revise the scale of fluctuation. Its results indicate that the Bayesian inference is much more reasonable. Furthermore, the scale of fluctuation of the mud and silt clay layer can be guidance for selection of sampling locations, and also valuable to reliability analysis of geotechnical engineering.

关 键 词：空间变异性 自相关距离 空间递推平均法 贝叶斯原理 

分 类 号：TU441[建筑科学—岩土工程]