It has been long recognised that some of the fundamental and engineering properties of soils exhibit a certain degree of anisotropy that eventually dictates their directional geoengineering behaviours. Consideration of the importance of the volume change behaviour of soils during shrinkage and a critical review of the literature suggests scopes for further research for the development of a better understanding of the anisotropy in volume change encountered during soil shrinkage. In this paper, anisotropy in volumetric shrinkage behaviour of soil is depicted with the theory of geometry factor and shrinkage strains. A systematic investigation and analysis on the evolution of geometry factors and shrinkage strains of several geomaterial samples during evaporative dewatering is reported herein. A theoretical framework for evaluating shrinkage geometry factors of a cylindrical soil specimen undergoing volume change during progressive moisture loss is described in this paper. Furthermore, based on experimental and literature data, shrinkage geometry factors of several specimens differing in terms of gradational properties, specimen size, evaporative boundary condition and pore fluid salinity are evaluated and discussed in detail in accordance with the theoretical framework. Linkages between shrinkage process, shrinkages strains and geometry factor are also analysed to underpin the usage of geometry factor and shrinkage strains to characterise anisotropy during soil shrinkage.

长期以来人们一直认识到，土壤的某些基本特性和工程特性表现出一定程度的各向异性，最终决定了土壤的定向地球工程行为。考虑到土壤在收缩过程中体积变化行为的重要性，并对文献进行严格的审查，为进一步了解土壤收缩过程中体积变化的各向异性提供了进一步研究的空间。本文利用几何因子和收缩应变理论描述了土壤体积收缩行为的各向异性。本文报道了在蒸发脱水过程中几种土工材料样品的几何因子和收缩应变的演变的系统研究和分析。本文描述了评估圆柱状土壤试样在渐进的水分流失过程中经历体积变化的收缩几何因子的理论框架。此外，根据实验和文献数据，根据理论框架对几种试样的收缩几何因子进行了评估，并讨论了其分级特性，试样尺寸，蒸发边界条件和孔隙流体盐度方面的差异。还分析了收缩过程，收缩应变和几何因子之间的联系，以支持使用几何因子和收缩应变来表征土壤收缩过程中的各向异性。根据实验和文献数据，根据理论框架，对几种试样的收缩几何因子进行了评估，并讨论了其梯度性质，试样尺寸，蒸发边界条件和孔隙流体盐度方面的差异。还分析了收缩过程，收缩应变和几何因子之间的联系，以支持使用几何因子和收缩应变来表征土壤收缩过程中的各向异性。根据实验和文献数据，根据理论框架，对几种试样的收缩几何因子进行了评估，并讨论了其梯度性质，试样尺寸，蒸发边界条件和孔隙流体盐度方面的差异。还分析了收缩过程，收缩应变和几何因子之间的联系，以支持使用几何因子和收缩应变来表征土壤收缩过程中的各向异性。