云冈石窟顶部土层水盐分布特征研究

可溶盐是石质文物风化的重要原因,其聚集、运移与水密不可分。石窟顶部土层中的盐是云冈石质文物内部盐分的重要来源,因而研究石窟顶部土层中的水盐分布特征对未来减小可溶盐在石质文物内部的聚集具有十分重要的意义。本研究对云冈石窟顶部不同位置、不同深度土层的饱和渗透系数、含水率、孔隙比、可溶盐含量进行了系统的分析测试,并结合取土位置的坡度和植被覆盖率,研究了云冈石窟顶部土层中水盐分布特征。结果表明:植被覆盖率越高,土体含水量越高;坡度越大,土体含水率越低;土体孔隙比与饱和渗透系数呈线性关系。植被覆盖率、坡度及土体的渗透性能是影响石窟顶部土层水盐分布的主要原因。

Study of water and salt distribution characteristics in the top soil layer of Yungang Grottoes

Soluble salts are an important cause of the weathering of stone relics. Accumulation and migration of soluble salts is inseparable from water. Salts in the top soil layer of Yungang Grottoes are an important source of the interior salts of Yungang stone relics. Therefore, it is of great significance to study the distribution characteristics of water and salts in the top soil layer of grottoes for the goal of reducing the accumulation of soluble salts in stone relics in the future. In our work, the saturated permeability coefficient, water content, void ratio and soluble salt content of soils at different depths and different locations in the top of Yungang Grottoes were systematically analyzed and tested. The distribution characteristics of water and salts in the top soil layer of Yungang Grottoes were studied in combination with the slope and vegetation coverage ratio at the sampling locations. The results show that 1) the higher the vegetation coverage ratio, the higher the water content of soil samples; 2) the larger the slope, the lower the water content of soil samples and 3) the void ratio and the saturated permeability coefficient show a linear relationship. The vegetation coverage ratio, slope and permeability are the main factors affecting the distribution of water and salts in the top soil layer of grottoes.