莫高窟壁画地仗土的土水特性研究  

The Soil-Water Characteristics of Base Coat in Mogao Grottoes Murals

作　　者：赵天宇[1] 张虎元[1] 严耿升[1] 刘平[1] 张永霞[1] 

机构地区：[1]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《敦煌研究》2011年第6期36-42,共7页Dunhuang Research

基　　金：国家科技支撑计划课题(2006BAK30B02);古代壁画保护国家文物局重点科研基地开放课题(200806)

摘　　要：水分运动引起的盐分迁移、富集及土水相互作用引起的土体应力变化已成为壁画病害发生的重要原因,本文通过室内试验开展地仗土的土水特性研究,期望能为壁画病害防治提供理论支持。利用压力膜仪实测莫高窟壁画地仗制作材料——澄板土的土水特征曲线,分析了澄板土基质吸力随含水量的变化趋势,研究了澄板土的土水特征曲线形态及描述模型。利用柔性壁渗透仪实测澄板土的饱和导水率,采用Van Genuchten(1980)预测模型计算得到不同含水量条件下澄板土的非饱和导水率,建立了非饱和导水率与含水量、基质吸力的相关关系,结果表明澄板土的非饱和导水率随含水量减小呈非线性降低,高吸力段(100—100000kPa)在双对数坐标中随基质吸力增加以某一特定速率线性下降。There are two important causes of mural deterioration. One is the salt migration and enrichment caused by water movement, and the other is the soil stress change caused by soil-water interaction. Both are related to the soil-water characteristics. This paper describes the research on the soil-water characteristics of the soil in mural plaster by laboratory tests, intending to provide theoretical guidance for mural conservation. By using pressure plate extractors, the soil-water characteristic curve （SWCC） of washed soil （clengbantu）, which is the plaster material in the Mogao Grottoes murals, was measured. The relationship between matrix suction and water content was analyzed, and the curve morphology and model for SWCC of washed soil were also studied. The saturated hydraulic conductivity of washed soil was tested by flexible-wall permeameter, and then the unsaturated hydraulic conductivity in different water content was calculated through the Van Genuchten （1980） prediction model. Based on the measurement and calculation, the correlation between unsaturated hydraulic conductivity and water content （matrix suction） was established. Research results show that the unsaturated hydraulic conductivity of washed soil decreases non-linearly as the water content decreases, while at a high-suction section （100-100000kPa） it has a linear decline at a certain specific rate as the matrix suction increases in double logarithmic coordinates.

关 键 词：澄板土 含水量 土水特征曲线 非饱和导水率 

分 类 号：K879.4[历史地理—考古学及博物馆学] P642.1[历史地理—历史学]