西北干旱区遗址夯土时空性特征研究

Temporal and spatial characteristics of rammed earth in arid area of Northwest China

夯土的时代与地域属性是决定西北干旱区的历代夯土遗址是否具有差异性病害类型和发育程度表现的本质原因,缺乏对其精准认识与量化表征严重制约了夯土遗址的科学保护.研究选择分布于3个气候区域、5个朝代的15处遗址夯土为研究对象,通过基本物理性质测试、无侧限抗压强度试验、SEM扫描电镜试验与结构性理论分析,从定性与定量两个方面展开了对夯土时空性特征的研究.研究结果表明:15处遗址夯土具有建造时代越久远、所处区域越干燥,其塑性和液性指数越小、抗压强度越高的显著性时空特征,其微观结构致密程度、孔隙类型、数量、大小以及联通情况与上述宏观性质特征具有良好的一致性表述,其干构度与建造距今年限和干旱指数均存在显著的线性对应关系.

The era and regional attributes of rammed earth are the essential reasons for the different disease types and development degree of rammed earth sites in the arid areas of Northwest China.However,the lack of accurate understanding and quantitative characterization of thosehave become the core basic problem that seriously restricts the scientific protection of rammed earth ruins.In this study,15 ruins of rammed earth distributed in 3 climatic regions and 5 dynasties were selected as the research objects.Through basic physical properties test,unconfined compressive strength test,SEM test and structural theoretical analysis,the temporal and spatial characteristics of rammed earth were studied from both qualitative and quantitative aspects.The results show that the rammed earth of the 15 ruins have obviously temporal and spatial characteristics,which is the older the construction era in,the drier the region at,the smaller it's plasticity and liquidity index and the higher compressive strength.The density degree of microstructure,type,number,size,and connectivity of pores are well consistent with the above macroscopic property characteristics.There is anobvious linear correlation between the dry structure index and the age of construction and the drought index.