锁阳城土遗址孔隙结构及其分形特征研究  

Research on the pore structure and fractal characteristics of the Suoyang earthen site

作　　者：张虎元[1,2] 易泉 刘洪丽[3] 李小雅 于洪亮 ZHANG Huyuan;YI Quan;LIU Hongli;LI Xiaoya;YU Hongliang(Key Laboratory of Mechanics on Disaster and Environment in Western China(Lanzhou University),Ministry of Education,Lanzhou 730000,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage(Dunhuang Academy),Jiuquan 736200,China)

机构地区：[1]西部灾害与环境力学教育部重点实验室(兰州大学),甘肃兰州730000 [2]兰州大学土木工程与力学学院,甘肃兰州730000 [3]甘肃省敦煌文物保护研究中心(敦煌研究院),甘肃酒泉736200

出　　处：《文物保护与考古科学》2024年第4期19-31,共13页Sciences of Conservation and Archaeology

基　　金：科技部国家重点研发计划重点专项(2020YFC1522200)资助;甘肃省文物保护科学和技术研究课题(GWJ202020)资助。

摘　　要：在风化因子的持续作用下,土遗址微观结构持续劣化并最终导致宏观病害的发育。微观结构的特征反映了土遗址材料内在的劣化程度,为研究土遗址风化程度与微观孔隙结构变化的关系,采取锁阳城土遗址不同方位城墙土样,采用低温液氮吸附试验测定了土样的比表面积和孔容孔径分布,并基于FHH分形模型计算样品的分形维数;结果表明,锁阳城土遗址不同样品比表面积偏差率高,比表面积数值和分布具有明显差异;孔隙容积变异系数高,离散程度大,存在差异性劣化行为;土样的孔隙形态呈狭缝状、楔形、“墨水瓶”孔、管状孔等多种复杂形态,小于2.765 nm的孔隙大都为封闭透气孔。结合分形维数可知,锁阳城土样具有明显的分形特征,孔隙空间结构不规则,非均质性强,表面粗糙程度大,且分形维数和锁阳城土遗址劣化程度具有一定相关性。本研究关于土样孔隙的定量表征对于土遗址风化劣化研究有着重要意义。Under the persistent action of weathering factors,the microstructure of earthen sites continues to deteriorate,leading eventually to the development of macro diseases.The variation of microstructural characteristics reflects the inherent weathering degree of soil materials.In order to study the correlation between deterioration and the micro-pore structure of the Suoyang earthen site,a low temperature-liquid nitrogen adsorption test was conducted on soil specimens sampled from the city wall in different directions at the site for the determination of specific surface area,pore volume and pore size distribution characteristics,and the fractal dimension of the specimens was calculated based on the FHH fractal model.The research data show that Suoyang soils demonstrated a high deviation rate in specific surface area,and obvious difference in specific surface area of the specimens in different directions.The soils were mainly the micropores with a high coefficient of variation in pore volume and large dispersion degree,corresponding to weathering difference between them.The pore morphology included slit,wedge,“ink bottle”,tubular hole,and other complex forms.The pores less than 2.765 nm were mostly closed pores.In combination with the fractal dimension,it is found the soil specimens featured obvious fractal characteristics,irregular pore space structure,strong heterogeneity and large surface roughness.The fractal dimension had a certain correlation with the weathering or deterioration degree.The quantitative characterization of soil pores is of importance for the evaluation of weathering and deterioration of earthen sites.

关 键 词：锁阳城土遗址 低温氮吸附试验 分形维数 孔隙结构特征 风化 

分 类 号：K876.6[历史地理—考古学及博物馆学]