降雪、温差作用下大尺寸砂岩风化模拟试验研究  

Simulation experiment study on large-size sandstone weathering under coupling effect of snow and temperature

作　　者：刘晓颖 郭青林[1,2,4] 张博 尚东娟[1,2,3,4] 余静 裴强强 LIU Xiaoying;GUO Qinglin;ZHANG Bo;SHANG Dongjuan;YU Jing;PEI Qiangqiang(Dunhuang Academy,Dunhuang,Gansu 736200,China;National Research Center for Conservation of Ancient Wall Paintings and Earthen Sites,Dunhuang,Gansu 736200,China;Gansu Mogao Grottoes Cultural Heritage Conservation Design and Consultation Co.,Ltd.,Dunhuang,Gansu 736200,China;Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage,Dunhuang,Gansu 736200,China)

机构地区：[1]敦煌研究院,甘肃敦煌736200 [2]国家古代壁画与土遗址保护工程技术研究中心,甘肃敦煌736200 [3]甘肃莫高窟文化遗产保护设计咨询有限公司,甘肃敦煌736200 [4]甘肃省敦煌文物保护研究中心,甘肃敦煌736200

出　　处：《岩石力学与工程学报》2024年第6期1519-1534,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U22A20599);敦煌研究院院级科研课题(2022-KJ-YB-5)。

摘　　要：砂岩质石窟寺在冻融循环作用下,会引起不同程度的风化病害。以甘肃北石窟寺为研究对象,以所处赋存环境的多因素变量耦合关系为依据,在多场耦合实验室开展降雪-温差条件下的大尺寸砂岩风化模拟试验。结果表明,反复的降雪-温差作用下,在微观上,冻胀消融使得砂岩表现出表层砂岩胶结物几乎全部消失,内部砂岩胶结方式以接触式为主以及孔隙增多增大的劣化特征;宏观上,呈现出水分入渗深度增大、损伤区域及损伤程度逐步扩展,并伴随着起翘脱落、变色加深、裂隙发育的表观现象,力学上,表现为强度逐渐降低的趋势,并根据不同岩性砂岩划分出5类响应敏感区域,揭示了降雪-温差作用下砂岩的渐进累计风化机制。Sandstone grotto temples are subject to varying degrees of weathering damage when exposed to freezethaw cycles.This study focuses on the North Grottoes in Gansu,employing a multi-faceted approach based on the coupled relationships of numerous environmental factors.Large-scale sandstone weathering simulations were conducted in a sophisticated multi-field coupling laboratory under conditions emulating snowfall-temperature variations.The findings reveal that repetitive snowfall-temperature fluctuations induce freeze-thaw cycles,causing significant microstructural changes in the sandstone.At the microscopic level,freeze-thaw cycles result in the nearly complete dissolution of surface sandstone cementation.Internally,the sandstone exhibits a degradation characterized by a predominant contact-type cementation breakdown,accompanied by a noticeable increase in pore volume and size.Macroscopically,there is a discernible augmentation in the depth of moisture infiltration,coinciding with a progressive expansion of damaged regions and an intensification in the severity of observed deterioration.Surface manifestations include warping,detachment,deepening discoloration,and widening of cracks.Mechanically,there is a gradual decline in strength.Moreover,a categorization of five distinct response-sensitive zones was established based on different sandstone rock types.This classification sheds light on the progressive cumulative weathering mechanism of sandstone under the influence of snowfall-temperature fluctuations.

关 键 词：岩石力学 砂岩 石窟寺 冻融循环 降雪-温差 多因素变量耦合 风化机制 

分 类 号：TU45[建筑科学—岩土工程]