Deterioration mechanisms of conglomerate under dry-wet and freeze-thaw cycles: A case study of the Yulin Grottoes
ZHANG Huihui1,2, WANG Yanwu2, GUO Qinglin2, WANG Xuezhi2, TANG Chun?an1, TANG Shibin1
(1. School of Civil Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China; 2. Conservation Institute, Dunhuang Academy, Dunhuang, Gansu 736200, China)
Abstract：The Dunhuang Grottoes represent a significant segment of China?s grotto temples; however, the cliff faces are highly vulnerable to weathering due to the wet-dry and freeze-thaw cycles, posing a serious threat to their long-term preservation. To investigate the deterioration mechanisms of the conglomerate rock in the Dunhuang Grottoes under these conditions, this study conducted laboratory tests simulating wet-dry and freeze-thaw cycles on conglomerate samples, utilizing regional environmental monitoring data as a reference. The findings reveal that: (1) Wet-dry and freeze-thaw cycles significantly reduce the mass, P-wave velocity, and uniaxial compressive strength of the conglomerate samples while markedly increasing their permeability; (2) Water plays a critical role in the deterioration process of the conglomerate, particularly during freeze-thaw cycles involving moisture, where the rate of deterioration accelerates and is positively correlated with water content. Compared to the fresh, dry samples, the uniaxial compressive strength decreased by 13% in the wet-dry cycle group, 12% in the dry freeze-thaw group, 36% in the saturated freeze-thaw group, and 25% in the natural freeze-thaw group; (3) Microscopic analysis indicates that the degradation of the conglomerate under wet-dry and freeze-thaw cycles results from significant changes in microstructure, including surface roughening of micro-mineral particles, structural loosening, weakening of cementation, and the formation of microcracks. These results provide crucial theoretical support for the protection of the Dunhuang Grottoes against weathering.
张慧慧1，2，王彦武2，郭青林2，王学智2，唐春安1，唐世斌1. 干湿和冻融循环作用下敦煌石窟砾岩劣化机制试验研究——以榆林窟为例[J]. 岩石力学与工程学报, 2025, 44(S2): 188-199.
ZHANG Huihui1,2, WANG Yanwu2, GUO Qinglin2, WANG Xuezhi2, TANG Chun?an1, TANG Shibin1. Deterioration mechanisms of conglomerate under dry-wet and freeze-thaw cycles: A case study of the Yulin Grottoes. , 2025, 44(S2): 188-199.
[1] AGNEW N，JINSHI F. China?s buddhist treasures at Dunhuang[J]. Scientific American，1997，277(1)：27–40.
[2] 赵晓星. 莫高窟之外的敦煌石窟[M]. 敦煌：敦煌文艺出版社，2017：1–3.(ZHAO Xiaoxing. Dunhuang grottoes other than Mogao Grottoes[M]. Dunhuang：Dunhuang Literary Press，2017：1–3.(in Chinese))
[3] FRIESEN O，DASHTGARD S，MILLER J，et al. Permeability heterogeneity in bioturbated sediments and implications for waterfooding of tight-oil reservoirs，Cardium Formation，Pembina Field，Alberta，Canada[J]. Marine and Petroleum Geology，2017，82：371–387.
[4] KREZSEK C，FILIPESCU S，SILYE L，et al. Miocene facies associations and sedimentary evolution of the Southern Transylvanian Basin (Romania)：Implications for hydrocarbon exploration[J]. Marine and Petroleum Geology，2009，27(1)：191–214.
[5] MAHMIC O，DYPVIK H，HAMMER E. Diagenetic influence on reservoir quality evolution，examples from Triassic conglomerates/ arenites in the Edvard Grieg field，Norwegian North Sea[J]. Marine and Petroleum Geology，2018，93：247–271.
[6] HAO Z G，FEI H C，HAO Q Q，et al. The world’s largest conglomerate type oilfield has been discovered in the Junggar Basin of China[J]. Acta Geologica Sinica，2018，92：394–395.
[7] SHEN T J，LIN B. A novel machine learning framework for efficient calibration of complex DEM model：A case study of a conglomerate sample[J]. Engineering Fracture Mechanics，2023，279：109044.
[8] ZHANG H H，GUO Q L，WANG Y W，et al. Cross-scale analysis on the mechanical behavior of the conglomerate of Yulin Grottoes in China[J]. International Journal of Rock Mechanics and Mining Sciences，2024，178：105750.
[9] AKRAM M S，SHARROCK G B，MITRA R. Investigating mechanics of conglomeratic rocks：influence of clast size distribution， scale and properties of clast and interparticle cement[J]. Bulletin of Engineering Geology and the Environment，2019，78(4)：2 769–2 788.
[10] WANG J B，GE H K，LIU J T，et al. Effects of gravel size and content on the mechanical properties of conglomerate[J]. Rock Mechanics and Rock Engineering，2022，55(4)：2 493–2 502.
[11] LI J R，DUAN K，MENG H，et al. On the mechanical properties and failure mechanism of conglomerate specimens subjected to triaxial compression tests[J]. Rock Mechanics and Rock Engineering，2023，56(2)：973–995.
[12] SKEJI´C A，GAVRI´C D，JURIˇSI´C M，et al. Experimental and numerical analysis of axially loaded bored piles socketed in a conglomerate rock mass[J]. Rock Mechanics Rock Engineering，2022，55(10)：6 339–6 365.
[13] 魏 俊，廖华林，王华健，等. 真三轴条件下砾岩力学特性试验[J].中国石油大学学报：自然科学版，2022，46(5)：81–89.(WEI Jun，LIAO Hualin，WANG Huejian，et al. Experiment on mechanical properties of conglomerate rocks under true triaxial loading[J]. Journal of China University of Petroleum：Natural Science，2022，46(5)：81–89.(in Chinese))
[14] CHEN B，JI J Q，LIN J Q，et al. Experimental and numerical investigation of characteristics of highly heterogeneous rock mechanical responses in tight sandy conglomerate reservoir rock under triaxial compression[J]. Frontiers in Earth Science，2021，(9)：735208.
[15] 张兆鹏，张士诚，石善志，等. 基于纳米压痕实验和均匀化方法评价砾岩多尺度力学性质——以玛湖凹陷南斜坡致密砾岩储层为例[J]. 岩石力学与工程学报，2022，41(5)：926–940.(ZHANG Zhaopeng，ZHANG Shicheng，SHI Shanzhi，et al. Evaluation of multi-scale mechanical properties of conglomerate using nanoindentation and homogenization methods：a case study on tight conglomerate reservoirs in the southern slope of Mahu sag[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(5)：926–940.(in Chinese))
[16] JU Y，CHEN J L，WANG Y L，et al. Numerical analysis of hydrofracturing behaviors and mechanisms of heterogeneous reservoir glutenite，using the continuum-based discrete element method while considering hydromechanical coupling and leak-off effects. Journal of geophysical research[J]. Solid Earth，2018，123(5)：3 621–3 644.
[17] YANG Z F，CHIKAOSA T. Assessing the relative stability of the Mogao Grottoes using a rock mass quality classification approach[M]. [S. l.]：Ancient Underground Opening and Preservation，2016：261–268.
[18] 石玉成，王旭东，秋仁东，等. 敦煌莫高窟崖体锚索加固技术钻孔振动效应测试分析[J]. 世界地震工程，2007，(4)：7–12.(SHI Yucheng，WANG Xudong，QIU Rendong，et al. Vibration effect testing and analysis of anchor wire reinforcement of cliff rock mass of Mogao Grotto[J]. World Information on Earthquake Engineering，2007，(4)：7–12.(in Chinese))
[19] LIU H L，WANG X D，GUO Q L. Field testing study on the rainfall thresholds and prone areas of sandstone slope erosion at Mogao Grottoes，Dunhuang[J]. Environmental Monitoring and Assessment，2019，191(12)：755.
[20] 郭青林，王旭东，薛 平，等. 敦煌莫高窟底层洞窟岩体内水汽与盐分空间分布及其关系研究[J]. 岩石力学与工程学报，2009，28(增2)：3 769–3 775.(GUO Qinglin，WANG Xudong，XUE Ping，et al. Research on spatial distribution and relations of salinity and moisture content inside rock mass of low-layer caves in Dunhuang Mogao Grottoes[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(Supp.2)：3 769–3 775.(in Chinese))
[21] LI H S，WANG W F，ZHANG H T，et al. Water in the Mogao Grottoes，China：where it comes from and how it is driven[J]. Journal of Arid Land，2015，7(1)：37–45.
[22] 王旭东，张明泉，张虎元，等. 敦煌莫高窟洞窟围岩的工程特性[J].岩石力学与工程学报，2000，19(6)：756–761.(WANG Xudong，ZHANG Mingquan，ZHANG Huyuan，et al. Engineering properties of surrounding rock of Mogao grottoes at Dunhuang[J]. Chinese Journal of Rock Mechanics and Engineering，2000，19(6)：756–761.(in Chinese))
[23] 李最雄. 敦煌石窟保护工作六十年[J]. 敦煌研究，2004，(3)：10–26.(LI Zuixiong. Sixty years on the conservation of the Dunhuang Grottoes[J]. Dunhuang Research，2004，(3)：10–26.(in Chinese))
[24] GUO Q Q，WANG X D，LI Z X，et al. Damage and conservation of the high cliff on the Northern area of Dunhuang Mogao Grottoes，China[J]. Landslides，2009，6(2)：89–100.
[25] 崔 凯，顾 鑫，吴国鹏，等. 不同条件下贺兰口岩画载体变质砂岩干湿损伤特征与机制研究[J]. 岩石力学与工程学报，2021，40(6)：1 236–1 247.(CUI Kai，GU Xin，WU Guopeng，et al. Dry-wet damage characteristics and mechanism of metamorphic sandstone carrying Helan mouth's rock paintings under different conditions[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(6)：1 236– 1 247.(in Chinese))
[26] 朱建波，付乙梓，李 瑞，等. 干湿循环与动态压缩耦合作用下砂岩力学特性的试验研究[J]. 岩石力学与工程学报，2023，42(增1)：3 558–3 566.(ZHU Jianbo，FU Yixin，LI Rui，et al. Experimental study on mechanical characteristics of sandstone under drying wetting cycles and dynamic compression[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(Supp.1)：3 558–3 566.(in Chinese))
[27] AN R，KONG L W，ZHANG X W，et al. Effects of dry-wet cycles on three-dimensional pore structure and permeability characteristics of granite residual soil using X-ray micro-computed tomography[J]. Journal of Rock Mechanics and Geotechnical Engineering，2022，14(3)：851–860.
[28] 刘晓颖，郭青林，张 博，等. 降雪、温差作用下大尺寸砂岩风化模拟试验研究[J]. 岩石力学与工程学报，2024，43(6)：1 519–1 534. (LIU Xiaoying，GUO Qinglin，ZHAN Bo，et al. Simulation experiment study on large-size sandstone weathering under coupling effect of snow and temperature[J]. Chinese Journal of Rock Mechanics and Engineering，2024，43(6)：1 519–1 534.(in Chinese))
[29] 宋彦琦，马宏发，刘济琛，等. 冻融灰岩单轴声发射损伤特性试验研究[J]. 岩石力学与工程学报，2022，41(增1)：2 603–2 614.(SONG Yanqi，MA Hongfa，LIU Jichen，et al. Experimental investigation on the damage characteristics of freeze-thaw limestone by the uniaxial compression and acoustic emission monitoring tests[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(Supp.1)：2 603–2 614. (in Chinese))
[30] 贾海梁. 多孔岩石及裂隙岩体冻融损伤机制的理论模型和试验研究[博士学位论文][D]. 武汉：中国地质大学，2016.(JIA Hailiang. Theoretical damage models of porous rocks and hard jointed rocks subjected to frost action and further experimental verifications[Ph. D. Thesis][D]. Wuhan：China University of Geosciences，2016.(in Chinese))
[31] 贾 蓬，毛松泽，孙占阳，等. 冻融损伤砂岩的能量演化及分段本构模型[J]. 中南大学学报：自然科学版，2023，54(3)：908–919.(JIA Peng，MAO Songze，SUN Zhanyang，et al. Energy evolution and piecewise constitutive model of freeze-thaw damaged sandstone[J]. Journal of Central South University：Science and Technology，2023，54(3)：908–919.(in Chinese))
[32] 王旭东，张虎元，郭青林，等. 敦煌莫高窟崖体风化特征及保护对策[J]. 岩石力学与工程学报，2009，28(5)：1 055–1 063.(WANG Xudong，ZHANG Huyuan，GUO Qinglin，et al. Weathering characterization and conservation treatment of cliff at Mogao Grottoes[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(5)：1 055–1 063.(in Chinese))
[33] 叶 飞，谌文武，梁行洲，等. 敦煌莫高窟玉门组砂砾岩风化特征研究[J]. 工程地质学报，2016，24(6)：1 286–1 293.(YE Fei，CHEN Wenwu，LIANG Xingzhou，et al. Study on the weathering characteristics of the Yumen glutenite in the Mogao Grottoes in Dunhuang[J]. Journal of Engineering Geology，2016，24(6)：1 286–1 293.(in Chinese))
[34] 王彦武，王旭东，朱 毓，等. 甘肃瓜州榆林窟东崖体水分分布特征研究[J]. 兰州大学学报：自然科学版，2021，57(2)：238–243.(WANG Yanwu，WANG Xudong，ZHU Yu，et al. The moisture characteristics of surrounding rocks in the eastern Cliff of the Yulin Grottoes，Guazhou，Gansu Province[J]. Journal of Lanzhou University：Natural Science，2021，57(2)：238–243.(in Chinese))
[35] 王彦武. 甘肃典型石窟渗水机制与防治技术研究[博士学位论文][D]. 兰州：兰州大学，2024.(WANG Yanwu. Study on mechanism and prevention technology of water seepage of typical grottoes in gansu provincet[Ph. D. Thesis][D]. Lanzhou：Lanzhou University，2024.(in Chinese))
[36] 郭青林，薛 平，侯文芳，等. 安西榆林窟环境特征[J]. 敦煌研究，2002，(4)：102–109.(GUO Qinglin，XUE Ping，HOU Wenfang，et al. Environmental features of the Anxi Yulin Grottoes[J]. Dunhuang Research，2002，(4)：102–109.(in Chinese))
[37] 中华人民共和国行业标准编写组. SL/T 264—2020 水利水电工程岩石试验规程[S]. 北京：中国水利水电出版社，2020.(The Professional Standards Compilation Group of People?s Republic of China. SL/T 264—2020 Code for rock tests in water and hydropower projects[S]. Beijing：China Water Power Press，2020.(in Chinese))
[38] 张国凯，李海波，夏 祥，等. 岩石波速与损伤演化规律研究[J]. 岩石力学与工程学报，2015，34(11)：2 270–2 277.(ZHANG Guokai，LI Haibo，XIA Xiang，et al. Wave velocity and damage development of rock[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(11)：2 270–2 277.(in Chinese))
[39] 郑木莲. 多孔混凝土的渗透系数及测试方法[J]. 交通运输工程学报，2006，(4)：41–46.(ZHENG Mulian. Permeability coefficient and test method of porous concrete[J]. Journal of Traffic and Transportation Engineering，2006，(4)：41–46.(in Chinese))
[40] CHEN W W，LIAO R X，WANG N，et al. Effects of experimental frost-thaw cycles on sandstones with different weathering degrees：a case from the Bingling Temple Grottoes，China[J]. Bulletin of Engineering Geology and the Environment，2019，78(7)：5 311–5 326.
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