岩体表层凝结水的形成与转化规律:对岩石风化水分来源的指示意义

doi:10.13745/j.esf.sf.2022.2.15

地学前缘 ›› 2023, Vol. 30 ›› Issue (2): 506-513.DOI: 10.13745/j.esf.sf.2022.2.15

• 表层地球系统与生态环境效应 • 上一篇下一篇

岩体表层凝结水的形成与转化规律:对岩石风化水分来源的指示意义

欧阳恺皋¹(), 蒋小伟¹^,^*(), 马策¹, 闫宏彬², 任建光², 樊尧², 张润平², 付前方³, 李旭³, 万力¹

1.中国地质大学(北京) 水资源与环境学院, 北京 100083
2.云冈研究院, 山西大同 037034
3.北京原真在线监测技术有限公司, 北京 102218

收稿日期:2021-09-10 修回日期:2021-11-12 出版日期:2023-03-25 发布日期:2023-01-05
通讯作者: 蒋小伟
作者简介:欧阳恺皋(1999—),男,硕士研究生,水利工程专业,主要从事包气带水汽运移方面研究工作。E-mail: 2005210054@email.cugb.edu.cn
基金资助:
国家重点研发计划项目(2019YFC1520500);山西省文物局文物保护科技项目(208141400237)

Formation and transformation of condensate water inside rocks: Insight into source of rock moisture affecting weathering

OUYANG Kaigao¹(), JIANG Xiaowei¹^,^*(), MA Ce¹, YAN Hongbin², REN Jianguang², FAN Yao², ZHANG Runping², FU Qianfang³, LI Xu³, WAN Li¹

1. School of Water Resources and Environment, China University of Geosciences(Beijing), Beijing 100083, China
2. Yungang Research Institute, Datong 037034, China
3. Beijing OUV Online Technology Co., LTD, Beijing 102218, China

Received:2021-09-10 Revised:2021-11-12 Online:2023-03-25 Published:2023-01-05
Contact: JIANG Xiaowei

摘要/Abstract

摘要：

水对岩石风化具有重要控制作用,但人们对非露天岩石表层的水分来源一直认识不足。本文以我国北方云冈石窟的岩石壁面为例,利用频域反射技术开展了岩石浅表层含水率监测,利用2020年5月至2021年5月逐小时的岩石视含水率数据为例,识别了夏季和冬季岩石含水率波动的控制机理。从6月初到10月初,大气湿度变化是岩石视含水率先增大后减小的直接控制因素,当存在指向山体内部的大气湿度梯度时,水汽迁移至岩石孔隙内,发生毛细凝聚转变为液态水,从而引起视含水率增大;当存在指向山体外部的大气湿度梯度时,岩石孔隙内的液态水蒸发,从而引起岩石视含水率下降。从10月中旬至次年6月初,岩石普遍较干燥,但是12月中旬浅部岩石含水率在冻结吸力控制下还是会发生明显增大现象,表明岩石中存在可迁移、可发生化学风化的弱结合水。本研究识别了非露天石质文物壁面水分的一种重要来源,加深了对凝结水形成机理及其对风化控制作用的认识,可为石质文物保护提供决策依据。

关键词: 岩石风化, 空气湿度, 岩石含水率, 凝结水, 毛细凝聚, 频域反射技术, 云冈石窟

Abstract:

Water plays an important role in controlling rock weathering, but there is still limited understanding of the source of rock moisture in rocks not directly exposed to sunshine and rainfall. In this study, a cave wall of the Yungang Grottoes in northern China is selected as an example for rock moisture measurement using the frequency domain reflection (FDR) method. Using the hourly monitoring data on the apparent rock water content at the rockwall between May 2020 to May 2021, different mechanisms controlling rock moisture fluctuations in summer and winter are identified. From early June to early October, the change of atmospheric humidity is the direct controlling factor for the increase and decrease of the rock moisture at the rockwall. Specifically, when atmospheric humidity gradient points to the interior of the mountain, water vapor migrates into the porous rock and condenses into liquid water, which increases rock moisture; inversely, liquid water within the rock evaporates thus decreases rock moisture. From middle October to early June, although the rock is relatively dry, the apparent rock water content of the rockwall surface layer still increases significantly in mid-December via cryosuction-induced water migration. This indicates that there is weakly bound water in the rockwall which can migrate and promote chemical weathering. By identifying an important moisture source in stone heritages, this study deepens the understanding of the rock weathering mechanism, and provides a decision-making basis for the conservation of stone heritages.

Key words: rock weathering, humidity, rock moisture, condensate water, capillary condensation, the Yungang Grottoes

中图分类号:

P512.1

欧阳恺皋, 蒋小伟, 马策, 闫宏彬, 任建光, 樊尧, 张润平, 付前方, 李旭, 万力. 岩体表层凝结水的形成与转化规律:对岩石风化水分来源的指示意义[J]. 地学前缘, 2023, 30(2): 506-513.

OUYANG Kaigao, JIANG Xiaowei, MA Ce, YAN Hongbin, REN Jianguang, FAN Yao, ZHANG Runping, FU Qianfang, LI Xu, WAN Li. Formation and transformation of condensate water inside rocks: Insight into source of rock moisture affecting weathering[J]. Earth Science Frontiers, 2023, 30(2): 506-513.

图/表 6

图1 云冈石窟某洞窟壁面夏季的凝结水分布(拍摄于2021年7月12日)

Fig.1 Photo of a cave wall at the Yungang Grottoes showing the features of condensate water on the wall surface (photo taken on July 12, 2021)

图2 气温、大气相对湿度数据和绝对湿度的变化规律

Fig.2 Temporal variation trends of ambient temperature and relative and absolute atmospheric humidities between May 2020-May 2021

图3 岩体表层视含水率、窟外大气绝对湿度、壁温随时间变化规律

Fig.3 Temporal variation trends of apparent rock water content at wallrock surface layer, absolute atmospheric humidity outside the cave and rockwall temperature (May 2020-May 2021)

图4 2020年夏季岩石浅表层视含水率与绝对湿度差对比

Fig.4 Relationship between apparent rock water content at the rockwall surface layer and absolute humidity difference inside or outside of cave in the summer months of 2020

图5 夏季岩石浅表层视含水率典型上升段中视含水率增大幅度和绝对湿度差累计值、降雨量相关关系

Fig.5 Correlations between increase of rock water content at rockwall surface layer and humidity or rainfall during typical moisture rising periods in summer. (a) Plot of rock water content increase vs. cumulative absolute humidity difference between inside and outside of cave during each period. (b) Plot of rock water content increase vs. rainfall during each period.

图6 2020年夏季两个时间段内岩石视含水率上升段与露点、壁温对比

Fig.6 Comparison of temporal variations of rockwall dew point, temperature and rock water content between two moisture rising periods in the summer of 2020

参考文献 40

[1]	HUGGETT R J. Fundamentals of Geomorphology, 3rd edition[M]. New York: Routledge, 2011.
[2]	APPELO C A J, POSTMA D. Geochemistry, groundwater and pollution[M]. Rotterdam: A. A. Balkema, 2005.
[3]	熊志方, 龚一鸣. 北戴河红色风化壳地球化学特征及气候环境意义[J]. 地学前缘, 2006, 13(6): 177-186.
[4]	汪新文. 地球科学概论[M]. 北京: 地质出版社, 1999.
[5]	刘强. 石质文物保护[M]. 北京: 科学出版社, 2012.
[6]	黄继忠, 袁道先, 万力, 等. 水岩作用对云冈石窟石雕风化破坏的化学效应研究[J]. 敦煌研究, 2010(6): 59-63.
[7]	安程. 石窟环境监测模拟及整体性研究研究[M]. 北京: 科学出版社, 2019.
[8]	侯志鑫, 者瑞, 张中俭. 砂岩质文物风化机理研究: 以云冈石窟为例[J]. 工程勘察, 2020, 48(9): 1-5, 18.
[9]	方云, 乔梁, 陈星, 等. 云冈石窟砂岩循环冻融试验研究[J]. 岩土力学, 2014, 35(9): 2433-2442.
[10]	HALL K, HALL A. Weathering by wetting and drying: some experimental results[J]. Earth Surface Processesand Landforms, 1996, 21(4): 365-376.
[11]	TURKINGTON A V, PARADISE T R. Sandstone weathering: a century of research and innovation[J]. Geomorphology, 2005, 67(1/2): 229-253. DOI URL
[12]	黄克忠. 水在云冈石窟中的危害及防治[C]// 文物保护技术(1981—1991). 北京: 科学出版社, 2010: 284-290.
[13]	黄继忠. 世界文化遗产云冈石窟的防水保护[J]. 文物保护与考古科学, 2008, 20(增刊1): 114-121.
[14]	曹文炳, 万力, 曾亦键, 等. 云冈石窟洞窟内凝结水形成机制与防治研究[C]// 2005年云冈国际学术研讨会论文集(保护卷). 北京: 文物出版社, 2005:191-198.
[15]	王旭升, 万力, 彭涛, 等. 云冈石窟入渗水的形成和运移[J]. 工程勘察, 2012, 40(11): 12-16.
[16]	方云, 黄璇, 王晓东, 等. 龙门石窟潜溪寺凝结水定量测试研究[J]. 现代地质, 2011, 25(6): 1214-1218.
[17]	LI H S, WANG W F, ZHAN 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. DOI
[18]	朱华, 杨刚亮, 方云, 等. 龙门石窟潜溪寺凝结水病害形成机理及防治对策研究[J]. 中原文物, 2008(4): 109-112.
[19]	SASS O. Rock moisture measurements: techniques, results, and implications for weathering[J]. Earth Surface Processes and Landforms, 2005, 30(3): 359-374. DOI URL
[20]	REMPE D M, DIETRICH W E. Direct observations of rock moisture, a hidden component of the hydrologic cycle[J]. Proceedings of the National Academy of Sciences of the United States of America, 2018, 115(11): 2664-2669. DOI PMID
[21]	SCHMIDT L, REMPE D. Quantifying dynamic water storage in unsaturated bedrock with borehole nuclear magnetic resonance[J]. Geophysical Research Letters, 2020, 47(22), e2020GL089600.
[22]	万力, 曹文炳, 王旭升, 等. 云冈石窟水汽转化特征的初步研究[J]. 工程勘察, 2012, 40(11): 6-11.
[23]	黄继忠, 万力, 彭涛, 等. 云冈石窟水分来源探查工程及若干成果[J]. 工程勘察, 2012, 40(11): 1-5, 11.
[24]	甘向明. 云冈石窟凝结水研究与防治[D]. 北京: 中国地质大学(北京), 2006.
[25]	COOPER J D. Soil Water Measurement: A Practical Handbook[M]. Oxford: John Wiely and Sons, Ltd. 2016.
[26]	MOLLO L, GRECO R. Moisture measurements in masonry materials by time domain reflectometry[J]. Journal of Materials in Civil Engineering, 2011, 23 (4): 441-444. DOI URL
[27]	SAKAKI T, RAJARAM H. Performance of different types of time domain reflectometry probes for water content measurement in partially saturated rocks[J]. Water Resources Research, 2006, 42(7): W07404.
[28]	ČERNÝ R. Time-domain reflectometry method and its application for measuring moisture content in porous materials: a review[J]. Measurement, 2009, 42(3): 329-336. DOI URL
[29]	郭卫华, 李波, 张新时, 等. FDR系统在土壤水分连续动态监测中的应用[J]. 干旱区研究, 2003, 20(4): 247-251.
[30]	VAZ C M P, JONES S, MEDING M, et al. Evaluation of standard calibration functions for eight electromagnetic soil moisture sensors[J]. Vadose Zone Journal, 2013, 12(2): 332-338.
[31]	LU N, LIKOS W J. Unsaturated soil mechanics[M]. Hoboken: John Wiley, 2004.
[32]	LAWRENCE D S. Physical hydrology[M]. Upper Saddle River: Prentice Hall, 2002.
[33]	刘海康, 张思渊, 张鑫鑫. 不同初始含水率下砂岩冻融劣化特性试验研究[J]. 科学技术与工程, 2017, 17(26): 322-327.
[34]	黄继忠, 郑伊, 张悦, 等. 云冈石窟砂岩水汽扩散特性研究[J]. 西北大学学报(自然科学版), 2021, 51(3): 370-378.
[35]	HEATH J E, BRYAN C R, MATTEO E N, et al. Adsorption and capillary condensation in porous media as a function of the chemical potential of water in carbon dioxide[J]. Water Resources Research, 2014, 50(3): 2718-2731. DOI URL
[36]	TULLER M, OR D, DUDLEY L M. Adsorption and capillary condensation in porous media: liquid retention and interfacial configurations in angular pores[J]. Water Resources Research, 1999, 35(7): 1949-1964. DOI URL
[37]	许兆义, 王连俊, 杨成永. 工程地质基础[M]. 北京: 中国铁道出版社, 2003.
[38]	SUMNER P D, LOUBSER M J. Experimental sandstone weathering using different wetting and drying moisture amplitudes[J]. Earth Surface Processes and Landforms, 2008, 33(6): 985-990. DOI URL
[39]	DEPREZ M, DE KOCK T D, DE SCHUTTER G D, et al. A review on freeze-thaw action and weathering of rocks[J]. Earth Science Reviews, 2020, 203: 103143. DOI URL
[40]	唐大雄, 刘佑荣, 张文殊, 等. 工程岩土学[M]. 北京: 地质出版社, 1999.

岩体表层凝结水的形成与转化规律:对岩石风化水分来源的指示意义

Formation and transformation of condensate water inside rocks: Insight into source of rock moisture affecting weathering

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 6

参考文献 40

相关文章 2

编辑推荐

Metrics

本文评价

[1]	易泽邦, 付伟, 赵芹, 许成, 陆济璞. 花岗岩风化壳中稀土纳米微粒的提取、表征及赋存状态研究[J]. 地学前缘, 2022, 29(1): 42-53.
[2]	徐则民. 温湿气候区结晶岩与碎屑岩腐岩特征及其发育过程[J]. 地学前缘, 2009, 16(3): 364-373.