Freeze-thaw deterioration of saline earthen sites under snowmelt or rainfall infiltration

被引：0

作者：

Chen W.-W. ^{[1
,2
]}

Jia B.-B. ^{[1
]}

Cai T. ^{[1
]}

Chen H.-X. ^{[1
]}

Li X. ^{[1
]}

机构：

[1] School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou

[2] Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou

来源：

Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | 2022年 / 44卷 / 02期

关键词：

Freeze-thaw deterioration; Microstructure; Rainfall infiltration; Saline earthen site; Snowmelt infiltration;

D O I：

10.11779/CJGE202202015

中图分类号：

学科分类号：

摘要：

The changes of samples after freeze-thaw cycles under the initial conditions of snowmelt or rainfall infiltration are characterized considering the water content, conductivity, elastic wave velocity and unconfined compressive strength. Furthermore, the freeze-thaw deterioration mechanism of the saline earthen sites is studied based on the macroscopic and microstructure changes of the samples. The results show that during the freeze-thaw cycles, the water content of the samples increases first, then decreases and tends to be stable due to the water supply and evaporation loss of snowmelt and rainfall infiltration, and after migration with water, the salt is enriched at the height of 5 and 3.5 cm, respectively. The supplied water increases the thickness of bound water film between soil particles, and the elastic wave velocity and unconfined compressive strength of the samples decrease significantly. With the progress of freeze-thaw cycles, the water evaporates, and the wave velocity and strength of the samples increase gradually. The salt content and precipitation form are the key factors affecting the strength recovery of the samples. When its content is more than 0.4%, the increase of the content of Na2SO4 will reduce the strength recovery ratio of the samples. The addition of NaCl improves the strength recovery ratio of the samples, but slows down the strength recovery rate. After 12 freeze-thaw cycles, the snowmelt infiltration makes the soluble salt fully disperse in the samples, which is conducive to the recovery of soil, the accumulation of water and salt at the top of the samples leads to the formation of salt efflorescence and rolled mud. The rainfall infiltration makes microcracks develop and the proportion of macropores (> 16 μm) increase, the accumulation of water and salt at the wetting front leads to transverse cracks at the side of the samples, and the strength recovery speed and amplitude of the samples are small. © 2022, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.

引用

页码：334 / 342

页数：8

共 23 条

[1] FUJII Y, FODDE E, WATANABE K, Et al., Digital photogrammetry for the documentation of structural damage in earthen archaeological sites: The case of Ajina Tepa, Tajikistan, Engineering Geology, 105, 1, pp. 124-133, (2009)
[2] CUI Kai, GUAN Xi-peng, CHEN Wen-wu, Et al., Effects of salinized deterioration and aeolian ullage on soils in undercutting areas of earthern Ruins in arid regions(Ⅱ), Chinese Journal of Geotechnical Engineering, 39, 10, pp. 1777-1784, (2017)
[3] RICHARDS J, ZHAO G, ZHANG H, Et al., A controlled field experiment to investigate the deterioration of earthen heritage by wind and rain, Heritage Science, 7, (2019)
[4] SHAO M S, LI L, WANG S J, Et al., Deterioration mechanisms of building materials of Jiaohe Ruins in China, Journal of Cultural Heritage, 14, 1, pp. 38-44, (2013)
[5] MAO W J, SHEN Y X, ZHU Y P, Et al., Disentangling the deformation process of earthen sites and understanding the role of Na<sub>2</sub>SO<sub>4</sub> and precipitation: a case study on the Great Wall Relics of the Ming dynasty in Yulin, China, Studies in Conservation, 66, 1, pp. 51-63, (2021)
[6] OZGAN E, SERIN S, ERTURK S, Et al., Effects of freezing and thawing cycles on the engineering properties of soils, Soil Mechanics and Foundation Engineering, 52, 2, pp. 95-99, (2015)
[7] YE Wan-jun, YANG Geng-she, PENG Jian-bing, Et al., Test research on mechanism of freezing and thawing cycle resulting in loess slope spalling hazards in Luochuan, Chinese Journal of Rock Mechanics and Engineering, 31, 1, pp. 199-205, (2012)
[8] PU T B, CHEN W W, DU Y M, Et al., Snowfall-related deterioration behavior of the Ming Great Wall in the eastern Qinghai-Tibet Plateau, Natural Hazards, 84, 3, pp. 1539-1550, (2016)
[9] CUI K, WU G P, DU Y M, Et al., The coupling effects of freeze-thaw cycles and salinization due to snowfall on the rammed earth used in historical freeze-thaw cycles relics in northwest China, Cold Regions Science and Technology, 160, pp. 288-299, (2019)
[10] WANG X D, ZHANG B, PEI Q Q, Et al., Experimental studies on sacriﬁcial layer in conservation of earthen sites, Journal of Cultural Heritage, 41, pp. 74-83, (2020)

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