Experimental study on contact angle and pore characteristics of unsaturated loess

Authors

JING Yanlin, School of Civil Engineering, Chang'an University, Xi'an 710061, China
WANG Hao, School of Civil Engineering, Chang'an University, Xi'an 710061, China
TAO Chunliang, School of Civil Engineering, Chang'an University, Xi'an 710061, China
YANG Lina, China JIKAN Research Institute of Engineering Investigations and Design Co. Ltd., Xi'an 710043, China
LIU Jianwei, School of Civil Engineering, Chang'an University, Xi'an 710061, China
WEN Xin, School of Civil Engineering, Chang'an University, Xi'an 710061, China

Abstract

Contact angle and pore size are important factors affecting soil wettability, permeability and capillarity. In order to further understand the capillary characteristics and permeability of unsaturated loess, the contact angle test and mercury intrusion test of unsaturated loess were carried out. The relationship between pore size and contact angle was analyzed in details. Moreover, the variation of pore and contact angle with depth was discussed. It is found that the contact angle of loess in the dry state is higher than the contact angle of loess in the natural state; as the depth of the formation increases, the contact angle increases; the contact angle is negatively correlated with the large and medium pore volume, whereas is positively correlated with the micropore volume. Additionally, in the shallow part of the stratum, the contact angle is positively correlated with the small pore volume, while for the deep stratum, the contact angle is negatively correlated with the small pore volume. In unsaturated loess, the content of small pores and micropores is relatively large, while the content of large and medium pores is relatively small.

Keywords

unsaturated loess, pore feature, contact angle, capillarity

DOI

10.3969/j.issn.1001-1986.2019.05.022

Recommended Citation

JING Yanlin, WANG Hao, TAO Chunliang, et al. (2019) "Experimental study on contact angle and pore characteristics of unsaturated loess," Coal Geology & Exploration: Vol. 47: Iss. 5, Article 23.
DOI: 10.3969/j.issn.1001-1986.2019.05.022
Available at: https://cge.researchcommons.org/journal/vol47/iss5/23

Reference

[1] KIM Myeongsoo,KIM Gunhwi,KIM Jinyoung,et al. New continuous process developed for synthesizing sponge-type polyimide membrane and its pore size control method via non-solvent induced phase separation(NIPS)[J]. Microporous and Mesoporous Materials,2017,242:166-172.

[2] 赵明华. 土力学与基础工程[M]. 武汉:武汉理工大学出版社,2009.

[3] SCHELLBACH S L,MONTEIRO S N,JAROSLAW W D. A novel method for contact angle measurements on natural fi-bers[J]. Materials Letters,2016,164:599-604.

[4] LOURENCO S D N,SAULICK Y,ZHENG S,et al. Soil wettability in ground engineering:Fundamentals,methods,and applications[J]. Acta Geotechnica,2018,13(1):1-14.

[5] MOSCARIELLO M,CUOMO S,SALAGER S,et al. Capillary collapse of loose pyroclastic unsaturated sands characterized at grain scale[J]. Acta Geotechnica,2018,13(1):117-133.

[6] 邓石桥,任露泉,韩志武. 土壤-犁壁界面毛细负压的形成和作用[J]. 吉林大学学报(工学版),2004,34(3):517-520. DENG Shiqiao,REN Luquan,HAN Zhiwu. Formation of capillary negative air pressure on interface of soil-moldboard and its function[J]. Journal of Jilin Univer-sity(Engineering Science),2004,34(3):517-520.

[7] 栗现文,周金龙,周念清,等. 潜水高矿化度对粉质粘土毛细水上升的影响[J]. 干旱区资源与环境,2016,30(7):192-196. LI Xianwen,ZHOU Jinlong,ZHOU Nianqing,et al. Effects of high TDS on capillary rise of phreatic water in silty clay soil[J]. Journal of Arid Land Resources and Environment,2016,30(7):192-196.

[8] 魏样,王益权,蔡苗,等. 石油污染对土壤毛细水上升特性的影响[J]. 灌溉排水学报,2017,36(9):50-56 WEI Yang,WANG Yiquan,CAI Miao,et al. Impact of soil contamination with oil on capillary water rise[J]. Journal of Irrigation and Drainage,2017,36(9):50-56.

[9] LIU Sai,LI Shanpeng,LIU Jianlin. Jurin's law revisited:Exact meniscus shape and column height[J]. the European Physical Journal E,2018,41:46. doi 10.1140/epje/i2018-11648-1.

[10] 袁玉卿,李伟,赵丽敏. 豫东黄泛区粉砂土毛细水上升研究[J]. 公路交通科技,2016,33(2):33-38. YUAN Yuqing,LI Wei,ZHAO Limin. Research of silty soil capillary water rising in Yellow river flooded area of eastern Henan[J]. Journal of Highway and Transportation Research and Development,2016,33(2):33-38.

[11] HIRD R,BOLTON M D. Clarification of capillary rise in dry sand[J]. Engineering Geology,2017,230:77-83.

[12] 杨松,龚爱民,吴珺华,等. 接触角对非饱和土中基质吸力的影响[J]. 岩土力学,2015,36(3):674-678. YANG Song,GONG Aimin,WU Yuhua,et al. Effect of contact angle on matric suction of unsaturated soil[J]. Rock and Soil Mechanics,2015,36(3):674-678.

[13] GREENSPAN H P. On the motion of a small viscous droplet that wets a surface[J]. Journal of Fluid Mechanics,1978,84(1):125-143.

[14] 王晓东,彭晓峰,陆建峰,等. 接触角测试技术及粗糙表面上接触角的滞后性Ⅰ:接触角测试技术[J]. 应用基础与工程科学学报,2003,11(2):174-184. WANG Xiaodong,PENG Xiaofeng,LU Jianfeng,et al. Contact angle test technology and hysteresis of contact angle on rough surface I:Contact angle test technology[J]. Journal of Basic Science and Engineering,2003,11(2):174-184.

[15] 王晓东,彭晓峰,陆建峰,等. 接触角测试技术及粗糙表面上接触角的滞后性Ⅱ:粗糙不锈钢表面接触角的滞后性[J]. 应用基础与工程科学学报,2003,11(3):296-303. WANG Xiaodong,PENG Xiaofeng,LU Jianfeng,et al. Contact angle testing technology and hysteresis of contact angle on rough surface II:Hysteresis of contact angle of rough stainless steel surface[J]. Journal of Basic Science and Engineering,2003,11(3):296-303.

[16] 刘培生. 多孔材料比表面积和孔隙形貌的测定方法[J]. 稀有金属材料与工程,2006,35(增刊2):25-29. LIU Peisheng. Determination of specific surface area and pore morphology of porous materials[J]. Rare Metal Materials and Engineering,2006,35(S2):25-29.

[17] SMEDLEY G T,COLES D E. A refractive tilting-plate technique for measurement of dynamic contact angles[J]. Journal of Colloid and Interface Science,2005,286(1):310-318.

[18] 曹晓平,蒋亦民. 浸润接触线的摩擦性质与固体表面张力的Wenzel行为[J]. 物理学报,2005,54(5):2202-2206. CAO Xiaoping,JIANG Yimin. Frictional properties of wetting contact line and Wenzel's behavior of solid surface tension[J]. Chinese Journal of Physics,2005,54(5):2202-2206.

[19] 刘建维. 面向润湿作用的黄土结构性及吸附特性试验研究[D]. 西安:长安大学,2017.

[20] 滕新荣. 表面物理化学[M]. 北京:化学工业出版社,2009.

[21] 雷祥义. 中国黄土的孔隙类型与湿陷性[J]. 中国科学(B辑),1987,17(12):1309-1318. LEI Xiangyi. Pore types and collapsible loess in China,China[J]. Science in China(Series B),1987,17(12):1309-1318.

[22] 中华人民共和国建设部. GB/T 50123-1999土工试验方法标准[S]. 北京:中国计划出版社,1999.