Soil-water characteristics and pore-size distribution of lateritic clay

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1 DOI /CJGE MPa 10 MPa TU43 A (2015) (1962 ) sundean@shu.edu.cn Soil-water characteristics and pore-size distribution of lateritic clay SUN De-an 1, 2, GAO You 1, LIU Wen-jie 1, WEI Chang-fu 2, ZHANG Sheng 3 (1. Department of Civil Engineering, Shanghai University, Shanghai , China; 2. Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering, Guilin University of Technology, Guilin , China; 3. School of Civil Engineering, Central South University, Changsha , China) Abstract: The pressure plate method, filter paper method and vapor equilibrium technique with saturated salt solution and mercury intrusion porosimetry tests on Guilin lateritic clay are used to investigate the soil-water characteristics and pore-size distribution of undisturbed and compacted specimens in full suction range. The test results show that the undisturbed specimen has lower water content and saturation degree than the compacted one in the suction ranging from 0 kpa to 10 MPa because of the development of internal crack of undisturbed specimen with the increasing suction. When the suction is higher than 10 MPa, the soil-water characteristic curves (SWCC) coincide with each other. In the transition zone, the SWCCs of the undisturbed and compacted specimens are different from the typical ones. The undisturbed natural specimens exhibit a unimodal pore-size distribution, and the compacted ones usually have a double-porosity microstructure. The stability of shrinkage of the undisturbed natural specimen is larger than that of the compacted one. The compacted specimens with different dry densities also have the same pore-size distribution between particles, while the inter-aggregate pore distribution differ between the compacted specimens with different dry densities. It explains that when it is expressed by the relation between suction and water content, the SWCC is independent of dry density in the high suction range. When it is expressed by the relation between suction and saturation degree, the SWCC with high dry density is higher than that with the small one. Key words: soil-water characteristic curve; lateritic clay; mercury intrusion porosimetry; pore-size distribution; undisturbed specimen [1] CB KF

2 [2] [3] [4] [5] [6] [7] 01.5 MPa MPa 3367 MPa X 56.59%11.44% 15.61%12.45% 2 μm 50.8% [8] 61.8 mm 20 mm 32.1% 1.4 g/cm 3 2 mm 32.1% g/cm 3 28% 77.8% 42.1% % 1.7% 1.7% kpa 21.9 GCTS SWC bar 1.5 MPa SWC MPa 7 32 % 1.4 g/cm 3 7 7%32% Lock&Lock 3 Whatman No.42 [9] 8 15 min [10] 1 20 Table 1 Saturated salt solution and corresponding suctions RH/% /MPa LiBr LiCl H 2 O CH 3 COOK MgCl 2 6H 2 O K 2 CO NaBr KI NaCl KCL K 2 SO g/cm 3

2. 353 1 3 10 kpa 101.0 MPa 1.010 MPa 10 MPa 1c Fig.

3 kpa MPa MPa 10 MPa 1c Fig. 1 SWCCs and void ratios of undisturbed lateritic clay in full suction range 2 Fig. 2 Undisturbed and compacted specimens after air-drying 1.0 MPa 1.0 MPa 3 3 3ab 20 kpa 3 10 MPa 2 10 MPa 3c 1 MPa 3a 3c

4 p(d)pad m T s N/m [12-13] Micromeritics AutoPore IV 4207 kpa kpa 4 Fig. 3 SWCCs and void ratios of undisturbed and compacted specimens in full suction range p(d) d Wash burn [11] 4Ts cos pd ( ) (1) d Fig. 4 Relationship between diameter and cumulative intruded volume μm

5 c Kodikara [14] μm 130 μm μm Fig. 5 Relationship between diameter and density of pore-size distribution μm 5500 μm 6a 6b 6a 6b Fig. 6 Soil-water characteristic curves of compacted lateritic clay with two dry densities in wetting MPa 10 MPa 3 4

6 [1]. [J]., 2000, 3: (JIANG Hong-tao. Origin of red clay and its effects on engineering property[j]. Hydrogeology and Engineering Geology, 2000, 3: (in Chinese)) [2],. [J]., 2001, 33(4): (TAN Luo-rong, KONG Ling-wei. Fundamental property and micro structure model of red clay[j]. Chinese Journal of Geotechnical Engineering, 2001, 33(4): (in Chinese)) [3],,,. [J]., 2004, 25(3): (ZHAO Ying-wen, KONG Ling-wei, GUO Ai-guo, et al. Strength properties and swelling-shrinkage behavior of compacted lateritic clay in Guangxi[J]. Rock and Soil Mechanics, 2004, 25(3): (in Chinese)) [4],,. [J], 2003, 24(1): (YANG Qing, HE Jie, LUAN Mao-tian. Comparative study on shear strength of unsaturated red clay and expansive soils[j]. Rock and Soil Mechanics, 2003, 24(1): (in Chinese)) [5],,,. [J]., 2011, 32( 1): (TAN Yun-zhi, KONG Ling-wei, GUO Ai-guo, et al. Analysis of water holding capacity and mechanism of compacted laterite soil[j]. Rock and Soil Mechanics, 2011, 32(S1): (in Chinese)) [6],,. [J]., 2009, 30(11): (LIU Xiao-we, CHANG Li-jun, HU Xiao-rong. Experimental research of matric suction with water content and dry density of unsaturated laterite[j]. Rock and Soil Mechanics, 2009, 30(11): (in Chinese)) [7],,,. [J]., 2004, 23(15): (ZHAO Ying-wen, KONG Ling-wei, GUO Ai-guo, et al. Comparative laboratory study on typical red clay and expansive soil[j]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(15): (in Chinese)) [8],,,. [J]., 2012, 20(5): (LÜ Hai-bo, ZENG Zhao-tian, YIN Guo-qiang, et al. Analysis of mineral composition of red clay in Guangxi[J]. Journal of Engineering Geology, 2012, 20(5): (in Chinese)) [9],,,. [J]., 2011, 32(4): (SUN De-an, MENG De-lin, SUN Wen-jing, et al. Soil-water characteristic curves of two bentonites[j].rock and Soil Mechanics, 2011, 32(4): (in Chinese) ) [10] GREESPAN L. Humidity fixed points of binary saturated aqueous solutions[j]. Journal of Research of the National Bureau of Standards, 1977, 81(1): [11] WASHBURN E W. Note on a method of determining the distribution of pore sizes in a porous material[j]. Proceedings of the National Academy of Sciences of the United States of America, 1921, 7(4): [12],,,. [J]., 2011, 32(1): (ZHANG Ping, FANG Ying-guang, YAN Xiao-qing, et al. Study of different dry methods for drying remolded bentonite sample with mercury intrusion test[j]. Rock and Soil Mechanics, 2011, 32(1): (in Chinese)) [13] SASANIAN S, NEWSON T A. Use of mercury intrusion porosimetry for microstructural investigation of reconstituted clays at high water contents [J]. Engineering Geology, 2013, 158: [14] KODIKARA J, BARBOUR S L, FREDLUND D G. Change in clay structure behaviour due to wetting and drying[c]// Proceedings of 8th Australian-Zealand Conference on Geomechanics. Hobart, 1999:

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