Water Science and Engineering 2014, 7(3) 319-330 DOI:   doi:10.3882/j.issn.1674-2370.2014.03.007  ISSN: 1674-2370 CN: 32-1785/TV

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Keywords
structurally intact loess
remolded loess
tensile strength
shear strength
shear path
failure envelope of principal stress ( Kf line)
strength failure envelope
joint strength formula
Authors
LI Rong-Jian
ZHENG Wen
YAN Juan
LIU Jun-Ding
SHAO Sheng-Jun
PubMed
Article by Li,R.J
Article by Zheng,w
Article by Yan,j
Article by Liu,J.D
Article by Shao,S.J

Characteristics of structural loess strength and preliminary framework for joint strength formula

Rong-jian LI*1, 2, Jun-ding LIU1, Rui YAN1, Wen ZHENG1, Sheng-jun SHAO1

1. Institute of Geotechnical Engineering, Xi’an University of Technology, Xi’an 710048, P. R. China
2. Open Research Laboratory of Geotechnical Engineering, Ministry of Land and Resources, Chang’an University, Xi’an 710064, P. R. China

Abstract

    The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress ( line), and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests: the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural loess comprehensively and reasonably, a joint strength formula for structural loess was established. This formula comprehensively considers tensile and shear properties. Studies have shown that the tensile strength exhibits a decreasing trend with increasing water content. When the water content is constant, the tensile strength of the structurally intact soil is greater than that of remolded soil. In the studies, no loss of the originally cured cohesion in the structurally intact soil samples was observed, given that the soil samples did not experience loading disturbance during the uniaxial compressive strength test, meaning there is a high initial structural strength. The results of the conventional triaxial shear strength test show that the water content is correlated with the strength of the structural loess. When the water content is low, the structural properties are strong, and when the water content is high, the structural properties are weak, which means that the water content and the ambient pressure have significant effects on the stress-strain relationship of structural loess. The established joint strength formula of structural loess effectively avoids overestimating the role of soil tensile strength in the traditional theory of Mohr-Coulomb strength.

Keywords structurally intact loess   remolded loess   tensile strength   shear strength   shear path   failure envelope of principal stress ( Kf line)   strength failure envelope   joint strength formula  
Received 2013-03-12 Revised 2013-11-02 Online: 2014-07-25 
DOI: doi:10.3882/j.issn.1674-2370.2014.03.007
Fund:
This work was supported by the National Natural Science Foundation of China (Grant No. 11072193), the Fundamental Research Funds for the Central Universities (Grant No. 2013G1502009), and the China Postdoctoral Science Foundation (Grant No. 20100481354).
Corresponding Authors: Rong-jian LI
Email: lirongjian@xaut.edu.cn
About author:

References:

Consoli, N., Cruz, R., Floss, M., and Festugato, L. 2010. Parameters controlling tensile and compressive strength of artificially cemented sand. Journal of Geotechnical and Geoenvironmental Engineering, 136(5), 759-763. [doi:10.1061/(ASCE)GT.1943-5606.0000278]
Hu, C. M., Mei, Y., and Wang, X. Y. 2013. Deformation and shear strength characteristic of compacted Malan Loess in Lüliang region. Engineering Mechanics, 30(10), 108-114. (in Chinese) [doi:10.6052/ j.issn.1000-4750.2012.06.0441]
Ibarra, S. Y., McKyes, E., and Broughton, R. S. 2005. Measurement of tensile strength of unsaturated sandy loam soil. Soil and Tillage Research, 81(1), 15-23. [doi:10.1016/j.still.2004.04.002]
Li, R. J., Zheng, W., and Wu, L. Y. 2012. A Device of Unsaturated and Saturated Soil Tensile Strength Test Based on Electric Control Loading. China Patent, CN201110052708.8.
Lu, N., Wu, B., and Tan, C. 2007. Tensile strength characteristics of unsaturated sands. Journal of Geotechnical and Geoenvironmental Engineering, 133(2), 144-154. [doi:10.1061/(ASCE)1090-0241 (2007)133:2(144)]
Lü, H. B., Zeng, Z. T., Ge, R. D., and Zhao, Y. L. 2013. Experimental study of tensile strength of swell-shrink soils. Rock and Soil Mechanics, 34(3), 615-620. (in Chinese)
Ma, X. T., Shao, S. J., Yang, C. M., and Li, X. L. 2013. Experimental research on the strength characteristic of unsaturated structural loess. Chinese Journal of Geotechnical Engineering, 35(s1), 68-75. (in Chinese)
Shao, S. J., and Deng, G. H. 2008. The strength characteristics of loess with different structures and its application in analyzing the earth pressure on loess tunnel. China Civil Engineering Journal, 41(11), 93-98. (in Chinese) [doi:10.3321/j.issn:1000-131X.2008.11.014]
Wang, J. J., Zhu, J. G., Chiu C. F., and Zhang, H. 2007. Experimental study on fracture toughness and tensile strength of a clay. Engineering Geology, 94(1-2), 65-75. [doi:10.1016/j.enggeo.2007.06.005]
Yao, Y. P., Lu, D. C., Zhou, A. N., and Zou, B. 2004. General nonlinear strength theory and its transformation stress space. Science in China (Series E: Technological Sciences), 34(11), 1283-1299. (in Chinese) [doi:10.3969/j.issn.1674-7259.2004.11.009]
Zhang, Y., Zhang, B. Y., Sun, X., and Li, G. X. 2010. Experimental study on triaxial tensile property of compacted clay. Journal of Hydroelectric Engineering, 29(6), 172-177. (in Chinese)
Zhou, M. L., and Hou, W. 2012. Experiment study of tensile strength characteristics of chlorine saline soil. Journal of Zhengzhou University of Light Industry (Natural Science), 27(4), 21-25. (in Chinese) [doi:10.3969/j.issn.1004-1478.2012.04.006]

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