Fundamental Theroy and Experimental Research

Normalized stress-strain behavior of silty sand under freeze-thaw cycles

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  • 1. School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China; 2. Transportation Industry Laboratory of Highway Construction and Maintenance Technology in Permafrost Regions-Qinghai Research Observation Base, Qinghai Research Institute of Transportation, Xining, Qinghai 810000, China

Received date: 2014-05-13

  Online published: 2018-06-14

Supported by

Project supported by the National Program on Key Basic Research Project of China (973 Program) (Grant No. 2012CB026104) and National Natural Science Foundation of China (Grant Nos. 51378057 and 41371081)。

Abstract

The unconsolidated undrained triaxial shear tests are carried out to explore the stress-strain relationship behaviors of unfrozen silty sand under different freeze-thaw cycles. Based on the test results, when the confining pressure is low, both the unfrozen silty sand or the silty sand experiencing fewer freeze-thaw cycles exhibits weak strain softening phenomenon; And stain of silty sand will change from weak stain softening to stain hardening after experiencing a certain number of freeze-thaw cycles. No matter the unfrozen silty or the frozen silty shows strain hardening under a higher confining pressure level, their stress-strain curves are both the typical hyperbola. and the normalization of the stress-strain relationship is vital to study the stress-strain properties. In this paper, four kinds of common normalization factors, which are widely adopted for unfrozen soil to study stress-strain characteristics as well as the corresponding normalized conditions, are introduced. Based on the normalization factors above, a new normalized factor is proposed to analyze the stress-strain relation of soils under freeze-thaw cycles and the normalized conditions are defined. A new normalized stress-strain equation is established to predict the stress-strain curve of silty sand under freeze-thaw cycles and confining pressures. Comparison of the prediction and test results shows that the established predict model can consider the influences of freeze-thaw cycles and has better fitting and prediction accuracy.

Cite this article

CHANG Dan , LIU Jian-kun , LI Xu , . Normalized stress-strain behavior of silty sand under freeze-thaw cycles[J]. Rock and Soil Mechanics, 2015 , 36(12) : 3500 -3505 . DOI: 10.16285/j.rsm.2015.12.021

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