Experimental investigation of the creep behaviour of remoulded loess under different levels of compactness

PLoS One. 2022 Jan 24;17(1):e0262456. doi: 10.1371/journal.pone.0262456. eCollection 2022.

Abstract

Generally, a loess high fill project will undergo a time-dependent deformation and settlement process for a long time after the initial fill. Understanding the creeping behaviour of compacted loess is an important part of determining the stability of a compacted loess foundation. To study the creep behaviour of remoulded loess under different levels of compactness, we performed triaxial shear and triaxial creep tests using Q2 loess specimens obtained from the new district of Yan'an city. Based on laboratory test results, the triaxial shear and creep characteristics of remoulded loess under different levels compactness are summarised. The regularity of instantaneous strain, creep strain, total accumulated strain and initial shear modulus were analysed and the relationship between the compactness and long-term strength of remoulded loess is provided. It was found that the remoulded loess becomes harder and its long-term strength increases with an increase in compactness. Furthermore, we propose a new creep model (HD), based on the hardening-damage mechanism, and have derived one-dimensional (1D) and three-dimensional (3D) creep equations based on this new creep model. This new creep model is flexible enough to fit the typical creep test curves of remoulded loess, while perfectly describing the tertiary creep stage. Finally, the sensitivity of the HD creep model parameters was analysed; the results indicate that the parameters denoted as α, γ, and β significantly affect the morphological changes and various stage characteristics are represented by the creep curve.

Publication types

  • Research Support, Non-U.S. Gov't

Grants and funding

This work is supported by the National Natural Science Foundation of China (41790442, 41602305), and the foud had role in study design, data collection, decision to publish.