Creep of calcareous sand in Tunisia: effect of particle breakage at low stress level

Hyunwook Choo,Young-Hoon Jung,Lamia Touiti,Minhyuk Kwon

doi:10.1186/s40703-020-00123-2

Hyunwook Choo, Young-Hoon Jung + Show 2 more

Open Access

https://doi.org/10.1186/s40703-020-00123-2

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Abstract

Aims/hypothesisOne of the critical mechanisms determining creep in granular materials is the breakage of soil particles. This study aims at evaluating the time-dependent creep deformation of calcareous sand at low effective stress conditions.MethodsK0 creep tests were performed for both calcareous and silica sands at low stresses of 65 and 120 kPa, and the results of creep tests were compared with the results of constant rate of strain (CRS) tests at high stress levels up to 12 MPa. For a quantitative evaluation of the effect of the particle breakage on the creep deformation of calcareous sand, the relative breakage (B_{r}) was determined based on the results of sieve analyses.ResultsThe results demonstrate that Tunisia calcareous sand experiences significant particle breakage during creep and the consequent creep deformation at low stress level. The determined B_{r} after creep at low stress level is comparable with that after the CRS test at high stress level.ConclusionsHigh potential of particle breakage inherited by characteristic minerology of the calcareous Tunisia sand significantly influences the creep deformation at low stress level.

Highlights

Creep phenomenon, which is the continuous deformation of soils under constant effective stress condition, greatly affects the engineering behaviors of soils, including the long-term ground settlement; the creep in fine-grained soils has been the research topic of many previous studies [1]
This study aims at investigating time-dependent creep deformation of calcareous sand at low effective stress conditions
To understand this irregularity from a mechanical viewpoint, it is worth noticing Ter-Stepanian [11] who described a stochastic nature for the creep deformation of which the rate is not necessarily uniform owing to the particulate nature of soils governed by forces at randomly oriented interparticle contacts

Summary

Introduction

Creep phenomenon, which is the continuous deformation of soils under constant effective stress condition, greatly affects the engineering behaviors of soils, including the long-term ground settlement; the creep in fine-grained soils has been the research topic of many previous studies [1]. One possible mechanism determining creep in coarse-grained soils (e.g., sand) is the breakage of soil particles under heavily loaded conditions (> 1 MPa) [3, 5, 6]. In the case of calcareous sand, the particle breakage can initiate at relatively low effective stress condition because of its characteristic mineralogy. This study aims at investigating time-dependent creep deformation of calcareous sand at low effective stress conditions. To link the creep behavior of calcareous sand with the particle breakage, one-dimensional K0 compression test was performed first, and the sieve analysis was followed

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Conclusion