The Creep-Damage Model of Salt Rock Based on Fractional Derivative

Hongwei Zhou,Dongjie Xue,Di Liu,Yang Zhao,Gang Lei

doi:10.3390/en11092349

Hongwei Zhou, Dongjie Xue + Show 3 more

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https://doi.org/10.3390/en11092349

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Abstract

The use of salt rock for underground radioactive waste disposal facilities requires a comprehensive analysis of the creep-damage process in salt rock. A computer-controlled creep setup was employed to carry out a creep test of salt rock that lasted as long as 359 days under a constant uniaxial stress. The acoustic emission (AE) space-time evolution and energy-releasing characteristics during the creep test were studied in the meantime. A new creep-damage model is proposed on the basis of a fractional derivative by combining the AE statistical regularity. It indicates that the AE data in the non-decay creep process of salt rock can be divided into three stages. Furthermore, the authors propose a new creep-damage model of salt rock based on a fractional derivative. The parameters in the model were determined by the Quasi-Newton method. The fitting analysis suggests that the new creep-damage model provides a precise description of full creep regions in salt rock.

Highlights

Salt rock is widely used in energy storage and radioactive waste disposal in underground engineering facilities
The full creep regions of salt rock can be divided into three stages: The transient creep region, the steady-state creep region, and the accelerated creep region [6]
The results indicated that the three-element model provided a precise description of creep deformation [7]

Summary

Introduction

Salt rock is widely used in energy storage and radioactive waste disposal in underground engineering facilities. Research on the creep-damage of salt rock is significant to avoid the loss of effective storage space in underground cavities. The full creep regions of salt rock can be divided into three stages: The transient creep region (the primary region), the steady-state creep region (the secondary region), and the accelerated creep region (the tertiary region) [6]. Many efforts have been expanded on analyzing creep-damage features through mathematical modeling. Passaris has studied the creep of salt rock by using a three element model. The results indicated that the three-element model provided a precise description of creep deformation [7]. Ghavidel performed axial creep experiments of salt rock under different temperatures

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