Tracking Deformation Processes at the Legnica Glogow Copper District (Poland) by Satellite InSAR—II: Żelazny Most Tailings Dam

Paolo Mazzanti,Alessandra Sciortino,Benedetta Antonielli,Stefano Scancella,Francesca Bozzano

doi:10.3390/land10060654

Paolo Mazzanti, Alessandra Sciortino + Show 3 more

Open Access

https://doi.org/10.3390/land10060654

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Journal: Land	Publication Date: Jun 18, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: Sapienza University of Rome, University of L'Aquila

Abstract

The failures of tailings dams have a major negative impact on the economy, surrounding properties, and people’s lives, and therefore the monitoring of these facilities is crucial to mitigate the risk of failure, but this can be challenging due to their size and inaccessibility. In this work, the deformation processes at Żelazny Most tailings dam (Poland) were analyzed using satellite Ad-vanced Differential SAR Interferometry (A-DInSAR) from October 2014 to April 2019, showing that the dam is affected by both settlements (with a maximum rate of 30 mm/yr), and horizontal sliding in radial direction with respect to the ponds. The load of the tailings is pushing the dam forward along the glacio-tectonic shear planes located at depth, in the Pliocene clays, causing horizontal displacements at a rate up to 30 mm/yr, which could lead to a passive failure of the dam. The measured displacements have been compared with the ones observed by in situ data from the 90s to 2013, available in the literature. The outcomes indicate that intense localized deformations occur in the eastern and northern sectors of the dam, while the western sector is deforming evenly. Moreover, although the horizontal deformation had a slowdown from 2010 until 2013, it continued in 2014 to 2019 with recovered intensity. The upper and the recent embankments are affected by major settlements, possibly due to a lower consolidation degree of the most recent tailings and a larger thickness of compressible materials.

Highlights

Introduction published maps and institutional affilTailings dams are earth dams without an impermeable core, designed for permanent containment of mineral waste
This method is the most cost-effective [1,2], as it consists in the construction of a foundation base very resistant to load and of the so-called starter dam, the tailings are discharged into the basin until it is saturated and the placing of the new material occurs within the existing impoundment, that is, the new embankments are founded on tailings [3,4]
This paper focuses on the deformation phenomena that affect the tailings dam of Żelazny Most (Figure 1) using satellite A-DInSAR

Summary

Introduction

Introduction published maps and institutional affilTailings dams are earth dams without an impermeable core, designed for permanent containment of mineral waste. This method is the most cost-effective [1,2], as it consists in the construction of a foundation base very resistant to load and of the so-called starter dam, the tailings are discharged into the basin until it is saturated and the placing of the new material occurs within the existing impoundment, that is, the new embankments are founded on tailings [3,4] These latter ones consist of solid or liquid waste represented by a mixture of fine particles, in some cases toxic or radioactive, deriving from mechanical separation processes of the mineral of economic interest from the gangue.

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