Implications of sulfur mineralogy and consequences of pyrite oxidation for ground engineering

Abstract

Aggressive ground conditions and physical deterioration of ground and engineering materials are attributed to a wide range of factors but in the UK a high proportion of occurrences in the engineering environment result from the presence of sulfur minerals, particularly pyrite which is unstable in oxidising and damp atmospheric weathering conditions. The oxidation reactions are complex in that the rate - and the products - depend on the crystalline form and grain size of the pyrite as well as the host mineralogy, rock fabric and environmental conditions, including exposure to weathering action brought about by engineering works. Therefore, to prevent any negative impacts on engineering design and construction, the possibility of changes in the potential for pyrite oxidation during and after construction need to be considered. The aim of this paper is to review the implications of sulfur minerals, especially of pyrite oxidation, with reference to engineering situations in which pyrite oxidation may have a significant negative impact. Changes in the potential for oxidation because of ground engineering works and strategies for avoiding problems are also considered. Thematic collection: This article is part of the Sulfur in the Earth system collection available at: https://www.lyellcollection.org/topic/collections/sulfur-in-the-earth-system