A review of the identification methods and types of collapsible soils

Abstract

Collapsible soils have caused infrastructural damages resulting in several economic losses and loss of lives in certain cases. The prerequisite for collapse occurring is an open metastable structure; capable of developing in any soil type given the right placement or aging conditions. Natural and anthropogenic (engineered and non-engineered) collapsible soils exist in many regions of the world. In their unsaturated state, these soils exhibit high enough shear strength and stiffness (provided by inter-particle bonds of either suction, clay, calcium carbonate, or other salts) but upon wetting and/or loading they undergo repacking due to bond softening/weakening. This collapse of the soil structure leads to a rapid volume decrease and consequently associated issues such as rapid differential settlement, ground fissuring and landslides occur causing damages to civil structures, and loss of lives. Despite these threats and the large body of research available in this subject, there is still poor understanding of the process of softening/weakening and the collapse mechanism of certain bond in some collapse elements. The aim of this paper is to provide a state-of-the-art comprehensive review of the different types of collapsible soils, field, and laboratory methods of predicting and measuring their potential to collapse. This understanding is crucial for geotechnical characterisation of soils in order to design safe and economic infrastructures with their long-term serviceability also in focus.

Utilização do sistema de informação geográfica para identificar solos colapsíveis na região do semiárido brasileiro

“…Por fim, sob a tensão de inundação de 200 kPa, a Figura 3c apresenta o cenário resultante, seguindo o critério de Jennings & Knigth (1975), quando foram constatados 37,31% dos registros classificados como problemáticos, 31,34% como problemas moderados, 26,87% como problemas graves e 4,48% como sem problemas (Silva, 2022). As principais características geotécnicas dos solos colapsíveis e dos locais de ocorrência são solos não saturados; os grãos estão ligados por vínculos de argilas, óxidos de ferro, alumínio e carbonatos, formando uma estrutura metaestável; são de origem recente e ocorrem em regiões onde a taxa de evapotranspiração é sempre maior do que a de precipitação; ocorrem também em regiões tropicais em que há lixiviação dos finos nos horizontes mais superficiais e onde alternam estações de seca e chuvas concentradas em curto período de tempo (Clemence & Finbarr, 1981;Ferreira, 1995;Mendonça Neto & Ferreira, 2015;Vilar & Ferreira, 2015;Li, Vanapalli & Li, 2016;Opukumo et al, 2022).…”

“…Solos colapsíveis são encontrados em muitas partes do mundo, Estados Unidos da América, Brasil, Argentina, Uruguai, Espanha, Austrália, Kuwait, Egito, Irã, Sul África e China, particularmente em áreas áridas e semiáridas dessas regiões (Dudley, 1970). A maioria das ocorrências em solo naturais colapsíveis são areias em depositados eólicos (Aitchison, 1973;Jennings & Knigth, 1975;Clemence & Finbarr, 1981;Ferreira, 1995;Rafie, Moayed, & Esmaeli, 2008;Ayadat & Hanna, 2012;Mahmood & Abrahim, 2021;Opukumo et al, 2022).…”

Studying the mechanical behavior of loess-cement mixtures and adopting a cement-soil cushion (CSC) as a shallow ground improvement solution for foundations laying on collapsible soils

“…These soils can manifest naturally (loess soil) or result from anthropogenic activities. Collapse is thought to occur when the bond between the particles is destroyed by wetting with or without additional loading, thereby rendering the original open structure dense (Opukumo et al, 2022). To effectively manage and mitigate the challenges posed by collapsible soils, it is essential to first identify their presence.…”

A comprehensive study on soil parameters influencing collapsibility of loess through data analysis

“…Additionally, in the past few years, several research have been focused on developing equations to predict the CP of soils. Some of these equations are derived from the results of the limited number of oedometer tests conducted on samples collected from a limited geographical region (Opukumo et al, 2022). A number of models are based on numerical analysis (M. Jiang et al, 2017;M.…”