Formation of Clay-Rich Layers at The Slip Surface of Slope Instabilities: The Role of Groundwater

Abstract

Some landslides around the world that have low-angle failure planes show exceptionally poor mechanical properties. In some cases, an extraordinarily pure clay layer has been detected on the rupture surface. In this work, a complex landslide, the so-called Diezma landslide, is investigated in a low- to moderate-relief region of Southeast Spain. In this landslide, movement was concentrated on several surfaces that developed on a centimeter-thick layer of smectite (montmorillonite-beidellite) clay-rich level. Since these clayey levels have a very low permeability, high plasticity, and low friction angle, they control the stability of the entire slide mass. Specifically, the triggering factor of this landslide seems to be linked to the infiltration of water from a karstic aquifer located in the head area. The circulation of water through old failure planes could have promoted the active hydrolysis of marly soils to produce new smectite clay minerals. Here, by using geophysical, mineralogical, and geochemical modelling methods, we reveal that the formation and dissolution of carbonates, sulfates, and clay minerals in the Diezma landslide could explain the elevated concentrations of highly plastic secondary clays in its slip surface. This study may help in the understanding of landslides that show secondary clay layers coinciding to their low-angle failure planes.

Rainfall-Induced or Lake-Water-Level-Controlled Landslide? An Example from the Steep Slopes of Lake Balaton, Hungary

“…Our aim is to analyze the effects of rainfall and lake-level changes on the occurrence of landslides and surface movements. A number of studies have also been carried out in recent years on the effect of different water patterns on slope stability [53][54][55][56][57][58][59][60].…”

Nanoarchitectonics of Illite-Based Materials: Effect of Metal Oxides Intercalation on the Mechanical Properties

“…The evolution of clay minerals in geological history inevitably interacts with iron and aluminum oxides [ 4 , 5 ], playing a decisive role in the strength and stability of geotechnical engineering. Many geological disasters, such as landslides [ 6 , 7 , 8 ], foundation instability [ 9 , 10 ], and drilling collapse [ 11 , 12 ], are closely related to clay minerals. Recently, clay minerals are extensively used in modern industry as a necessary industrial raw material [ 13 , 14 ], and the hydration, adsorption, and swelling along with the thermodynamic properties of clay minerals have become research hotspots in the fields of environment and chemical engineering.…”

Bridging Structure, Dynamics, and Thermodynamics: An Example Study on Aqueous Potassium Halides

“…The interactions between water and ions play a vital role in life across multiple length scales. − At the molecular level, the delicate interplay between ion–water interactions and ion–biomolecule interactions results in perturbations to biomolecular stability fundamental to life as we know it. − At the mesoscale, ion–water interactions play a key role in the manufacturing of food, textiles, and the mining industry . Finally, at the macroscale, understanding the ion–water interactions present in clays can help us to understand and prepare for environmental processes such as mudslides and also understand the properties of recently discovered extraterrestrial bodies of liquid water. − …”

“…6−9 At the mesoscale, ion−water interactions play a key role in the manufacturing of food, 10 textiles, 11 and the mining industry. 12 Finally, at the macroscale, understanding the ion−water interactions present in clays can help us to understand and prepare for environmental processes such as mudslides 13 and also understand the properties of recently discovered extraterrestrial bodies of liquid water. 14−17 An important and long-standing question that applies to all of these fields concerns the distance over which ions perturb water structure and dynamics.…”