EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Influence of temperature on the hydrothermal clay soils' shear strength of the Nizhne-Koshelevsky and Verkhne-Pauzhetsky thermal fields.

Ruslan Kuznetsov1, Mikhail Chernov2, Victoria Krupskaya3, and Ruslan Khamidov2
Ruslan Kuznetsov et al.
  • 1Institute of Volcanology and Seismology, Far-Eastern Branch of Russian Academy of Sciences, Petropavlovsk-Kamchatskiy, Russian Federation (
  • 2Faculty of Geology, Moscow State University, Moscow, Russian Federation (
  • 3Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences, Moscow, Russian Federation (

Nizhne-Koshelevskoe and Verkhne-Pauzhetskoe thermal fields are located in the south of Kamchatka, the first - within the Koshelevsky volcanic massif, the second - on the territory of the Pauzhetsky geothermal field. The first horizon from the surface in these fields is formed by clayey soils, that have been formed as a result of hydrothermal alteration of volcanic rocks. And in the natural conditions clayey soils are at temperatures reaching 100 °C.

Samples of undisturbed clay soils were taken within the thermal fields. The samples are characterized by a density of 1.29 - 1.42 g/cm3, rather high values of the weight moisture (90-110%), and temperatures of 50 - 70 °C.

The samples are dominated by clay minerals: kaolinite and mixed-layer - kaolinite-smectite, their content is about 75%. The other 25% are microcline, cristobalite, anatase, gypsum, pyrite, marcasite, quartz and alunite.

For samples of undisturbed clay soils, direct shear tests were carried out at a temperature of 20 °C and at a temperatures of the samples close to their natural temperatures (50–70 °C). Thus, the values of cohesion and the angle of internal friction of the samples were determined.

The obtained results can be interfered as follows: as a result of an increase in the temperature of clayey soils, the thickness of electric double layer on the surface of clay particles decreases. On the one hand, it leads to a decrease of cohesion value between the clay particles and the beginning of shear deformations at lower vertical loads. On the other hand, a smaller thickness of electric double layer brings particles closer to each other, which is the reason for an increasing angle of internal friction and shear resistance at higher vertical loads.

How to cite: Kuznetsov, R., Chernov, M., Krupskaya, V., and Khamidov, R.: Influence of temperature on the hydrothermal clay soils' shear strength of the Nizhne-Koshelevsky and Verkhne-Pauzhetsky thermal fields., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6901,, 2021.