| Abstract |
The measurements of fundamental variables in granular materials in motion exhibits important limitations because the sensors are only able to give local measurements and they do not work properly in motion.
The scaled laboratory tests (including centrifuge tests) are a fundamental way to evaluate the behavior of materials, the definition and validation of constitutive models and the calibration of parameters. Unfortunately, the scaled laboratory tests, with a relative high cost, only provide a reduced number of quantified data due to the limitation of the sensors.
This project presents an innovative methodology for massive and non-destructive mining of information in laboratory tests carried out on granular materials by means of the analysis of images of different length waves (visible range and infrared) and their interpretation.
The procedure will allow the digitalization of the motion (position, velocity and acceleration), the water content, in the case of non-saturated granular soils, and the temperature in the whole domain associated with particles or portions of granular material in motion. A numerical code transforming the data available in the image to the measured variables will be developed and offered as open source.
The proposal falls within in the field of Geotechnical Engineering and, in particular, in the study of rainfall induced landslides. The analysis of landslide is a very active research line in the field of Civil Engineering. The cost due to the human losses and the economic impact is very significant and one of the main problems associated with natural risk.
Recent research lines on landslides focus on the post-failure behavior, a fundamental aspect to quantify the risk and to define mitigation measurements. Nowadays, there are important limitations in the definition of models to reproduce the complex rheological behavior of granular materials subjected to different ranges of strains and their validation by means of laboratory tests is required.
Another important aspect recently highlighted in the analysis of landslides is the effect of the heat dissipation during motion and the localized temperature increments in the shear bands. The heat becomes a determinant factor controlling the landslide velocity and as a triggering factor of rapid landslides with catastrophic consequences. Therefore, it is necessary to evaluate the landslides taking into account the temperature as a fundamental variable.
The validation of the ideas behind of this project will be carried out by means scaled laboratory tests of landslides with humidity control. However, the methodology and software developed in this project will be valid in other applications that handle granular material. These potential fields will be explored once the idea is fully developed. |