Experimental investigation of non-destructive evaluation of watercontent related shrinkage of cohesive soils with different mineralogy via 3d-laserscanning (LaserShrink)

• Applicant: Professor Dr.-Ing. Sascha Henke
• Subject Area: Geotechnics, Hydraulic Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 558972480

Soil is a multiphase material which means that the grain structure is formed of the solid phase and a pore system typically filled with pore water and/or pore air. Especially due to changes in climatic or climateinfluenced boundary conditions (temperature, water-loss due to rootsystem etc.) the water content in the surface-near subsoil areas changes continuously. This leads to shrinkage and/or swelling. Especially regarding the climate change and increasing temperatures in many regions the problem of soil-shrinkage induced settlements is continuously increasing. Regarding the system soil-climate-structure different factors influence the water content of the subsoil. Due to dewatering caused by high temperatures in context with low amounts of rainfall together with dewatering by roots a significant reduction in pore water leads to water movement in direction towards the soil subsurface. This leads to suction stresses inside the soil matrix causing shrinkage of the soil leading to settlements of adjacent buildings for example. The current research project will asses this topic in detail. By means of experimental investigations the following research topics are to be investigated: - Development and verification of a method for realistic and entire prediction of the soil-shrinkage-characteristic-curve (SSCC) for clayey soils using 3D-laserscanning technique. - Investigation of the influence of sample geometry in laboratory tests on the SSCC and deduction of the optimum sample geometry for prognosis of overall and regular volumetric shrinkage depending on water content. - Systematic evaluation of SSCC of clayey soils with respect to different climatic boundary conditions as well as mineralogy, - Investigation of hysteresis-effects on the SSCC of clayey soils, - Deduction of semi-empirical prognosis models for estimation of the SSCC with respect to the above mentioned parameters.

• DFG Programme: Research Grants