Public defence in Building Technology, M. Sc. Masoud Torkan

Title of the thesis: Photogrammetry for characterizing rock fracture roughness, physical aperture, and hydromechanical propertiers

Doctoral student: Masoud Torkan
Opponent: Prof. Fredrik Johansson, KTH Royal Institute of Technology, Sweden
Custos: Prof. Mikael Rinne, Aalto University School of Engineering, Department of Civil Engineering

Photogrammetry for measurement in rock mechanics

Rock mass stability and permeability are highly influenced by rock fractures. Precise analysis is crucial in rock mechanics applications, such as tunnels, mines, nuclear waste repositories, and geothermal systems. Accurate measurement of the geometrical and hydromechanical properties of fractures is vital for understanding fracture behavior under different conditions. Geometrical properties, like roughness and physical aperture, control the shear and hydromechanical behavior of a fracture. Photogrammetry is a powerful and accurate tool for reconstructing a 3D model that can be used to measure the geometrical properties of rock fractures. The purpose of the research was to develop a high-precision photogrammetric method capable of measuring geometrical properties on different scales. The main results included the development of this high-precision photogrammetric method with the optimal number of scale bars. Furthermore, the scale effect on shear strength and hydromechanical properties was investigated using different sample sizes (2 m x 1 m and 1 m x 1 m). The photogrammetric 3D models were used to simulate fluid flow through fractures and were validated with experimental results that showed good agreement. The new high-precision photogrammetric method, along with the optimal number of scale bars, deepen our understanding of fracture behavior. This understanding can be applied in the rock mechanics field to improve the design and safety of infrastructures in rock mass.

Key words: photogrammetry, fracture, roughness, physical aperture, camera, fluid flow, accuracy, scale effect

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/

Contact information: Masoud Torkan, [email protected], tel.: +358504009520

Doctoral theses of the School of Engineering: https://aaltodoc.aalto.fi/handle/123456789/49