Daniel Johansson
Daniel Johansson

Daniel Johansson

Associate Professor
Luleå University of Technology
Mining and Geotechnical Engineering
Department of Civil, Environmental and Natural Resources Engineering
Daniel.Johansson@ltu.se
+46 (0)920 492361
F610B Luleå

Background

2011 PhD in Rock Engineering and Rock Mechanics. Supervisor Prof. Finn Ouchterlony

Thesis: Effects of confinement and initiation delay on fragmentation and waste rock compaction - Results from small-scale tests.

2008 Licentiate Degree in Rock Engineering and Rock Mechanics. Supervisor Prof. Finn Ouchterlony

Thesis: Fragmentation and waste rock compaction in small-scale confined blasting

2003 MSc in Civil Engineering. Specializing in Rock Engineering

Current research areas

Development of a methodology to measure the curvature of the detonation front in the civil explosives in field.

Improved understanding of the detonation properties of non-ideal explosive is needed. Today, it is possible to measure with high speed cameras the curvature of a detonation front in lab-scale. Though, to Improve the understanding and link the detonation properties to the actual rock a new measurement technique has to be developed. During spring 2016, I will with my Colleagues design and evaluate new methods Regarding this matter. Trials are planned to be tested in lab scale, where confined charges (mortar cylinder) with Varying diameters and emulsion explosives.

 

Investigate the work capacity of a civilian explosive, especiallywhen explosive ice interacted with the rock ie coupled charges.

There is a scientific need to understand and measure the actual partitioning of energy from the chemically stored energy into explosives to the detonation and how the energy is Transmitted to the surrounding rock. Understanding this, Could Potentially improvement the breakage of the rock and futures criteria of explosives.

 

The initial plan is to work with numerical modeling During 2016 and During 2017, field tests will be Carried out and the design will be based upon the numerical results.

 

The use of shockwave Interactions in rock blasting

This is a part of the energy partitioning, where more Efforts Could be Made to distinguish and understand the effects of shock waves in rock fragmentation. Fundamental Research on dynamic fracture mechanics havebeen applied EARLIER, but still I do see gaps of understanding the complex / 3D volumes and the influence of shock waves on the fragmentation.

 

Improved breakage and design of sub-level caving blasts; field tests and numerical modeling

Complex designs as for sub-level caving involves multiple technical and scientific challenges. It involves confined blasting, gravity flow and Varying explosives charge distribution. During 2016-2017 it is planned to carry out bothering half-scale and full-scale experiments to Improve the understanding of the dynamics of confined blasting, gravity flow and the breakage characteristics of the blast. In combination of this, detailed numerical modeling of Both SLC blasts and gravity flow is planned to be Carried out.

 

Toxic fumes from blasting

To Improve the knowledge of production of toxic fumes from the detonation of commercial explosives in rock blasting bothering for surface mining and underground mining. It is Currently the carried out and planned for Further Research During 2016, it will in detail quantify the toxic fumes from common types of emulsion explosive and Will be Carried out bothering in controlled conditions as set Swebrec-LTU blasting chamber and in field (under production conditions )

Blast optimization for mining e understand and characterize blast effects on downstream operations

Focus to link characterization tools and process control techniques to all points along the mining process, to allow them to RESPOND and controlling changes in the in-situ rock mass characteristics. The approach is to understand the blasting operation, later to Optimise IT Against the Demands in to FollowingHistory processes as for example loading / mucking, gravity flow and energy consumption.

Investigate the effect of geological properties on blast damage on the surrounding rock

Current blast damage tables do not take into Consideration the geology as for example the rock type and the presence of natural cracks. There is a need to analyze this and Further Improve the definition and effects of blast damage. The planned research is to analyze the effects of the geological properties on the blasting damage by using Measured While Drilling Data Gathered During Conventional tunnel drilling as an Descriptor of the rock mass. From there, the hypothesis Is that we can with field evaluations / measurements describe the damage level logger with data drilling and core analysis.

Earlier research

The focus areas since Mainly doctorate have been full-scale blasting, Experimental Design and numerical modeling.

Publications

Article in journal

Multivariate evaluation of blast damage from emulsion explosives in tunnels excavated in crystalline rock (2019)

Ittner. H, Olsson. M, Johansson. D, Schunnesson. H
Tunnelling and Underground Space Technology, ISSN: 0886-7798, Vol. 85, s. 331-339
Conference paper

Calibration and Validation of Reactive Flow Model Parameters for an emulsion explosive (2018)

Yi. C, Nyberg. U, Johansson. D
Paper presented at : 12th International Symposium on Rock Fragmentation by Blasting, Fragblast 12, Luleå, Sweden on June 9-15
Article in journal

Compaction of confining materials in pillar blast tests (2018)

Petropoulos. N, Wimmer. M, Johansson. D, Nordlund. E
Rock Mechanics and Rock Engineering, ISSN: 0723-2632, Vol. 51, nr. 6, s. 1907-1919
Article in journal

Effects of in-situ stresses on the fracturing of rock by blasting (2018)

Yi. C, Johansson. D, Greberg. J
Computers and geotechnics, ISSN: 0266-352X, Vol. 104, s. 321-330
Conference paper

Numerical investigation for timing effects on fragmentation based on a coupled FEM-BPM-PBM model (2018)

Yi. C, Johansson. D, Nyberg. U
Paper presented at : 12th International Symposium on Rock Fragmentation by Blasting, Fragblast 12, Luleå, Sweden on June 9-15, 2018