Book Chapters

1. Bobet, A., Arson, C.F., Elsworth, D., Nelson, P., Tomac, I., Modiriasari, A. (2019). “The role of rock mechanics in the 21st Century.” (2019). Chapter 11 in Geotechnical Fundamentals for Addressing New World Challenges. N. Lu and J.K. Mitchell, Eds. Springer. 1-41. ISBN: 978-3-030-06249-1.

Technical Journal Publications

2. Tomac, I. and Gutierrez, M. Discrete element modeling of non-linear submerged particle collisions. Granular Matter, Volume 15, p. 759-769 (2013).
3. Tomac, I., Gutierrez, M. Fluid lubrication effects on particle flow in a channel. International Journal of Multiphase Flow. Volume 65, p. 143-156 (2014).
4. Tomac, I., Gutierrez, M. Micromechanics of proppant agglomeration during settling in hydraulic fractures. Journal of Petroleum Exploration and Production Technology, p. 1-18 (2015).
5. Tomac, I., Gutierrez, M. Formulation and implementation of coupled forced heat convection and heat conduction in DEM. Acta Geotechnica. Volume 10, p. 421-433 (2015).
6. McCartney, J.S., Sánchez, M., and Tomac, I. Energy geotechnics: Advances in subsurface energy recovery, storage, and exchange. Computers and Geotechnics. Volume 75, p. 244-256. (2016)
7. Tomac, I., M. Gutierrez. Coupled hydro-thermo- mechanical modeling of hydraulic fracturing in quasi-brittle rocks using DEM. Journal of Rock Mechanics and Geotechnical Engineering. Volume 9, Issue 1, p. 92-104 (2017).
8. Caulk R., Tomac, I. Reuse of abandoned oil and gas wells for geothermal energy production. Renewable Energy. Volume 112, Issue C, p. 388-397 (2017).
9. Luo L., Tomac, I. Experimental investigation of particle agglomeration effects on slurry settling in Viscous Fluid. Transport in Porous Media. 121, p. 333-352 (2018).
10. Tomac, I., Sauter, M.A Review on challenges in the assessment of geomechanical rock performance for deep geothermal reservoir development. Renewable and Sustainable Energy Reviews. Volume 82, Part 2, p. 3972-3980. (2018).
11. Luo L., Tomac, I. Particle Image Velocimetry (PIV) Analysis of Particle Settling in Narrow Fracture Experiments. Geotechnical Testing Journal. Volume 41, Issue 2. (2018).
12. Fjaestad, D., Tomac, I. E Experimental investigation of sand proppant particles flow and transport regimes through narrow slots. Powder Technology. Volume 343, p. 495 -511. (2019).
13. Tomac, I., Gutierrez, M. Micro-mechanics of hydro-thermo-mechanical processes during convective heat flow from a borehole in rock. Journal of Engineering Mechanics. 45 (8), 04019055. (2019). 
14. Tomac, I., Gutierrez, M. Micromechanics of Hydraulic Fracturing and Damage in Rock Based on DEM Modeling. Granular Matter. 22:56 (2020).

Technical Conference Publications and Abstracts

1. Movasat, M. and Tomac, I. Post-fire Mudflow Prevention by Biopolymer Treatment of Water Repellent Slopes. GeoCongress, Minneapolis, MI, USA. (2020).
2. Tomac, I. and Yamashiro, B. Micromechanics of dense-phase sand-fluid flow and transport in fractures. XVI Panamerican Conference on Soil Mechanics and Geotechnical Engineering, Cancun, Mexico (2019). 
3. Yamashiro, B. and Tomac, I. Proppant Transport Behavior due to Varying Fracture Geometry and Particle Concentration Distribution. EMI/G-I, Pasadena, CA, USA (2019). 
4. Yamashiro, B. and Tomac, I. Proppant Transport Behavior in Varying Fracture Alignments. 53rd ARMA 53rd US Rock Mechanics/Geomechanics Symposium, New York City, USA, 2019. (2019). 
5. Yamashiro, B. and Tomac, I. Particle-Fluid Flow and Transport Between Geometrically Rough Surface Boundaries. DEM 8, Twente, Netherlands. (2019). 
6. Tomac, I., Fjaestad, D. and Luo L. Experimental and Numerical Investigation of Micro-Mechanics of Particle-Fluid Flow and Transport. IS-Atlanta 2018: Geo-Mechanics from Micro to Macro, Atlanta, GA, USA. (2018).
7. Fjaestad, D., Tomac, I. Proppant Flow and Transport in a Narrow Fracture in Turbulent Flow Regime, International Symposium on Energy Geotechnics (SEG-2018), EPFL Lausanne, Switzerland. (2018).
8. Fjaestad, D., Tomac, I. Experimental Investigation of Proppant Flow and Transport in Narrow Fractures, ARMA 2018, Seattle, CA, USA. (2018).
9. Tomac, I., Tartakovsky D. Experimental Evaluation of Turbulent Flow and Proppant Transport in a Narrow Fracture, 43rd Workshop on Geothermal Reservoir Engineering Stanford University, CA, USA. (2018).
10. Caulk, R.A., Tomac, I. Micro-mechanics of hydro-mechanical coupled processes during hydraulic fracturing in sandstone. AGU Fall Meeting, New Orleans, USA. (2017).
11. Caulk, R., Tomac, I. Reuse of abandoned oil and gas wells for geothermal energy production. AGU Fall Meeting, San Francisco, CA, USA. (2016).
12. Tomac, I., Gutierrez, M. Quantification of transient heat flow and damage around the borehole using conductive-convective heat flow and transport DEM model in synthetic rock. Proceedings of the 4th Itasca Symposium on Applied Numerical Modeling, Lima, Peru. p. 559-569 (2016).
13. Tomac, I. Hydro-thermo-mechanical behavior of granular material near the wellbore. Geo-Chicago 2016: Geotechnics for Sustainable Energy, Chicago, IL, USA. p. 22-31. (2016).
14. Luo, L., Tomac, I. Particle image velocimetry analysis of proppant settling in a narrow slot. ARMA 2016, Houston, Texas, USA. ARMA-2016-652. (2016).
15. Luo, L. and Tomac, I. Experimental study of proppant particle-particle interaction micromechanics during flow and transport in the fracture. 1st International Conference on Energy Geotechnics ICEGT 2016 in Kiel, Germany. p. 231-238. (2016).
16. Tatomir, A.B., Tomac, I., Sauter, M. A parametric sensitivity study on CO2 injection in deep saline aquifers accounting for hydro-mechanical micro fracturing. 1st International Conference on Energy Geotechnics ICEGT 2016 in Kiel, Germany. p. 223-230. (2016).
17. Tomac, I., Tatomir, A.B., Sauter, M., Effect of fracture surface damage on fluid flow and transport in geo-reservoirs. Second EAGE Workshop on Geomechanics and Energy, Celle, Germany. (2015).
18. Tomac, I., Gutierrez, M. The effect of loading rate on hydraulic fracturing in synthetic granite: A Discrete element study. 2015 AGU Fall Meeting, San Francisco, CA, USA. (2015).
19. Tomac, I., Gutierrez, M. Micromechanics of hydro-thermo-mechanical fracture propagation in granite. ARMA, Minneapolis, Minnesota, USA. (2014).
20. Tomac, I., Gutierrez, M. Coupled hydro-thermo-mechanical modeling of hydraulic fracturing in quasi-brittle rocks using DEM. IS-Cambridge, UK. (2014).
21. Tomac, I., Salkovic, A., Pest, D. Case history on determination of old bridge foundation depths using parallel seismic method. XV Danube - European Conference on Geotechnical Engineering (DECGE). (2014).
22. Tomac, I., Gutierrez, M. Particulate modeling of sand slurry flow retardation. 18th International Conference on Soil Mechanics and Geotechnical Engineering (ICSMGE), Paris, France. September. (2013).
23. Tomac, I., Gutierrez, M. Numerical study of horizontal proppant flow and transport in a narrow hydraulic fracture. 47th U.S. Rock Mechanics/Geomechanics Symposium ARMA, San Francisco, USA. June. (2013).
24. Tomac, I., Gutierrez, M. DEM study of hydraulic fracturing in enhanced geothermal systems. European Geothermal Congress, Pisa, Italy. June. (2013).
25. Tóth, A.N., McCartney, J.S., Tomac, I., Balla, L. Geothermal E-learning through Hungarian-American cooperation. European Geothermal Congress, Pisa, Italy. June. (2013).
26. Tomac, I., Gutierrez, M. DEM Study of proppant settling in a rough hydraulic fracture in granite. DEM6 International Conference, Golden, CO. August. (2013).
27. Tomac, I., Gutierrez, M. Convective-conductive heat flow in granite. DEM6 International Conference, Golden, CO. August. (2013).
28. Tomac, I, Gutierrez, M. Evaluation of the Brazilian test size effect using Discrete Element Modeling. 46th U.S. Rock Mechanics/Geomechanics Symposium ARMA, Chicago, USA. (2012).
29. Tomac, I., Čorko, D. Braced deep excavation projects in the City of Zagreb - Execution details and risk sources. 5th Meeting of the Croatian Geotechnical Society, Osijek, Croatia. (2009).
30. Marić, B., Tomac, I., Puljak, S. Lovrenćić, D. Settlement measurements in the area of the town of Sisak over a period of 30 years. 6th Austrian Geotechnik Tagung, "Vienna - Terzaghi Lecture", Vienna, Austria. (2007).
31. Tomac, I., Marić, B. Deep excavation case histories in the City of Zagreb. XIII Danube-European Conference on Geotechnical Engineering. Ljubljana, Slovenia. (2006).
32. Čorko, D., Tomac, I., Leko, I., Lašić, A. Jet-grouting application for landslide remediation. In-country training program, principles of design, rehabilitation and monitoring of landslides. Sarajevo, Bosnia and Herzegovina. (2005).
33. Tomac, I, Van Impe, W.F., Verástegui Flores, R.D., Mengé, P. Binder-soil interaction in cement deep mixing through SEM analysis. 16th ICSMGE Osaka, Japan. (2005).
34. Tomac, I., Marić, B. Foundation design of the new cable stayed bridge over the Kupa river in the town of Sisak. Book of Papers of the 1st Meeting of Croatian Bridge Constructors, Brijuni Islands, Croatia. (2005).
35. Čorko, D., Marić, B. Lovrenčić, D. Tomac, I. The application of jet-grouting method for landslide remediation. The 5th Šuklje Day, Rogaška Slatina, Slovenia. (2004).
36. Čorko, D., Marić, B. Lovrenčić, D. Tomac, I. Application of jet grouting in slide remediation. ASEP-GI Paris, France. (2004).
37. Marić, B., Kvasnička, P. Radaljac, D. Škacan, B. Tomac, I. Use of combined soil nailing and geotechnical anchor system as the retaining structure for an open excavation. 3rd Nonveiller lecture, Hvar, Croatia. (2004)
38. Tomac, I. Retaining structure for basement deepening. XIV European Young Geotechnical Engineering Conference (EYGEC), Plovdiv, Bulgaria. (2001)
39. Tomac, I. Soil nailed retaining structure for the open excavation. International Young Geotechnical Engineering Conference (IYGEC), Southampton, UK. (2000).

Research Reports

1. Gutierrez, M. Tomac, I., Kumar, D. Frash, L., and Hampton, J.C. Development and Validation of an Advanced Stimulation Prediction Model for Enhanced Geothermal Systems, Final Report to US Department of Energy, Energy Efficiency and Renewable Energy. (2014).
2. Tomac, I. Micro-mechanical Aspects of Hydraulic Fracture Propagation and Proppant Flow and Transport for Stimulation of Enhanced Geothermal Systems - a Discrete Element Study. Ph.D. Thesis. Colorado School of Mines, Golden, CO. (2014).
3. Tomac, I. Deformation of Jet-grouted Columns Network in Soft Soil. M.S. Thesis. University of Zagreb, Croatia. (2007).