Tonon USA




Laboratory Tests on Rock - Introduction



Tonon USA rock mechanics laboratory was established in 2011 based on Dr. Tonon’s rock mechanics research as a faculty member first in Geological Engineering at the University of Utah, and then in Civil Engineering (rock mechanics and underground excavations) at the University of Texas at Austin.

Our lab specializes in rock testing with special emphasis on tunnels and underground excavations, and tests to characterize the abrasion of soils (Soil Abrasion Test (SAT), the Miller Abrasion Number, the Slurry Abrasion Response (SAR) , the LCPC Broyability and Abrasiveness) for  Earth Pressure Balance Machines (EPBs), Slurry Shields, and deep foundations. The rock mechanics lab is truly unique in the World: important examples include the Norwegian (NTNU-Sintef) tests to determine the Drilling Rate Index and the Cutter Life Index for the prediction of rock TBM performance and wear, as well as drill bit performance and consumption; the Schimazek Index for the prediction of rock TBM performance; Cerchar tests for rock abrasion and prediction of excavation tool wear for TBMs, hydromills, drill bits, and drilled-shaft chisels; and uniaxial, triaxial, and direct shear tests by means of servo-controlled apparatuses in order to:

  • Follow the post-peak behavior of the rock
  • Impose any pre-determined stress, strain or displacement history
  • Carry out triaxial tests in order to determine the effective stress parameters for the intact rock with a confinement up to 70 MPa; these parameters are important, for example, in the case of weak and/or porous rocks (e.g., siltites, calcarenites, argillites, and altered and weathered rocks)
  • Carry out multi-stage triaxial tests to determine the entire failure envelope from a single specimen (to reduce testing time and result spread), or to determine the failure envelope even when the available specimens are few.


Our 3 MN (675 kip) high-stiffness testing frame for uniaxial and triaxial tests on hard rock is specially designed and built to support the shock from the explosive failure of extremely hard rock specimens; indeed, rock specimens with uniaxial compressive strengths of 500 MPa (72 ksi) have been tested until now.


From 2009 to 2015, Dr. Tonon served as Chair of ASCE Rock Mechanics Committee , and he is a member of the ISRM Commission on Rock Fractures. Peer-reviewed journal publications specifically related to rock testing and stemming from Dr. Tonon’s lab experience include:

  1. H. Youn and F. Tonon, Multi-stage triaxial test on brittle rock. Int. J. of Rock Mech. and Mining Sci., 47, 2010, 678–684. DOI: 10.1016/j.ijrmms.2009.12.017
  2. P. Asadollahi, M.C.A. Invernizzi, S. Addotto and F. Tonon. Experimental validation of modified Barton’s model for rock fractures. Rock Mechanics and Rock Engineering, 43, 2010, 597-613. DOI: 10.1007/s00603-010-0085-6
  3. P. Asadollahi and F. Tonon, Constitutive model for rock fractures: revisiting Barton's empirical model. Engineering Geology, 113, 2010, 11–32. DOI: 10.1016/j.enggeo.2010.01.007
  4. H. Youn and F. Tonon, Effect of air-drying duration on the engineering properties of four clay-bearing rocks in Texas. Engineering Geology, 115, 2010, 58–67. DOI:10.1016/j.enggeo.2010.06.012



Our Quality System stems from our attitude to listen to our Clients' needs, our intimate knowledge of rock mechanics, and our understanding of the design and construction needs for lab testing; our Quality System is currently ISO 9001-2015 certified by DNV-GL. A copy of our certificate may be found here.


Tonon USA is a certified DBE (Disadvantaged Business Enterprise) in several States. The DBE Program is a legislatively mandated USDOT program that applies to Federal-aid dollars expended on federally-assisted contracts issued by USDOT recipients such as State Transportation Agencies.To meet the stated 8 objectives of the DBE Program Regulation, recipients of DOT funds must develop and implement a DBE program that conforms to DOT standards set forth in 49 CFR Part 23 (for airport concessionaires) and 49 CFR Part 26. If Tonon USA is not certified in your State, we can quickly become certified in your State to accommodate your project DBE requirements. Tonon USA is also a Women Business Enterprise (WBE) certified by the  California Public Utilities Commission (CPUC),  Supplier Clearinghouse Verification Order Number: 16000864.


We would be delighted to hear about your project and we would be proud to assist you with your  testing needs. Please drop us a line at, or give us a call at 512-200-3051. At the links above, you may find some initial information on our qualifications and test offerings.







Phone: +1-512-200-3051


2028 E Ben White BLVD #240-2660 - Austin, TX 78741