Larry D. Olson, P.E.

President and Chief Engineer, M.S.

Mr. Olson is the sole owner of Olson Engineering and co-founded the company as its President in 1985 in Denver, Colorado and is internationally recognized as a leader in nondestructive evaluation of structures and infrastructure. Mr. Olson has over 35 years of consulting experience in structural condition assessment, geotechnical, pavement, materials, geophysical and vibration engineering. He has conducted and/or reviewed as the Chief Engineer over 4000 projects to investigate the condition of bridges, buildings, dams, foundations, pavements and tunnels. He is a registered Civil Professional Engineer in 21 states and the District of Columbia. He started Olson Instruments, Inc., as a division in 1993 and incorporated it in 1995 to provide instruments for nondestructive evaluation and geophysical engineering for structural and infrastructure applications.  After 31 years of working from Denver, Mr. Olson moved to northern Virginia and established our mid-Atlantic office (metro Washington, DC) in 2011 to bolster Olson Engineering's presence in the eastern corridor along with our Rutherford, New Jersey (metro New York City) office that was established in 2005. He regularly speaks and publishes on Nondestructive Testing and Evaluation (NDT&E) and Structural Health Monitoring (SHM) for construction applications and has taught short courses and/or ASCE Seminars on structural and bridge condition assessment nationally and internationally.  Mr. Olson obtained his Bachelors in Civil Engineering and Masters in Engineering (geotechnical) degrees from the University of Texas at Austin and was honored in October, 2006 as a distinguished alumni of the UT Civil Architectural and Environmental Engineering Department. Mr. Olson received patents on impact echo scanning and parallel seismic/cone penetrometer testing and has conducted a number of funded research projects on NDE and Geophysics of infrastructure.  

Phil Sirles

Chief Operating Officer and Principal Geophysicist, M.S.

Mr. Sirles joined Olson Engineering in 2013.  He earned a Bachelor’s degree in Geology and a Masters in Geophysics from Mackay School of Mines at the University of Nevada-Reno.  As Principal Geophysicist Mr. Sirles has diversified the range of geophysical capabilities for the firm's consulting services with over 30 years practice in applied geologic, engineering and environmental applications using nearly all of the surface and borehole geophysical techniques over his career.  Shortly after joining the Olson staff, it became apparent that his other business experience brings to the Olson management team over 15 years of marketing, business development and executive management, and thus was added as an Executive Officer in the role of Vice President.  The ability of Mr. Sirles to provide insight for day-to-day operational and management oversight afforded Larry Olson the opportunity to escalate Mr. Sirles’ role to Chief Operations Officer in Late 2014.  Currently, he is the Geophysical Group manager.  Mr. Sirles is identified as a SME to the Navy, and the FHWA for roles needed on large, critical, and complex engineering geophysical projects and also to train engineers in these agencies for the proper application of geophysics to a wide variety of problems.  He became accredited for training through short courses and workshops over 15 years ago.  He has conducted geophysical surveys in 46 states, and five countries internationally.  A list of Mr. Sirles’ society memberships and activities, and publications can be found below.

Dennis A. Sack, P.E.

Senior Vice President and Principal Engineer

Dennis SackBefore joining Olson in 1990, Mr. Sack had been with Northrop Aerospace as a Wind Tunnel Instrumentation Engineer. He earned his Bachelor of Science in Electrical Engineering at Cal State University, Northridge, California Magna Cum Laude and completed all of the course work of the Masters in Electrical Engineering program (Digital Signal Processing) at Cal State Northridge. Mr. Sack has a broad range of experience in NDT and evaluation of structural elements of various materials. He has extensive consulting experience in over 3800 nondestructive evaluation, vibration and geophysical investigations. In addition to his consulting service ability, Mr. Sack has been responsible for the design and development of instrumentation, both hardware and software, for over 20 years to Olson Instruments, Inc. (hyperlink). He has designed and built the electronics for the Olson Instruments Freedom Data PC, Concrete Thickness Gauge, and NDE360 Platform as well as associated transducers, pulser units and software for ultrasonic, sonic, seismic, vibration and physical testing measurements. Mr. Sack holds a patent in Scanning Aparatus and Method for Non-Destructive Materials Evaluation and Mapping Through Use of Acoustic Waves. Mr. Sack's responsibilities as Senior Vice President are varied. He manages the NDT Group in the Colorado Office, where he’s in charge of the NDT staff and responsible for all aspects of NDT consulting projects. Mr. Sack has prepared and presented a number of papers on a variety of aspects related to NDT of infrastructure, and is currently an instructor for the ASCE seminar on Structured Condition Assessment of Existing Structures. A list of Mr. Olson's PE's, society membership and activities, and publications can be found below. 

Yajai Tinkey, Ph.D., P.E.

Yajai TinkeyVice President and Associate Engineer

Dr. Tinkey joined Olson Engineering in 2000. In 2011 she was promoted to Vice President to assist Dennis Sack in managing the NDT Group and help grow the company. Dr. Tinkey has a computer engineering and structural engineering background. She obtained her Masters and Ph.D. in Structural Engineering from the University of Texas at Austin. Her Bachelor's in Computer Engineering is from King Monguth Institute Technology at Lardkrabang, Thailand and she is fluent in Thai. Her Masters work included vibration and modal studies of concrete bridge foundations. Her Ph.D. work included Acoustic Emission for structural health monitoring in steel and fiber reinforced plastics. Dr. Tinkey's executive responsibilities include business development, and project management.  She commonly is involved in field programs to supervise data acquisition and analysis and report generation for NDT projects involving condition evaluation of bridges, historic structures, dams, soils and foundations using a variety of NDT methods. Dr. Tinkey also works in load testing of bridges using Interferometric Radar Imaging of Bridge Displacements. In addition to the NDT program work, she has developed much of Olson’s software programs for in-house use and commercial distribution using Visual C++ (in Windows).  She is experienced with research/grant proposal preparation and has served as Principal Investigator in research projects with NSF and NCHRP, and also worked on research and reporting for projects that were funded by NCHRP and FHWA.

Evan Walston, CMA

Mr. Evan Walston joined Olson Engineering in 2001, working as an intern while earning his Bachelor’s degree in Economics from Colorado School of Mines.  Since 2003, he has worked his way up in the company, and Mr. Walston found that Management Accounting was his calling; as such, he obtained a Master’s degree in Accounting from University of Colorado-Denver.  As the company Comptroller Mr. Walston has brought a systematic approach to budgets and its financial reporting requirements.  

Recently Mr. Walston became a licensed CMA, which further advances his role in the company. He is also the Manager of Olson Instruments, the sister company to Olson Engineering.  Evan’s strength comes through his attention to detail, his management skills, his forward-looking approach about how to improve not only the accounting department, but the company as a whole, and ultimately his desire to grow both the businesses of Olson Engineering and Olson Instruments.