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Our Mission

To better our world using innovative and efficient geotechnical, geological, and construction solutions.  Through our commitment to being high-quality, trustworthy people, we bring together a team of passionate professionals to provide value-added, responsive service to every community we have the privilege of serving.

Quality  | Innovation, Expertise, and Efficiency Integrity and Community |  Service  |  Teamwork and Safety

Firm Profile

Yeh and Associates is a full service firm specializing in geotechnical engineering, engineering geology, and construction management, established in 1999.

Our extensive professional engineering experience includes traditional investigation services, geologic hazard evaluation, and geotechnical evaluations supporting the planning, permitting, design and construction of infrastructure projects. Some of the design services include soil nail walls, mechanically stabilized earth walls, micropiles, anchor systems, soil improvements and various pavement structures. 

Our construction services include materials testing, construction observation and construction site management support.

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Shan-Tai Yeh, PE

President and Founder

Shan-Tai Yeh is the President and Founder of Yeh and Associates. He has 38 years of geotechnical engineering experience, including 13 years with the Colorado Department of Transportation where he supervised the Soils, Foundation, and Engineering Geology units and also was the Chief Engineering Geologist. Located in our Denver, CO office, Shan-Tai serves as the Principal-in-Charge for geotechnical investigations, design, and inspection projects.


Rick Andrew, PG

Vice President

Our Vice President, Rick Andrew, has 32 years of experience in the geotechnical engineering and engineering geology field. He is noted for his ability to identify and provide the necessary expertise to challenging and complex projects. Rick was employed by the Colorado Department of Transportation for 10 years as a Senior Engineering Geologist. His background in geotechnical related construction and rock excavation provides our team with a unique perspective on geological and geotechnical engineering. He has managed numerous geological investigations and design teams primarily in challenging terrain and fragile environments.


Jon Blanchard, GE, PE


Jon Blanchard has 30 years of professional experience in project and contract management, corporate planning and operation, office management, business development, construction management, and expertise in geotechnical engineering. He has provided geotechnical and construction services for more than 50 bridges, nearly all wastewater treatment facilities on Central Coast, flood control dams and levees, and various other projects throughout California. Jon is the Pacific Region manager for Yeh and Associates’ engineering and construction projects in California and Nevada.


Ed Archuleta, PE

Principal and Western Regional Manager

After 18 years of service with the Colorado Department of Transportation, Ed Archuleta recently joined Yeh and Associates as a Principal in our Durango office. Ed brings his CDOT expertise as a Senior Project Engineer with responsibilities for managing a staff up to 50. At Yeh and Associates, he serves as the regional manager for design and construction projects in Western Colorado, New Mexico, Arizona, and Utah.


Bill Scheuerman, PE

Principal and Manager of Construction Services

Bill Scheuerman has been the Manager of Construction Services for Yeh and Associates for the past four years. Previously, he was employed for 28 years with the Colorado Department of Transportation – 16 years of which were spent as Resident Engineer. In that role, he was responsible for projects from planning through construction. He oversaw the construction of a wide variety of project types from complex urban projects to more rural eastern plains projects. He currently manages the Yeh and Associates’ FHWA construction management contract and works proactively with clients to manage staff resources.


Reza Akhavan, PE

Principal and Manager of Engineering Services

Reza Akhavan is a Principal with the firm and has over 30 years of engineering experience including planning, design, construction, operations, and program management in both public and private sectors. Reza has successfully delivered numerous complex infrastructure projects locally and regionally. As the former regional transportation director for the Colorado Department of Transportation Region 6, Reza directed the overall transportation program for the Denver metropolitan area. Prior to joining Yeh and Associates, Reza was the Division Vice President of Operations for the Rocky Mountain region of an International A&E firm.