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.
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.
Todd Schlittenhart, PE
Director of Engineering Services
Todd Schlittenhart is the Director of Engineering Services. He has over 20 years of experience in the geological, geotechnical and highway construction related fields. His expertise includes geotechnical exploration, soil and rock slope stability analysis, mechanically stabilized earth walls, soil nail walls, rock and soil anchors, geotechnical instrumentation, and construction management. He has managed numerous construction and design teams in Colorado and Wyoming for a variety of public and private sector projects, often in difficult terrain.
Calvin Yeh, PE
Director of Administrative Services
Calvin Yeh is the director of Yeh’s administrative services. After completing his undergraduate degree at MIT, he obtained a master’s degree in geotechnical engineering from CU Boulder. Calvin has over 10 years of project management and geotechnical design experience, working on diverse projects from major infrastructure and large design-build deliveries to public and private commercial development. His design experience includes work in foundation design, settlement analysis, landslide mitigation, slope stability analysis, retaining wall design and various types of construction observation.
Clinton Moyer, PE
Director of Construction Services
Clint Moyer is the Director of Construction Services. He brings over 20 years of civil engineering experience including 15 years with the Colorado Department of Transportation with the last 6 years in Region 3 as a Resident Engineer. Clint has provided construction management services for local agencies, CDOT, and FHWA with project scales ranging from resurfacing projects to full interchange intersection replacements and bridge replacements. Clint’s experience includes asphalt and concrete roadway rehabilitation projects, bridge replacements, schedule review, constructability review, and claims avoidance/review.
Jon Blanchard, GE, PE
Director of Pacific Region
Jon Blanchard has been providing geotechnical services in California for more than 30 years. He is experienced in the design and management of public works infrastructure throughout California and other western states. These projects include managing and leading geotechnical services for the design and construction of transportation systems, bridges, pipelines, water reclamation and storage, flood control, earth retention systems, and mitigation of geologic hazards for large landslides, coastal erosion, liquefaction and faulting. His experience includes projects for local agencies and universities, the Caltrans and working with other state agencies, and federal funded projects in California, Nevada and Arizona.
Pete Mertes, PE
Director of Branch Management