On Oct. 22, students from CU Boulder's engineering geology class (CVEN 3698) embarked on a field trip to explore the Chimney Hollow Dam project, an active construction site located to the west of Berthoud, adjacent to Carter Lake.

Todd Loar, a senior geological engineer for the U.S. Army Corps of Engineers and an adjunct professor who led the trip, said the site visit and project engineers provided valuable insights to the students.

"There's no classroom substitute for standing within and walking around a large civil construction project, where you can truly grasp its magnitude, scale and the equipment required to successfully build it," he said.

The Chimney Hollow project encompasses a 365-foot high, asphalt core rockfill dam, an inlet-outlet tunnel, a valve house and control structure, a box culvert spillway, an earth fill saddle dam, and construction facilities including a rockfill quarry, asphalt batch plant and an aggregate processing plant which provides all the project materials.

Since it was a Sunday and no active construction was occuring, the students had the opportunity to freely explore the project features and observe the construction and engineering elements close up. They engaged in discussions about the project with engineers from Stantec, including topics such as the project's purpose, geologic and geotechnical site conditions and characterization, technical engineering analysis and design features, construction processes, operational aspects, geological and geotechnical challenges and influence on the project, and the rationale behind the design features.

"The students gained a physical sense for the forces and pressures that need to be anticipated and will be exerted on the dam and its foundation, the supporting elements for a tunnel, and significant earthworks and excavations, in addition to the impact on construction quality, schedule and costs," Loar said.