By adding a new bridge over I-270 and ramps connecting Watkins Mill Road with the interstate, residents now have easier access to locations such as the Gaithersburg Medical Center, Metropolitan Grove MARC Station, the Montgomery County Police Department and local neighborhoods and businesses.
Work on the I-270 (Eisenhower Parkway) at Watkins Mill Interchange continues in Gaithersburg, Md., in Montgomery County.
The $124 million major congestion relief project will improve one of Maryland's most heavily traveled roadways in the county, benefiting the tens of thousands of travelers who drive the I-270 corridor.
The contract was awarded to Wagman Heavy Civil Inc. with David Leber as project manager.
The project, which includes a new bridge over I-270 and ramps connecting Watkins Mill Road with the interstate, is part of Maryland Gov. Larry Hogan's investment of $1.97 billion in state highways and bridges. Montgomery County contributed $4.9 million for design and engineering.
"This interchange has tremendous economic benefits for the region and improves access to the Metropolitan Grove MARC Station," said Hogan. "The men and women of MDOT SHA have delivered a critical link in this employment corridor that will advance our economic recovery as we continue to reopen Maryland."
Shanteé Felix, assistant media relations manager of the office of communications of MDOT SHA, reported that the project started in August 2017. At the beginning of November, it is approximately 99 percent complete.
The interchange opened on June 10, but crews are continuing to work on lighting/traffic signal structures, landscaping, bridge painting and punch list items.
The project connects both sides of Gaithersburg to jobs, transit and businesses in Montgomery County's Technology Corridor. By adding a new bridge over I-270 and ramps connecting Watkins Mill Road with the interstate, residents now have easier access to locations such as the Gaithersburg Medical Center, Metropolitan Grove MARC Station the Montgomery County Police Department and local neighborhoods and businesses.
"We had a variety of challenges with this project that include communication duct bank relocation, mechanically stabilized earth [MSE] retaining wall installation and working within an existing tributary," Felix said. "The Level 3 communication duct bank was supposed to be relocated before the project entered the construction phase, but it was not. We were able to mitigate its impact on the construction schedule through meetings and a cooperative effort for a new utility alignment."
She noted that originally, the MSE retaining wall was to be installed under two towers supporting high voltage power lines. However, preliminary engineering concluded that there was no room for a safe slope for excavation. A proper Support of Excavation (SOE) system was designed and implemented to avoid any impact on the project schedule.
"Another challenge was building a new interchange within the footprint of an existing tributary to Seneca Creek," Felix said. "Most of the interchange structures had to be built concurrently with the relocation and building a floodplain of a mile-long tributary stream. We had to find a way to schedule the work so stream flow would not be interrupted and also minimize the impact to aquatic life."
Additionally, Felix noted that erosion and sediment control best management practices were constantly challenged by the weather and large area of impervious ground upstream of tributary that was being relocated within the project limits.
"This project is unique because it is a complex interchange consisting of one mile of stream restoration and relocation, two [five and two span] bridges, three culverts, five cast in place [CIP] walls, and six MSE walls," Felix said.
Most of the structures were built in concurrence with the stream restoration and next to/over a major interstate highway.
"The I-270 Technology Corridor is an important component of our economic development plans to support dozens of thriving businesses that are industry leaders in biotechnology," said Montgomery County Executive Marc Elrich. "This long-awaited and much-needed interchange will help support our plans to enhance economic development and provide traffic relief in the northern part of the county … It is a step toward addressing our evolving transportation needs, but more importantly it symbolizes a bridge from our past to our future."
The project includes 2.3 mi. of four lanes with shoulders resurfaced, 2.2 mi. of one and two lanes of new ramps. More than 320,000 cu. yds. of earth were moved and more than 22,700 cu. yds. of concrete placed.
Major subcontractors for the job include Bulldog Distribution for trucking services; DRM Associates Inc for installation of stay-in-place metal deck forms and shear studs; Ed's Plant World Inc. for landscaping; Guardrails Etc. Inc. for guardrails; Hardscapes Construction Inc. for MSE walls; Harvest RGI LLC for clearing and grubbing; Interlock Steelworkers Inc. for concrete steel reinforcement; Jemco Inc. for drilling and rock blasting; D.W. Kozera Inc. for geotechnical services; Lems Contracting Co. Inc. for landscaping and E&S control; Long Fence Co. Inc. for fence installation; Olympus Painting Contractors Inc. for bridge painting; Ox Construction LLC for underdrains; Pessoa Construction Co. Inc. for concrete traffic barriers; W.F. Wilson & Sons Inc. for WSSC sewer and water lines; Piping and Corrosion Specialties Inc. for WSSC water lines; Pleasants Paving for asphalt paving; Roads Safety LLC for road signs and temporary crash cushions; Snyder Environmental Services Inc. for 30-in. RCP jack and bore; Specialty Services Inc. for road signs; Stolar Construction for traffic signalization and lighting; and Zone Striping Inc. for pavement marking.
Equipment used on the job was all owned by Wagman. CEG