The purpose of this project was to replace the structurally deficient bridge over Walker Brook. As part of the Municipal Small Bridge Program Application, an inspection was conducted which found the superstructure and substructure to be in fair/poor condition.
The existing single span bridge, comprised of steel beams with jack arch deck bays, supported on reinforced concrete abutments and stacked stone masonry wingwalls, is proposed to be replaced with a new single span 3-sided precast concrete box culvert structure placed on precast strip footing. The work under this project will consist of a full bridge replacement, including deck, superstructure and substructure due to the existing bridge being structurally deficient and functionally obsolete.
The proposed pavement width on the bridge is approximately 29 feet, with a 15’-5” travel lane on the west side and 13’-7” on the east side of the roadway. The proposed width of the approaches will match the existing width of 24.5 feet on the north side and 26 feet on the south side. The final roadway profile is being raised by 0.7 feet to meet the required grades over the proposed box culvert.
This proposed bridge structure is a single span 3-sided precast concrete box culvert structure with approximately 16” thick deck slab and 17’ span length. This structure provides precast wall attached to the precast deck structure. The existing guardrail will be replaced with crash tested S3-TL4 bridge railing with safety curb on each side. The 3-sided box culvert will be placed on precast strip footing. Stage construction is proposed to construct the 3-sided box culvert. Natural stream bottom is beneath the proposed bridge will be reestablished.
The proposed project is located within an ACEC (Areas of Critical Environmental Concern); therefore, several environmental permits were required for these proposed improvements. We worked closely with the Town and multiple regulatory agencies to procure permit approvals for several environmental permits. These permits included preparing and submitting an Environmental Notification Form (ENF) to MEPA; a Notice of Intent to the local conservation commission; a Water Quality Certificate to MassDEP; and a 404 U.S. Army Corps Pre-Construction Notification permit to ACOE.
As part of a consultant for Town of Townsend, Green is responsible for preparing final design plans, specifications and estimate for this bridge.