Channel Bridge, Randolph, Massachusetts


The DCR Access Road over Route 24 Bridge (Figs. 3, 4 and 5) is beginning construction in Randolph, Massachusetts. Located in the scenic Blue Hills Reservation southwest of Boston, the 2-span, segmental “Channel Bridge” will replace an existing 4-span, steel girder structure.

The new bridge will have a length of 248', a width of 29'-8", and a total depth (including barriers) of only 5'-4". The low profile of the bridge increases the vertical clearance over the heavily traveled Route 24 from 14'-3" to 16'-9" without altering the approach grade. Additionally, the side piers of the original structure have been eliminated, thus increasing safety for the drivers on Route 24.

The shallow depth of the DCR Bridge is achieved by using edge beams located above the deck surface that function as both main supporting members as well as bridge barriers. The edge beams are fully post-tensioned, using a mix of 19-strand and 12-strand tendons. Additional longitudinal tendons are provided in the deck slab, using flat 4-strand tendons. Transversely, the structure is fully post-tensioned using flat 4-strand tendons.

Demolition of the existing bridge, construction of the new substructure, and precasting of the superstructure segments are scheduled to begin in late summer. Erection of the new superstructure segments will begin in spring 2010, with the bridge scheduled to open in October, 2010.

Project Details


Massachusetts Highway Department


Purcell Associates / International Bridge Technologies, Inc.


R. Zoppo Corporation

Construction Engineer:

FINLEY Engineering Group, Inc.

Construction Engineering Inspection:

Massachusetts Highway Department

Formwork for Precast Segments:


Post-Tensioning Materials: