Highway & Traffic Design
SAKONNET RIVER BRIDGE
Portsmouth/Tiverton, Rhode Island
KEY DESIGN ELEMENT: Bridge Replacement
CLIENT: Rhode Island Department of Transportation
CONSTRUCTION COST: $163+ Million
CONSTRUCTION DATE: 2009-2014
Project Description:
The Sakonnet River Bridge No. 250 carries Route 24 over the Sakonnet River. The bridge spans approximately 3,000 feet and carries in excess of an average of 40,000 vehicles per day. Commonwealth Engineers & Consultants, Inc. was retained to conduct an extensive investigation, testing and comprehensive field review to determine the extent and type of repair work required.
Based on the complete inspection and testing program, a report was prepared outlining the proposed rehabilitation work and an associated cost estimate. Based on the high initial cost estimate, an independent value engineering was undertaken, which also investigated the cost effectiveness of constructing a new bridge.
The project went through an Environmental Impact Statement (EIS) process which considered the environmental and socioeconomic impacts of various alternatives, including both rehabilitation as well as structure replacement. The final recommendation of the EIS was to replace the bridge on a new alignment just to the south of the existing bridge.
Commonwealth Engineers & Consultants, Inc. Is currently under contract for construction services environmental compliance monitoring and traffic control on-call services.
PAWTUCKET RIVER BRIDGE
Pawtucket, Rhode Island
KEY DESIGN ELEMENT:
Bridge Rehabilitation or Replacement
CLIENT:
Rhode Island Department of Transportation
CONSTRUCTION COST:
$140 Million
CONSTRUCTION DATE:
Spring 2010 (anticipated)
PROJECT DESCRIPTION:
The existing Pawtucket Bridge No. 550 is a five-span, two-girder, pin and hanger (suspended cantilever) steel bridge which carries Interstate Route I-95 over city streets as well as the Seekonk River in Pawtucket, Rhode Island.
Commonwealth Engineers & Consultants, Inc. (CE&C) conducted an extensive investigation and comprehensive field inspection of the bridge. Excessive deterioration was found at the cantilevered sections of the floor beams, top flanges of the interior floor beams, and top and bottom flanges of the longitudinal girders and stringers. This information was used to perform a load rating and capacity analysis for the as-built condition. The structural evaluation also included a fatigue-remaining-life analysis and assessment.
Due to the high cost of rehabilitation and the low live load capacity rating, the bridge is scheduled to be replaced. Extensive construction phasing is required to maintain all travel lanes of both northbound and southbound of Route 95, which will be widened to accommodate traffic during construction as well as a new collector-distributor road for the traffic interchange at the bridge site.
As a result of partnering with State, City, and private citizens’ groups, a steel open-spandrel deck arch structure was selected for the Pawtucket Bridge No.
550 replacement, with selective use of simple, geometric design elements to suit the architectural style of building in the region. High-efficiency lighting is used extensively for both highway and accent illumination. Roadway approaches are constructed using mechanically stabilized earth (MSE) retaining walls, and includes construction of three new approach bridges, and reconstruction of three existing approach bridges.
Construction is scheduled to begin in the spring of 2010.
EAST SHORE EXRESSWAY BRIDGE 475
McCORMICK QUARRY BRIDGE 476
East Providence, Rhode Island
CLIENT: RI Department of Transportation
CONSTRUCTION COST: $12.7 Million
CONSTRUCTION DATE: 2015 - 2017
Project Description: These two bridges carry northbound (Br 476) and southbound (Br 475) East Shore Expressway traffic over US Route 6 in East Providence, RI.
The original East Shore Expressway Bridge No. 475 was a three-span continuous, reinforced concrete haunched girder superstructure with concrete substructures. McCormick Quarry Bridge No. 476 was a three simple-span-concrete I-Girder superstructure with concrete substructures. They were replaced with single-span steel plate-girder superstructures, composite with the concrete deck, supported on Geosynthetic Reinforced Soil (GRS) abutments. As an Accelerated Bridge Construction (ABC) Project, the new bridge superstructures were built off-line and moved into final location via Self-Propelled Modular Transporters (SPMT). Other ABC features included the use of precast elements for all substructure components.
Commonwealth Engineers & Consultants, Inc. was responsible for the complete design of both structures, including preliminary studies, geotechnical and structural analysis and design, and final contract document preparation. In June of 2018, CE&C collaborated with RIDOT on an international webinar showcasing this project for the Florida International University ABC/UTC Series. A pdf of this presentation can be downloaded HERE.
The project initial approach was as a conventional construction phased bridge replacement project. For the conventional construction method, CE&C evaluated and conducted:
accident data research
ATR traffic counts
vehicle classification counts
delay analysis
detour route analysis
TMP & MPT development
ROW impact evaluation
user cost analysis
traffic mitigation
Phase I & II ESA’s
TPAR evaluation
The conventional phase construction traffic impact analysis determined that there were significant traffic delays, a construction bypass roadway was needed, ROW, site disturbance, cost and construction duration were significant. As part of the ABC analysis additional traffic data was collected along the preferred detour route including:
• signal timing plans • MTM counts
• signal equipment inventory • intersection monitoring
• parking inventory • queue analysis
The additional traffic data collected was then modeled using VISSIM and Synchro software. The resulting analysis determined significant traffic congestion at critical intersections. Traffic mitigation measures were proposed and signal timing adjusted during the road closures, duty officers were positioned to keep intersections flowing and public notifications and advisories posted on the RIDOT web and public radio.
Relevance and Innovations: Rehabilitation studies and cost estimates, bridge inspection, Accelerated Bridge Construction (ABC), Geosynthetic Reinforced Soil (GRS) abutments, submittal reviews and construction consultation.
PUTNAM PIKE
Smithfield, Rhode Island
KEY DESIGN ELEMENT: 1R Roadway Improvements and Road Diet Contract 2A West Greenville Road to Austin Avenue
CLIENT: Rhode Island Department of Transportation
CONSTRUCTION COST: $ 2.5 Million
CONSTRUCTION DATE: 2009-2010
PROJECT DESCRIPTION:
Commonwealth Engineers & Consultants, Inc. evaluated the traffic capacity and feasibility of changing this 1 mile highway segment from four narrow travel lanes to a 3-lane cross section consisting of one lane in each direction and a two-way-left-turn-lane in the center. This road diet was incorporated into the construction and is performing well.
Streetscape improvements included ADA accessible concrete sidewalks, flashing school speed signs, crosswalks and a new period style traffic signal system.
Structural repairs were made to the West Greenville Road Bridge with drainage improvements to correct roadway flooding issues.