Projects – Page 15 – DuBois & King, Inc.

Wolcott Hydro Dam Safety Inspection, Design of Repairs, and Breach Analysis

DuBois & King performed a dam safety inspection and evaluation of a 90-year-old, hydroelectric dam owned by the Hardwick Electric Department. The dam is a 384-ft-long, 52-ft-high concrete gravity dam founded on bedrock with an ogee spillway. As part of the inspection, the dam’s hazard classification was reconfirmed. Recommendations and priorities for rehabilitation measures were identified. A breach analysis and inundation mapping were also performed to properly inform revisions to the Emergency Action Plan. Professional services included:

Identification and evaluation of deficiencies
Inspection report (findings/priorities for maintenance program)
Confirmation of classification as a High Hazard Dam
Recommendation for revised Emergency Action Plan
Breach analysis
Inundation mapping
Design of repairs, including a yielding flashboard
Permitting for dredging of sediment

Windy Acres Cooperative Water Line Improvements

DuBois & King provided multidiscipline services for a water line improvement project at Windy Acres Cooperative, a manufactured home park in Charlestown, New Hampshire. Project included coordination with park board members and funding agency. Water line replacements were performed along First and Second Streets for a total of 1,650 lf of replaced line. Original mains were 2-inch and replacement mains were 4-inch PVC C900. Design involved review of a complex series of conflicting utilities and considered several alternatives. Services included topographic survey, conceptual plan layout of proposed water line, preparation of final construction documents, permitting, construction specifications, and bid and construction phase services.

D&K engineers established an aggressive project schedule to deliver the design within a very short time frame in order to meet owner objectives for late fall construction. This was an ARRA-funded project with a limited budget. Successful delivery of the design on time and bid documents with strategic bid alternatives allowed the owner to construct all aspects of the project.

Windham Depot Area Improvements

Prime consultant and site engineering services for rehabilitation of a historic district facility. D&K engineers worked with the Town of Windham’s Administrator and the Windham Depot Advisory Committee to prepare design documents (plans and specifications) for the stabilization of the existing Depot Train Station and Freight House buildings and construction of parking and open/common-space for users of the Windham portion of the Salem to Concord Bikeway. The project was funded by an NHDOT Transportation Enhancement (TE) grant, the Federal American Recovery and Reinvestment Act (ARRA), and the Town of Windham. Services included site design, stormwater management, erosion control management, site landscaping, environmental permitting, and architectural coordination. Project included:

Rehabilitating train/freight buildings to mimic original condition
Installing new electrical, toilet facilities, and cosmetic improvements
Constructing 37 parking spaces to service Salem to Concord bike path
Constructing parking for winter motorized/equestrian recreation
Creating a green space and picnic area space

Whittier Covered Bridge Design-Build

The design-build team of DuBois & King and 3G Construction provided design and construction services for the rehabilitation the 132 ft long, single span Whittier Covered Bridge. This one lane bridge, constructed in the 1870’s, utilizes a Paddleford Truss, a unique framing style only used in a few northern New England covered bridges. The bridge superstructure was moved off the abutments and relocated on land on the south approach road. Project includes repair/replacement of deteriorated/broken timber members, increasing live load capacity to 6 tons, increasing snow load capacity of roof members to comply with current code requirements, and increasing wind resistance capabilities of all lateral bracing members.

A three-dimensional computer model was made of the superstructure for analysis of all loading conditions and to identify members needing to be strengthened. Completed field observations and condition assessment report with recommendations and cost estimates for extensive repairs. Repairs include strengthening roof purlins for snow loads; modifying lateral brace member connections for increase wind load resistance; replacing deteriorated (rotted) truss chord and truss diagonal members; and repairing/replacing stringers, floorbeams, and lower lateral bracing. Prepared preliminary repair/rehabilitation drawings and submitted to the NH Division of Historic Resources and the NH Department of Transportation for review and concurrence. The project received a National Historic Covered Bridge Preservation Grant. Services include:

Assessment of existing conditions
Preparation of investigations/recommendations report
Preparation of contract documents

White River Junction VA Medical Center Electrical Upgrades

Design and construction phase services for $2.9 million of upgrades to electrical systems at the White River Junction VA Medical Center. The facility is a 450,000-sf, 64-acre, multi-building campus that includes offices, in-and out-patient hospital care areas, cafeterias, and support functions.

More than 300 electrical system deficiencies were addressed to achieve campus-wide improvements in reliability, serviceability, safety, energy efficiency, and emergency power. Complex, detailed construction phasing was developed to assure all active areas of the hospital would function without interruption during construction. Where deficiencies were addressed, lighting costs were cut in half while providing additional and improved lighting and control.

The electrical distribution included upgrades to the 5kV and 15kV medium voltage and low voltage distribution systems. New switchgear was provided along with reconfiguration to allow for servicing without interruption of power to the 15kV medium voltage system. Inside the facility, the existing low voltage distribution systems were upgraded to replace obsolete equipment.

The interior lighting system upgrade work included most of the facility buildings, requiring identification of the existing inefficient light fixtures, performing lighting calculations (photometric plans), and design for new high performance fixtures. Campus wide photometric site plans were developed to replace metal halide exterior site lighting with energy efficient LED lights. Lighting calculations were completed to provide for appropriate lighting levels for security and pedestrian access to the buildings. More than 90 exterior fixtures were replaced. The new LED lights require one-half of the wattage of the replaced metal halide lamps. The lighting improvements significantly reduced energy usage and costs. Exterior lights are dimmable and computer controlled via wireless radio control. More than 1,600 interior fixtures and 145 exterior fixtures, including 91 pole fixtures, were designed for replacement or to supplement lighting for security.

The project received a Merit Award in the ACEC/VT Engineering Excellence Awards program.

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