Brudis & Associates, Inc. (BAI) provided preliminary and alternative design analysis to improve safety conditions at the project location. The $1.1M replacement bridge was warranted due to multiple deficiencies that posed a threat to public safety including substandard guardrails, potential bridge collapse due to flooding and erosion, low posted weight limit, limited sight distance, and insufficient road width for safe passage of two-way traffic. Harford County determined complete replacement of the existing bridge (constructed circa 1940) was more cost effective than repairs over the long term. Harford County Department of Public Works and Maryland State Highway Administration partnered with BAI to design a unique replacement bridge solution that emphasized value and cultural community aesthetics.
Services included the development of complete engineering design plans, specifications, and estimates for the structural design, roadway design of the bridge approaches, hydraulic and hydrology studies, design of stormwater management and erosion & sediment control measures, waterway construction permitting, geotechnical investigations, topographic survey and mapping, drainage design, maintenance of traffic, bridge scour analysis, wetland delineation and mitigation, bridge alternative analysis, cultural resources analysis, environmental permitting, signing, pavement markings and construction phase services.
Structure Design: As the result of alternative analysis, a 38’ span cast-in-place deck supported on shallow pre-stressed concrete beams was selected for the replacement bridge to improve hydraulic performance and safety. Pre-stressed concrete limits the risk of cracking, reducing maintenance costs and increasing longevity of service. The design also increases the load capacity to 20 tons to ensure safe passage of heavier vehicles. (The average school bus without passengers weighs more than 10 tons. The new structure was designed using AASHTO LRFD Bridge Design Specifications for an HL-93 live load using four (4) four 48”x15” prestressed concrete beams for the new 38’ bridge span.)
Water Resources and Environmental: BAI provided erosion and sediment control design, stormwater management, drainage, bridge hydrology & hydraulic design, bridge scour and environmental services. BAI developed SWM improvements by utilizing non-structural practices such as grass channel credit, sheet flow to buffer, and sheet flow to conservation areas. BAI coordinated with all environmental regulatory agencies for wetlands, waterways, SWM and erosion and sediment control.
Highway/Traffic: BAI was responsible for maintenance of traffic, highway design, and approach roadway design. BAI prepared Traffic Control Plans (TCP) for a complete bridge closure and submitted the plans to the County and State for approval. Highway design included developing typical roadway sections showing both the bridge and approach roadway sections, based on an open section, 20’ roadway with 3’ shoulders. BAI established horizontal baseline of construction, vertical profile geometry, and prepared geometric plan in accordance with AASHTO criteria. BAI prepared design plans for the approach roadways to increase design speed to 30 MPH. The new vertical alignment also provided a smooth transition to the existing approach roadways and improved sight distance and safety.
Established horizontal baseline of construction, vertical profile geometry, and prepared geometric plan in accordance with AASHTO criteria. BAI prepared design plans for the approach roadways to increase design speed to 30 MPH. The new vertical alignment also provided a smooth transition to the existing approach roadways and improved sight distance and safety.