Odell, New Hampshire
D&K, through an on-call contract for Soil Conservation services, designed a fish friendly and cost-effective, 38-ft-span bridge suitable for logging trucks. The new bridge replaced an undersized 7-ft culvert that was a barrier to fish passage and was contributing to channel instability due to upstream deposition and downstream scour. The design of the bridge abutments consisted of stacked concrete waste blocks set back from the channel to reduce scour potential. Large angular riprap was used to further protect the abutments from scour, but was concealed by native cobbles and boulders. The bridge superstructure consisted of pre-engineered steel framing with timber decking. Total construction cost was less than $50,000 and the entire construction sequence, from removal of the old culvert to final seeding and mulching, was completed in only five days. Project was completed under the Wildlife Habitat Incentives Program (WHIP).
DuBois & King’s water resources and structural engineers provided the following services:
Survey
Wetland delineations
Stream geomorphic assessment
Fish passage evaluation
Natural channel restoration
Hydrologic and hydraulic analysis
Evaluation of alternatives for bridge and culvert design
Evaluation of alignment alternatives using computer simulated truck turning movements
Coordinated abutment design with superstructure manufacturer
Analyzed and designed substructure for internal and external stability
Permitting
Construction documents
Cost estimates
On-site engineering support during construction
Stream Crossing-
Stream Crossing
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Stream Crossing
