In 2016, DJ&A completed a bridge replacement study to evaluate design alternates for the replacement of two failing iron footbridges on the Windfall Lake trail system near Juneau, Alaska. Severe abutment failure was clear on one footbridge, where the abutment had begun to collapse. Project requirements included:
- Initial site visit to evaluate current conditions
- Recommendations for alternatives, including cost estimates and value analysis
- Topographic survey
- Hydrologic survey
- Geotechnical investigation
Based on the review of the bridge replacement study by the Tongass National Forest, DJ&A was then tasked with the design of a new steel truss stringer bridge for both sites. Substructure design included treated timber sills placed on a compacted gravel base.
- Performed site reconnaissance
- Performed geologic, minor geo-technical, hydrologic, and hydraulic analyses
- Estimated earthwork quantities
- Conducted trail realignment and alteration of existing specifications
- Produced site & contract drawings and design detail
- Produced cost estimating and load rating calculations
- Finalized design and delivery of PS&E package
Work was of high professional quality.