Forest Road Engineering Guidebook - Ministry of Forests

Forest Road Engineering Guidebook
• the design loads to be carried should be equal to or lower than original
design loads; and
• the bridge is suitable and has been specifically designed for the new site,
and the superstructure has been fabricated and constructed in compliance
with the Forest Road Regulation.
The professional engineer, professional forester, or person assuming responsibility
must sign off on the design for the bridge or major culvert and
becomes the designer of record.
Site data and survey requirements for bridges and major culverts
The person assuming design responsibility for a bridge or major culvert
requires site-specific information for the proposed crossing. A detailed site
survey (see Appendix E, “Bridge and Major Culvert Site Plan Specifications”
in the Forest Service Bridge Design and Construction Manual) is recommended
for all bridges and major culverts. The survey information is used to
produce site plan and profile drawings for planning, developing, and evaluating
the crossing design. Direction for the type and quality of site information
to be collected and the site survey to be completed should be obtained from
the designer. Included should be:
• the riparian class for streams or lake classification
• the apparent high water elevation of the stream, based on visible evidence
of recent flooding
• a description of the composition and size of stream bed materials
• a description of stream bank materials and stream stability
• cross-sections and a profile of the crossing
• the stream flow velocity and direction, if the flow may influence the size
or layout of the structure
• a description of the soil profiles and foundation soil conditions, based on
soil explorations appropriate to the level of risk
• presence (or absence) of bedrock, and depth to, bedrock
• a description of any evidence of stream debris or slope instability that
could affect the crossing, based on upstream observations
• any existing improvements or resource values in the vicinity that may
influence the size or layout of the structure.
• if there is an existing structure, location and dimensions of the structure,
including roadway, abutment, superstructure, and stream information
• the date of the survey
• the locations and dimensions of any upstream structures, and a note about
whether they are problem-free
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