Forest Road Engineering Guidebook - Ministry of Forests

Forest Road Engineering Guidebook
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training and experience are involved and responsible for all aspects of weld
design and welding procedures.
Where shop or field welding is required, designs should indicate the minimum
qualifications required. Use of Canadian Welding Bureau (CWB) certified
firms and qualified welders is recommended.
Abutment heights, from the foundation level to the top of the abutment on
which the superstructure would bear, are limited to log cribs less than 4 m in
height or sills or pads up to 1.5 m in height. For log cribs, the 4 m height
limitation is measured from the bottom of abutment where it bears on the
ground to the top of the bearing sill or bridge soffit (underside of bridge
superstructure).
Abutments that are not log cribs are limited to 1.5 m in height. Sills and caps
are transitions to connect the superstructure to the substructure. They are not
considered part of the maximum allowable abutment height, provided the
transition depth is not excessive (a maximum sill or cap height of 400 mm is
suggested), and that the sills, caps, and the connections have been produced
from design aids prepared by a professional engineer for use in the proposed
configuration.
Note that abutment heights are not cumulative; for example, a 1.5 m abutment
is not intended to be designed to bear on top of a log crib or its fill. Binwalls
are not considered log crib equivalents. Binwall abutments are more complex,
requiring bearing of sills or pads on significant compacted fill depths, and
must be designed by a professional engineer.
Bridge designs by non-professionals and professional foresters must be prepared
using structural details provided in drawings, tables, charts, and other
design aids that have been prepared by a professional engineer. Each bridge
or major culvert must have its own site-specific design. The bridge components
(superstructure, substructure, connections) must all have been designed
to be used in the specific combination and configuration shown in the design.
Any design aids used should be referenced on the design drawings or
attached documentation.
Where portable bridges are used, the structure must have been designed or
structurally analyzed by a professional engineer. The design or analysis
should demonstrate adequacy for the intended use. Once the structure has
been reviewed and approved by a professional engineer, the structure may be
reused at new sites without specific professional engineer review, provided
that:
• a qualified inspector has inspected the bridge at the new site before any
use and detects no damage or deterioration of the structure;