hutchins_appd.htm

hutchins Apendix Index

TO:                    John Weaver, Structures Project Manager
FROM:               Nick Wark, Civil Engineer III
DATE:               May 25,2005
SUBJECT:       Montgomery BHO 1448(23) TH27, Br34

The above listed project is a covered bridge rehabilitation. The bridge spans the South Branch of the Trout River. The existing bridge has approximately 11' of freeboard over Q100, so hydraulic capacity is not an issue at this site.

If needed, a temporary structure should be selected to best fit the alignment of the river and roadway. Just upstream of the existing bridge is a bend in the river. In order to span the channel upstream, the temporary structure should have a minimum span of 100'. Downstream of the existing bridge the channel has very steep banks consisting mostly of ledge. In order to span the channel downstream we suggest that a temporary bridge have a span of at least 85'. Shorter spans could be used; however we feel that placing temporary abutments on the steep ledge would be more costly than using a longer span.

Please contact us if you have any questions or if we may be of further assistance.
NJW

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