I've been working on a project in Parke County, IN which entails the redesign of a covered bridge recently torched by arsonists. It is a 204 foot double span burr arch, and I've been trying to make it as historically accurate as possible to get full funding as a historical project. It has been recently requested that I also provide some computer analysis of the project so they can hopefully set a higher load limit (and of course, get more money). I know joints experience a semi-rigid behaviour (not fixed or pinned) but I am at a complete loss as to good valid results from any structural analysis type of program. Has anyone done similar things with any success, or know of a way besides computer analysis to get a reasonable (not overly-conservative) solution? I am open to any ideas.

Joe:

Ed Levin is THE person to talk to on this subject. See his article in Timber Framing # 25 on engineering the Speed River bridge in Guelph, Ontario (a former Guild project) as well as various posts in this BB including:

http://www.tfguild.org/ubbcgibin/ultimatebb.cgi?ubb=get_topic;f=5;t=000005

For more info, use the search box on the first page of the web site on the term "speed river".

Brian