u/AwfullyJoyous

60 second recovery on Metcon day? What were they thinking??

It's a real canoodle.

It's a relatively small channel that spills onto a very large floodplain, such that the majority of the total Q100 is flowing in the overbanks at every cross station in a 2000-ft reach. Almost the entirety of this wide floodplain is mapped as FEMA Regulatory Floodway.

County has a dangerous sightlines one-lane bridge over this floodplain that they want to replace for both roadway safety and structural need in the bridge itself. Achieving both of these goals while essentially not touching a speck of dirt in the process is, I would say, impossible: any improvement will trigger an increase of the existing WSE of at least 0.01 ft.

Meanwhile, of course, client demands there must not be a CLOMR. Got it.

Well, we got our proposed structure as close to the existing as we could to satisfy safety/roadway while stay extremely close to existing grade. And the proposed model is now stuck at about 0.2 ft rise in WSE.

Proposed bridge has a larger open area but a 35-degree skew to the creek (bad, should be 2D), whereas existing had a 20-degree skew. Model now differs only in the upstream bounding cross-sections of the existing & proposed, rest of cross sections model identically.

Skew in general appears to have the most weight towards lowering the WSE delta, i.e. if I change the proposed to 20-degree skew, the WSE delta becomes closer to 0.02 ft max.

My gut tells me there's a hydraulic scenario that a correctly situated proposed and graded bridge can be designed at a greater skew than the existing bridge without causing resulting increase to WSE.

I could go on -- but just curious if this story rings true for anyone. Any insights would be greatly appreciated!

Note: If your insight is that we need to just accept going through the CLOMR process ... we're not "there" yet.

https://preview.redd.it/g01rye0028gh1.png?width=1423&format=png&auto=webp&s=342bfecea306def045e93a245dfbecb1decacb91

I'm going to be in town for work Tues-Thurs in a couple weeks. I'd love to experience a little local evening fun. Not expecting *much*, but where could I potentially find a lively spot on a Tuesday or Wednesday evening, Harrisburg proper or on the west side?