Bridge Project (he only comes here when he wants something)

[TomPenny]

yep that been my thinking all along about the length and double culverts.

I didn't put these inI took over maintaining the property a while back. You cannot tell from the pic but this is actually an upscale neighborhood. There are suburbs all around it. This small stip of land is landlocked by lawns, landscaped areas and ornamental fences. So when I say mowers only it's pretty much the case.

I think my 1st step is going to be cleaning it out so I can pull these culverts out. Start from the beginning.

 

[EddieWalker]

Allot of city and county culverts and river banks are built up with cement sacks. I did the same with mine. You just get the smaller sacks since the height of the sack is what's important. A 40 or 50 pound sack is just as tall as an 80 pound sack, but not as long. No need to pay for a wider 80 pound sack for stacking them.

Dig back on both ends of the culverts. It's just as important to protect the back end as it is for the opening. Then start laying them out. Once you have them in place, hammer lengths of rebar through them. This will tear open the sacks and allow the concrete to mix with one another and it will also lock it all together when the cement sets.

If I have water available, I'll dump a few buckets over the sacks to get things started, but in time, they will get enough water to cure on their own. Just don't do this right before a big storm.

Here's one of my culverts.

Eddie

 

[jinman]

Tom, when I looked at your first picture, I could just see water going over the culverts about 1' deep. Your single culvert picture looks like it had that in mind and was designed to let floods top it. I suspect that even two culverts will not take the flow from a flash flood. If there are developments in the area, all those lawns, streets, and concrete shed water. I'd start from zero like you are planning and build culverts for the 90% flow and the entire bridge to withstand being topped in a flood for the final 10%. I think you have to design the top so water won't erode from the top down as well as the sides of the culverts. If you use a single culvert, you only have two sides to deal with. If you stick with two culverts, you have that center section between the culverts to stabilize and that makes a much more complex structure in my opinion.

 

[TomPenny]

Thanks eddie I like that. I was already reeling thinking about it then jinman chimed in and hit the breaks.

This is a very good point. Without proper engineering I cannot impeed the water flow any more than it is. Upstream from there are some houses.

Im not sure water has ever topped this. The errosion seems to caving in at this point. Doesn't matter, this is one of those time when way over allow for something.

I going to head today and take more pictures. Thanks guys and good thinking.

 

[Eagleview]

People make the mistake of using say for instance 2 x 2' pipes instead of 1 x 4' pipe . A 4' pipe has nearly 1/3rd more area than 2 x 2' pipes .

 

[YM-135trac]

Tom, when I looked at your first picture, I could just see water going over the culverts about 1' deep. Your single culvert picture looks like it had that in mind and was designed to let floods top it. I suspect that even two culverts will not take the flow from a flash flood. If there are developments in the area, all those lawns, streets, and concrete shed water. I'd start from zero like you are planning and build culverts for the 90% flow and the entire bridge to withstand being topped in a flood for the final 10%. I think you have to design the top so water won't erode from the top down as well as the sides of the culverts. If you use a single culvert, you only have two sides to deal with. If you stick with two culverts, you have that center section between the culverts to stabilize and that makes a much more complex structure in my opinion.

Thread title caught my eye. I thought somebody else met my neighbor/"he only comes here when he wants something."
I think jinman is right on. Ironhorse is a boni-fide, card-carring genius(his pic gallery proof)Eddie has cute kid and does nice work. I have seen corrigated culvert(after dug out) worn on one side 1yr. old placed in a turn in the creek. Shocked me? Once worn sink-holes appear dead smack in the middle of the dike? Hard to believe water and sand/soil can do that to metal? keep cuverts straight with the creek. just food for thought

 

[TomPenny]

I took some more pics today

 

[EddieWalker]

Something I was thinking.

Who installed the original culverts and how were they sized? My question is based on your liability. If you change it, then you become responsible of what might happen if your change fails. With homes in the area, that might be very expensive.

Leaving them there and working on improving them should protect you from any liability issues.

Good luck,
Eddie

 

[TomPenny]

yeah I might agree. Its not very likely but who wants to go around building things that might fail.

 

[jinman]

I took some more pics today

Wow! Tom, the 2nd set of pictures really looks scary. I like the nice big bridge with the columns and iron, but even it has some problems with erosion around the edges from water flowing off the top of the bridge and normal flow.

Looking at your ditch, I'd like to propose another solution. How about a low-water crossing with no culverts at all? I'd bet they will never cross that bridge right after a hard rain when the water is high. Most of the time, the depth will be 6" or less. Why not just dig out a roadbed across the ditch and pour a concrete crossing? You can put some piers down in the creekbed to stabilize the concrete. That way you do not restrict any water flow and you have a nice solid roadbed across the ditch. It won't look as pretty, but it just might be more functional over the long haul than building a culvert bridge.