Small creek bridge abutment design?

[Slackdaddy]

If it’s out in the middle of nowhere you might be ok but…………

"Might be" is the key part,, I am to old to sleep worrying about getting nailed

Where I grew up in California, a buddy had some land next to a Park. The Park Police and Rangers where always messing with us because his easement allowed us to drive through the Park, but vehicle traffic was off limits to people using the Park. They even landed helicopters to check our ID and make sure we where allowed to drive to his land on his easement. When the road started to erode, the Park arrested his son for fixing it, which lead to a court battle that he won. This happened over and over again. He was a local government employee and he enjoyed fighting with the Park, so these things happened all the time.

The biggest battle was when he "cleaned" up an old pond that was full of trees in a canyon near his cabin. Since the Park was not able to prove that the pond wasn't there before he "cleaned" it up and "rebuilt" the dam, they couldn't do anything about it.

If there was a bridge there previously, say 50 years ago, and it was in need of "repair", couldn't you just "rebuild" the bridge and not violate any of their rules?

Yes,
This was discussed with my friends in the know,, problem is in the age of aerial imagery,, previous years images show no bridge.

If I cross the creek in a responsible manner a dozen times a year with a permanent bridge to retrieve firewood/timber I have brocken many laws.
If I run my tractor up and down the creek bed for fun,, all is good.

 

[JPRambo]

My older brother was in the army. And when he was 'bored' he would go to the motor pool. He talked to the motor pool Sargent and tested and received a military driver's license to operate a mobile assault bridge in or around 1989 or 1990

 

[Slackdaddy]

Wonder if they'd have to inspect and permit this before each use?

The Army’s Newest Vehicle Is Actually a Heavy-Duty Bridge

The U.S. Army just finished operational testing of a new, mobile assault bridge, designed to cross battlefield barriers.

www.military.com

Dont laugh,
The creek is 30 yards from where the "forest goes up hill" and is no longer Non Tidal Wetlands,, I can do what ever I want there.
I was thinking about a light weight Alum trussed bridge of some sort,, I could get away with 5' wide x 11' long. just keep it 30 yards away, and pick it up and drop it over the creek when needed.

A lot of work for to just do some maintenance work for hunting, in the creek bottom.

 

[dodge man]

Have you seen the wetland maps? The entire concept is stupid in a lot of cases. It’s been over 20 years ago but we did surveying and engineering for a big box store all over the country. I did the surveying for one In Wisconsin that had a wetland specialist mark out the areas. Some areas were no bigger than 200 sq. ft. It appeared to me they were wetlands but some were man made by farming. They built the store but in one corner they had man made wetlands, twice as big as what was lost.

We had a potential lake project get shot down nearby because of wet lands. Can’t get wetter than a lake but I realize there is a difference between a lake and wet lands.

 

[2manyrocks]

Part of me wants to say to go ahead with the permitting process today because they'll find a way to make it even worse in the future.

 

[Slackdaddy]

Have you seen the wetland maps? The entire concept is stupid in a lot of cases. It’s been over 20 years ago but we did surveying and engineering for a big box store all over the country. I did the surveying for one In Wisconsin that had a wetland specialist mark out the areas. Some areas were no bigger than 200 sq. ft. It appeared to me they were wetlands but some were man made by farming. They built the store but in one corner they had man made wetlands, twice as big as what was lost.

We had a potential lake project get shot down nearby because of wet lands. Can’t get wetter than a lake but I realize there is a difference between a lake and wet lands.

Yes, USFW wetlands mapper shows the entire creek bottom is wetlands,, BUT USFW is a broad generalization. The state considers is wetlands, Until you have an actual survey that delineates an area (shows that it is NOT in fact wetlands, based on 2 of the 3 criteria being negative.

 

[Slackdaddy]

Well,
Spent some time with a wetlands expert.
I did soil samples - No wet lands soil types,, No water 18" down, and vegetation is not wetlands.
Some am I good to go ??
NOPE,, even though it is not wet lands I would have to do extensive "studies" totaling about $50,000.00 before being "allowed" to build a permanent bridge.

It kills me to see hundreds of you tube videos of guys building tractor bridges across creeks in "Free" states.

 

[chim]

Here's the bridge to our place. The bore is 16' wall to wall inside and around 4' above the average water elevation. I told the engineer it needed to be strong enough for fire trucks / dump trucks. I'd have to check the old drawings for good dimensions, but IIRC the footers are 9-ish feet down, walls are a foot thick, deck is 10" or a foot and the sidewalls stand about 6" above the deck.

The property is a piece my FIL sliced off a farm, and it took 3 years of dealing with red tape between the time he said he'd sell us the land till we "bent" ground. Start was too slow to say we "broke" ground The creek had a large U bend that ran from the other side of the bridge in the picture to about 50' behind where the camera was for the picture. The engineer calculated that building the bridge in the flood plain and eliminating the U bend cancelled out. He had to work with runoff figures far a rather large area of land. The process was started around 1986 and although I can't recall the cost, it wasn't cheap. The bridge itself wasn't very expensive. The GC we used for the house did it as a change order for less than 4 grand. I was going to build the bridge myself, and even got a quote on the rebar, but with such a bargain price - plus I was doing the electrical, plumbing, HVAC, central sucuum, etc - it was nice not having that to deal with.

 

[Bronco82]

...Not really knowing how to make this work on pure dirt, I'm going to shut up and hope someone who actually knows what they are doing will offer some suggestions.

That's a wise decision right there, nicely put. Self-awareness is an important quality!!

 

[Shblack]

I figured I would start a new thread for how to design/build an abutment,, as my other thread was about beam sizing.

So, my creek runs through a bottom that is about 100 yards wide and absolutely flat.
View attachment 789360

The soil is silty clay,, problem is when I put in a foot bridge 10 years ago, I concreted the post in about 1.5' back from the bank,, but over the years the bank has washed away, exposing the footer.
View attachment 789367

So, I will be putting my Tractor bridge in upstream about 100 yards,
The 2x4 in the picture is 12 feet long,, and has 1 and 2 foot marks on each end (black lines)
The water is somewhat low for this time of the year, but gets a few inches lower mid/end of summer.
One summer it did dryout,, and most spring/summer it over flows it's banks once or twice, putting a foot or so of water across the whole bottom.




View attachment 789368View attachment 789369

View attachment 789370


Any Ideas on Abutments? I am very skilled in Masonry and structural concrete.
I was thinking trying to dig down even with the bottom of the stream (even with the top of the bank) and pouring a footer about as high as the water is now,, (this would be easier if the water goes down come late summer.)
Then forming and pouring a abutment wall on the footer.

Other idea was to get some used "sheet Piling" about 4' long and driving it down just below the lowest part of the stream bed, digging out behind it about 2' back, and back filling with concrete and stone.
No mater what, I want the abutment to abutment distance to be no tighter than the top of the stream bank,, I do not want it to be a constriction when the bottom floods.

Any ideas or words of wisdom??

Another point to consider is your creek photos show no riparian vegetation on the banks. With bare soil exposed the banks will continue to erode, costing you soil and silting up something down stream. One technique to address this is to plant willows along the banks. If you can find some willows, cut short sections of branches and shove them into wet soil, nature will do the rest.