Any civil engineers here? Wall for backfilling dirt

[Texashiker]

I have a previous thread about an eroding creek bank, which helped point me to this solution.

On the edge of the bank I am going with riprap, or just otherwise heavy rough rocks found in the local area. I am looking at lining a section of the creek bank with rocks heavy enough for 2 men to pick up.

The next phase is shoring up the eroded section of the property.

The solution I am looking at is a 4x6 by 10 foot long treated lumber. Set 4 feet into the ground, then stack cross ties on the inside. Space the uprights 8 feet center to center, as cross ties are 8 feet long.

Backfill with rip-rap (rubble) along the bottom edge of the wall, then backfill with dirt.

The first problem I need to address is cross ties rot. Even though they are treated, they still rot. The rotting of the cross ties is one reason why I want riprap against them.

Suggestions or ways to improve this?

OPTION 2

See post 22 of this thread for description

 

[jupiter57]

Saturate the ties with Linseed Oil.
That will repel water & make them last as long as you live.

 

[edro]

Aren't railroad ties already soaked in a turpentine/creosote type solution?

 

[Texashiker]

Aren't railroad ties already soaked in a turpentine/creosote type solution?

Yes, but they still rot after a few decades.

 

[runzwithsizorz]

Saturate the ties with Linseed Oil.
That will repel water & make them last as long as you live.

Providing the OP only lives for 8, or 10 years. Yo Tex, do not, I repeat, DO NOT!!! use wood for anything other than ornamentation!!!
As a landscape contractor, I built several walls back in the 70's, and 80's with railroad ties, and treated landscape timber using every trick in the book to insure they would last, (pea gravel, dual french drains, tar paper, re-bar, dead-mans, even had a license to buy creosote), and sadly, none of these structures have *truly* survived, and it breaks my heart. There are other more permanent ways to address your needs.

 

[Greenman]

How far out of the grade will the top of the wall be?
How far is it from the base of the posts to the slope?

Just offhand, 10' posts 4' deep looks like your wall is going to be 6' above grade, that's probably not going to work. Posts 8' on center is too far apart. 4' is what you want. You can extend post life by dipping them in tar. On the wall, put a layer of 30lb felt on the back side, install a drain pipe and back fill with gravel.

A concrete wall is going to be your best bet, second choice would be a gravity wall, but both will cost a whole lot more than wood.

 

[BigBarney]

that's a LOT of pressure for those railroad ties to hold back...

and good luck keeping the backfilled dirt from eroding through the ties when rains come.

any thoughts on drainage, for when the backfill settles in random ways and begins creating minor ponds?

you also REALLY need to consult with local regulations as ANY modification to a natural water source is almost ALWAYS regulated by local laws.

 

[Texashiker]

that's a LOT of pressure for those railroad ties to hold back...

That is what the stacked rubble is for, to help distribute the weight of the dirt.

and good luck keeping the backfilled dirt from eroding through the ties when rains come.

any thoughts on drainage, for when the backfill settles in random ways and begins creating minor ponds?

You are thinking too far ahead, and that is already being addressed.

Fill in the eroded area, leave a slight slope, build a creek out of river rock to help prevent future erosion.

Awhile back I saw something like what I am dealing with home and garden HGTV, the program was about preventing erosion by building a rock creek.

you also REALLY need to consult with local regulations as ANY modification to a natural water source is almost ALWAYS regulated by local laws.

In Texas, if the water is on your property, you control it.

 

[Imp]

Can't touch this... All I'll say is that you need to be careful with your retaining wall. The backfill and any water pressure (especially if there's no drainage) will put a huge amount of stress on the wall.

 

[lxskllr]

If I had access to a lot of rocks, I'd build a stone wall and fill behind that. It would look much nicer also.

 

[PClark99]

Civil Engineer by degree though the last time I actually ever did any civil engineering was 20 yrs ago.

Instead of railroad ties you could just stack some gabions to make a retaining wall.

Then you don't need to worry about rotting wood ever.

http://www.google.com/search?q=gabi...QG_y4GABw&sqi=2&ved=0CGQQsAQ&biw=1280&bih=853

 

[Texashiker]

If I had access to a lot of rocks, I'd build a stone wall and fill behind that.

That is what I am trying to do, but without using cement.

If the wall gives way, I would like it to be of all natural composition. If some rocks fall into a creek, so what. If chunks of cement fall into a creek, it does not natural.

No nails, no bolts, no cement,,, just some vertical uprights, and beams laid in horizontal.

Civil Engineer by degree though the last time I actually ever did any civil engineering was 20 yrs ago.

Instead of railroad ties you could just stack some gabions to make a retaining wall.

Then you don't need to worry about rotting wood ever.

http://www.google.com/search?q=gabi...QG_y4GABw&sqi=2&ved=0CGQQsAQ&biw=1280&bih=853

Thank you.

Cattle panel might work. Its something like 1/8 galvanized welded wire and is 50 inches tall. I can get them from the local tractor supply store.

http://www.tractorsupply.com/feedlot-panels/feedlot-panel-cattle-16-ft-l-x-50-in-h-3502077

 

[BigBarney]

That is what I am trying to do, but without using cement.

If the wall gives way, I would like it to be of all natural composition. If some rocks fall into a creek, so what. If chunks of cement fall into a creek, it does not natural.

No nails, no bolts, no cement,,, just some vertical uprights, and beams laid in horizontal.

cement is fully natural... just a combination of natural things and water... unless you use rebar

 

[lxskllr]

That is what I am trying to do, but without using cement.

If the wall gives way, I would like it to be of all natural composition. If some rocks fall into a creek, so what. If chunks of cement fall into a creek, it does not natural.

No nails, no bolts, no cement,,, just some vertical uprights, and beams laid in horizontal.

I mean sans wood though; solely a stone wall. build it like a wedge angled away from the creek at the top, and build it thick. Think "dam" in construction. It would take a lot of stone, but if you have it, it would look nice, be completely natural, and you'll get one hell of a workout :^D

 

[roguerower]

First off, I would advise not using just cement as you won't get a lot of strength out of it, especially under tensile strain. Now CONCRETE on the other hand with some rebar in it would be a lot more useful...if you were to go down that route.

Gabion baskets would be your best bet as the problem with the wood ties is that the ground water pressure will end up pushing them over after a period of time.

FYI, the north wall for the building I'm putting up is backfilled soil on one side, office space on the other. The concrete footer is 10' wide and 4' thick on the soil side, the wall itself is 3' thick, and 3' wide, 4' thick on the office space side. Got one helluva cantilever on the soil side.

http://www.askthebuilder.com/retaining-walls-types/

 

[Imp]

cement is fully natural... just a combination of natural things and water... unless you use rebar

Aside from the cooking of a batch of materials at close to a thousand degrees celsius to get portland cement and being a very energy intensive/polluting process, ya, it's natural...


If you're not a fan of the raggedy gabion wall look, armor stone might work too.

 

[lxskllr]

I don't know how accurate your picture is, but I don't like the bare earth that's exposed between your two rubble piles. If it's sandy soil, and the water level gets to that height, you'll have scouring, and the upper bank will likely collapse.

 

[Texashiker]

I don't know how accurate your picture is, but I don't like the bare earth that's exposed between your two rubble piles. If it's sandy soil, and the water level gets to that height, you'll have scouring, and the upper bank will likely collapse.

You are correct.

Its maybe around three feet from the average water level to the top of the first bank.

I will have to fill that in with riprap to stop further erosion.

 

[Humpy]

If the picture is close to scale you are looking to establish a finished grade ~12' above the water level and ~4' horizontally from the waters edge?

I would recommend driving in some 30' long sections of interlocking steel piling and then backfilling. Of course, you would probably tell me to get bent after receiving the quote.

 

[Texashiker]

If the picture is close to scale you are looking to establish a finished grade ~12' above the water level and ~4' horizontally from the waters edge?

Pretty close, yea.

I would recommend driving in some 30' long sections of interlocking steel piling and then backfilling. Of course, you would probably tell me to get bent after receiving the quote.

Thank you, but I plan on doing this by hand and using hand tools.

I can not get tractors or anything else in to the bank, so I have no other choice.

 

[MagnusTheBrewer]

You can improve the design by adding anchors ie. a single railroad tie set parallel to each section setback and buried about 5 or 6 feet into the hill with a cable attached to a plate on the face of the retaining wall. this will prevent bowing and slipping due to water and any freezing. Speaking of water, you need to slope the ground and use landscape cloth to prevent mud from clogging the rubble fill.

 

[Texashiker]

You can improve the design by adding anchors ie. a single railroad tie set parallel to each section setback and buried about 5 or 6 feet into the hill with a cable attached to a plate on the face of the retaining wall. this will prevent bowing and slipping due to water and any freezing. Speaking of water, you need to slope the ground and use landscape cloth to prevent mud from clogging the rubble fill.

I like that idea, thank you.

I am checking with the local electric company about some used telephone poles instead of 4x6 treated timber.

But either way, I need to go an estimated 6 vertical feet. Once I get 3 or 4 feet up, lay down a horizontal beam, use galvanized cables, bolts and clamps to secure the beams together.

Finish backfilling.

I wonder if I could use cattle panel for the fist 50 inches, backfill with rock, lay down the horizontal beams on top of the rock, backfill.

 

[MagnusTheBrewer]

I like that idea, thank you.

I am checking with the local electric company about some used telephone poles instead of 4x6 treated timber.

But either way, I need to go an estimated 6 vertical feet. Once I get 3 or 4 feet up, lay down a horizontal beam, use galvanized cables, bolts and clamps to secure the beams together.

Finish backfilling.

I wonder if I could use cattle panel for the fist 50 inches, backfill with rock, lay down the horizontal beams on top of the rock, backfill.

6 feet is a LOT! This is just a rough estimate but, you're talking about 4 tons per section. In addition to sloping the ground you back fill with rubble, I would put pipe or weep holes at ground level through the retaining wall. Seriously, I believe you need a contractor with experience. I've built 4 or 5 retaining walls over the years and would hesitate to build a 6 foot one myself.

 

[D1gger]

That wall will be holding back a lot of weight. It will have to have proper drainage to relieve water pressure. I would look at something like a gabion wall instead.

Link

My company has built all kinds of retaining walls using lock blocks, gabions, mortared rock walls and stacked boulder walls. We will not install wooden retaining walls, as they simply won't stand up to the test of time, plus the wood preservatives may not be good for the creek when the leach out of the wood.

 

[Olikan]

i am studying civil enginner

oh...shit, imperial system and uncommon english words D:

too lazy to help