Whats being fenced in a prison or a scrap-yard?
Retaining Wall
- Thread starter antsals
- Start date
Sponsored Links
You need to take earth pressure, water pressure, and surcharge load for surface loads applied to the retained soil. Assume the earth and water load the wall with a 45 degree triangle of load, and the earth load is further reduced by its angle of friction (usually around 30 degrees). Best to assume a worst case of non cohesive soil (gravel).
Once you've done that you can work out the moment to the wall, and design it to resist that moment.
Then you should check bearing pressure (axial load to base plus pressure induced by the moment.) Should usually be limited to around 100kN/m2 maximum.
Then check overturning by assuming it will rotate about the front of the footing due to the moment. But the self weight of the wall and any other load directly over the footing will resist overturning. A factor of safety of at least 2 is usually assumed.
Then you should check for sliding. You've got the horizontal loads from the applied pressures resisted by the axial load to the footing. A frictional coefficient of 0.4 is about right.
It would be difficult to calculate the effect of the horseshoe by hand but it will definitely help.
I would think 12mm bars at 200mm crs would be sufficient for a 1340 high wall, and I'm sure Tony's 1m long base would be enough, but if you do want to try the calc I can send you an example.
You were still well stung for what you've ended up with. Not very pretty if you don't mind me saying so.
I could have shuttered that with peri for £5k including concrete and steel.
And you'd have something professional to look at for the rest of your days.
I wonder what you deem a "standard retaining wall"?
Standard to me is poured 35 newton concrete with a high quality smooth finish.
I handle shuttering like fine furniture. Anyone who scrapes it or throws it about carelessely gets a right rollicking as thats the same as damaging the customers wall. Until it goes to the repair shop of course or have time on site to do the repair.
Sponsored Links
You need to take earth pressure, water pressure, and surcharge load for surface loads applied to the retained soil. Assume the earth and water load the wall with a 45 degree triangle of load, and the earth load is further reduced by its angle of friction (usually around 30 degrees). Best to assume a worst case of non cohesive soil (gravel).
Once you've done that you can work out the moment to the wall, and design it to resist that moment.
Then you should check bearing pressure (axial load to base plus pressure induced by the moment.) Should usually be limited to around 100kN/m2 maximum.
Then check overturning by assuming it will rotate about the front of the footing due to the moment. But the self weight of the wall and any other load directly over the footing will resist overturning. A factor of safety of at least 2 is usually assumed.
Then you should check for sliding. You've got the horizontal loads from the applied pressures resisted by the axial load to the footing. A frictional coefficient of 0.4 is about right.
It would be difficult to calculate the effect of the horseshoe by hand but it will definitely help.
I would think 12mm bars at 200mm crs would be sufficient for a 1340 high wall, and I'm sure Tony's 1m long base would be enough, but if you do want to try the calc I can send you an example.
Please send an example it well worth knowing for the future. I did some level checks the other night wall needs too be 900mm high and the ground is clay. When I dig I can hardly shovel it cause it comes out in big lumps. I have to hand ball into the wheel barrow!
I really like the gabion idea as its a little "softer" on the garden. But filled with stone. So it would be 1m high made up made up of two 500mm high baskets, 500mm deep. As the design spec for gabions it would lean towards the soil on the 6 degrees. Gravel behind with drainage.
All I want to be able to do is confirm that would be adequate.
Thanks,
Ant
Friend request me and I'll email it to you, althoug at 900mm high in clay they are usually not designed, and it's just ensured that the depth is 4 x the height and the foundation is adequate.
Behind the fence is our raised lawn area which is accessed from the house with steps leading down to this lower level. Where the brick section is the center panel will be lifted out and we will then walk off the lawn directly onto the top of the workshop which is yet to be built in the lower.section. Giving us a upper decked area ot around 30 sq meters.
No need for a SE as all yhe calculations are on line.
Hope this helps
Jon
you could always add a few buttresses, they add incredible strength to a wall, but nobody seems to want to them any more, its all rebar and concrete these days
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
