Two U shaped retaining walls

[ernestaschomicius]

Hi All,

So i'm a junior structural engineer (finished 2 years of uni part of civil engineering BEng course currently on my gap year) and I've been tasked with designing two retaining walls.

Details about retaining walls:

wall 1 has a U shape and has side walls of height 1m each and a span of 2m between them. As far as i'm aware they are going to be used to store pipes/cables in them. I need to design them to take a 45T truck to go either on top of them or next to them. I will also need to design some sort of steel plate to go over them that has holes or gaps for easy access. So my question is, how do i design them for this? do i split them both up in symmetrical shapes and toe them or design as one wall?? I do not have soil investigation for the site so my boss told me to use prety bad soil for this (roughly 17-22kN/m3 strength and angle between 35-40) I will be using Design of Structural Elements (3rd edition) books calculations so if you're familiar with it then let me know where to look.

My 2nd wall is similar but 1 side is 1m high and the other is 1.5m and 2m apart with a base. same questions apply.


Just to let you know I have no restricting factors to make this work so anything goes as long as they stick to those measurements.

Please help, I've designed retaining walls before but i am not sure how to even approach this u shaped wall.

[Cake of Doom]

Do you have a sketch of the proposals? It's quite hard to visualise on dims and weights alone.

[ernestaschomicius]

Here are some diagrams

[Cake of Doom]

If you're planning on hand calc-ing this, for simplicity I'd treat each wall as an individual cantilever using 1.0 m as toe. I'd also place the truck as near to the wall to see what effect the surcharge has at varying distances. Just be mindful of the forces acting on the centre of the slab. I'd design the back wall for bending only and use the side walls to prop it, that should help to cut down on unneeded materials. If you have an analysis program handy, do it as a single unit. I take the sole pressure assumption is for dry/drained soil? If its not clear, check with your boss as this will increase your factors.

[ernestaschomicius]

If you're planning on hand calc-ing this, for simplicity I'd treat each wall as an individual cantilever using 1.0 m as toe. I'd also place the truck as near to the wall to see what effect the surcharge has at varying distances. Just be mindful of the forces acting on the centre of the slab. I'd design the back wall for bending only and use the side walls to prop it, that should help to cut down on unneeded materials. If you have an analysis program handy, do it as a single unit. I take the sole pressure assumption is for dry/drained soil? If its not clear, check with your boss as this will increase your factors.

Thank you for the advice.

What are good software to use to model this on? I currently have tekla structures v21.0, could that be used to do this? My colleague has tekla tedds also so i could use that.

[Cake of Doom]

Tekla can do it. Software differs from company to company so just go with what you have to hand. Hunting down recommended software can take longer than doing the job by hand.

[cognitionkdhrng]

I was wondering whether you have a sketch of the proposals?