Sea water Intake basin

[SHBH]

hi,
I am working on this 40m x 20m x 15m deep concrete seawater intake structure in south America. Being new to this kind of structures,i need some suggestion on the temporary work requirement. One of the contractors has suggesten in his quotation that since sheet pile is not that common in this region, they would like to use slurry wall...!! Now what exactly is this. Apart from this what can be done for water tightness of this structure..External water proofing on walls & slabs including inter epoxy lining or coating the reinf bars itself will do...or changind the concret itself to resist chloride n suphate...
Would appreciate if someone can give info on this.

 

[COEngineeer]

shbh, you will have better luck on this forum321
Good luck!

 

[COEngineeer]

or forum311

 

[hokie66]

There are a few ways of constructing slurry walls, but in general they involve the following steps:
1. Excavate trench, filling with bentonite slurry (thence the name) as the soil is removed. The bentonite serves to support the sides of the excavation temporarily.
2. On completion of excavation, it is frequently necessary to replace contaminated bentonite with new mud placed by tremie, which displaces the first batch, which is then recycled.
3. Place reinforcement into bentonite.
4. Place concrete by tremie, displacing the bentonite.

Then, for your permanent work:
1. Excavate inside the slurry walls, providing tiebacks as required similar to sheet pile tiebacks (or some other form of bracing system).
2. Dewater as required.
3. Construct working slab.
4. Install waterproofing (or tanking, as it is called in some areas).
5. Construct base slab and walls, using plenty of cement in concrete and plenty of reinforcement.

The contractor who has "suggested" slurry wall in his quotation should be requested to explain his procedures. Construction of slurry walls is done by specialist piling contractors.

 

[SHBH]

thanks all of you...
was a good link and construction steps given are really useful to understand the kind of work involved.
But about the waterproofing is it worthwhile to galvanise rebars....or Tanking(on outside) and surface coating(on inside) on walls with limiting crack width design is sufficient enough.

 

[hokie66]

In my opinion, galvanizing the reinforcing steel is definitely worthwhile. Don't know about the surface coating on the inside if this is a waterproof coating, as generally the rule is that you don't waterproof both sides. One side will fail, and it won't be the back side which can't go anywhere. You may also may want to consider a cathodic protection system, but I can't give any advice in that regard.

Is this intake for a desalination plant?

 

[SHBH]

no, it is for a LNG plant....water will be used to convert LNG into NG.