Welcome to this thread.
I am a Structural Engineer registered with COREN. I have First and Second degrees in Civil/Structural Engineering and more than 15 years experience building hundreds of structures in Nigeria.

DESCRIPTION
The building located in Lekki to be built in a swamp full of natural ground water. The building has a ground floor, a Gallery and a 2nd floor. All can sit between 3,000 and 5000 persons depending on the sit arrangement. I have called it a 3000 Seater but we designed for worst case scenario to carry more than 5000. Infact even if 10,000 persons have space to squeeze themselves into the building, the Structural strength can carry them all plus some more.

Sand filling of the site is first step after the land acquisition.

Before the construction is commenced, we did several Structural analysis of the frame structure using different design softwares. So as to determine the various loads and moments and share forces acting at the members.

Further Structural analysis and design

Space booked

Fence

We carried out Soil test and investigation to be very sure of the capacity of weight the soil can bear and also to understand the soil strata underneath the site.
2 Standard Penetration Test (Borehole)
8 Dutch Cone Penetrometre Tests (DCPTs)
The site is 2 full plots

Soil test

Compaction of the soil to achieve near-zero voids of the soil.

Excavation of trenches.
And BLINDING

I did very wide footings to spread the incoming loads of the building. Pressure equals Force (F) divided by the Area (A).
P=F/A. So when you want to reduce the Pressure coming to the soil, you increase the Surface area. This is simple Engineering based on simple physics. Engineering is based on sound science

From the soil test results, I could either use short piles or 'long' beams. The cost for short piles are cheaper than the cost of deep beams. But clients always have dislike for piles. Most probably because piles have been made to appear costly. It's like giving a dog a bad name to hang it.
This is why me and a group of Geotechnical Engineers and Geologists had to form a Pile Construction company that builds piles that are less expensive than deep rafts.

So on this site, we opted to use DEEP RAFT with wide footings.

Keep it coming. Learnt something already.

deking:
Keep it coming. Learnt something already.

Thanks alot

Raft

Raft formwork

Raft completed

Sandfill of the foundation

Compaction of the sand to level

Roller compactor is very good in Compacting the sand to achieve near zero void.
When the sand is fully compacted, the ground flood slab will not require so much reinforcement again like a suspended floor slab will require.
But if it is not well compacted, then the ground floor slab will just be the one carrying itself. So it's better to design and construct it as a suspended slab. Or else you het failed slab with cracked tiles

Blinding for the Ground Floor Slab.

NOTE:
We covered the compacted sand with thick nylon to avoid flow of ground water to the building. Reason why some houses have walls and tiles that suffer moist effects

Rebar works for slab

Reinforcement

Casting of ground floor slab

Casting

No time to check time.
Blockwork done and dusted

I love using super strong concrete blocks that I produce. However I didnt use concrete blocks on this project
I will.use these blocks to build your own house. I mean YOU!

Blockwork

Carpenters are ready to start the columns (pillars)

Carpentry works

Carpentry