Project description: construction of four bedroom duplex and two unit of two bedroom flat on a single plot of land @ isheri opic estate
Name of contractor : Abdulwastecx
Duration of project : 6months
Client : A nairalander.

We will start off by thanking God almighty and Nairalanders ( Mr Qc1 for his referral and the client for his trust in our ability and integrity) for making this project possible. I thank you sirs.

Scope include the design and construction of this building. The design was carried out by Harney projects and the construction will also be done by Harney project. The client hired an independent firm to carry out the soil test based on the recommendation of our team on ground after site visitation

Site visitation: We visited the site December, 2016 to have a first hand information about the nature of the site before work can commence

abdulwastecx:
Site visitation: We visited the site December, 2016 to have a first hand information about the nature of the site before work can commence

This is a big project..Congratulations! Show us what you got on this one...

The level of surface water was so high that we had to recommend immediate filling of the access road and the use of sand to demarcate the site perimeter so that we can pump out the excess water before a soil test can be carried out .This prompted our visit to the nearest sand fill to check a suitable and cost effective soil to use for the filling of the access. In this case, soil with considerable sharp sand locally called "yoyyo"

The access road was filled, site demarcated and excess water pumped out in other to carry out the soil test by a geotechnical nominated by the client. At this point we were waiting for the result of the soil test to conclude the foundation design

Construction of perimeter fence :
Q perimeter fence measuring 30m, 30m and 18m is to be constructed around the site to finally isolate the ground water for easier site dewatering.

The grade beam/raft beam is 1.2m

Dominionng? Present!

Congrats boss

topsy23:
Congrats boss

Thanks boss

Fence beam brief description : before embarking on the fence beam construction we had to do some due diligence by going round the estate to investigate other similar fence built in addition to the result of our soil test report.

Here is what we have

Oga mi, welcome to Lagos, it's a different ball game here.

Congratulations Sir.

More pictures

Happy to be part of this laudable project, Weldone a good job, God bless ur hustle. IJN, Amen

Welcome to the real Capital of Nigeria.

Hajji M.

My able engineer. Congrats, and success are my wishes.



Well done!

congratulations.....Nice job done..
meanwhile, with regards to landscaping and beautifications...
check my profile..
we add values to your real estate property..
cheers

More fence bean work

Fence block work

To the main building: here is what we have in mind

On the ground floor we have the following
Duplex side
1. Living room
2. Dining
3. Kitchen
4. Visitor's bedroom
5. Store
4. Visitor's toilet
5.General toilet

Two bedroom flat side
1. Living room
2. Dining area
3. Kitchen
4. two bedrooms with one en suit toilet and one open toilet

Stage one: Removal of all organic materials and soft soil strata up to a depth of 500mm

This involved the removal of all organic decay materials (vegetation) on the surface and all the soft clay up a considerable depth below where hard soil strata can be found.

The operation was carried out as follows
1. we mark out the external perimeter of the site with an allowance of 2m by all the four side.
2. We divided the work into 4 part and employed manual removal using ten labor
3. After removal we carted away loose soil to nearest by site
4. Finally, dewatering operation of the site was carried out

More

Stage 2: setting out
This involves transferring of information on the designs (structural and architectural design) onto the ground so that construction work can be carried out.

Here, we are going to be using profile board for our setting out.
Materials includes the following.
1.pegs
2. 2 x 2 as profile board.
3. nail.
4. Builder's rope.
5. Builder's square.
6. Claw hammer.
7. Meter rule
8 water level.

Did you come across snakes while working on this water-logged land? This is type of area where pythons hide.

Stage three foundation work: The foundation type is near surface raft foundation
Raft foundation was employed based on the recommendation of the Geo technical soil report, prevailing site condition and foundation type of all the surrounding similar structures. An extensive investigation was carried out to know the foundation type of surrounding structure and it was observed that all the building in the estate were built on a near surface raft foundation.

I will start by defining what is a raft in a simple language: A raft foundation is a type of shallow foundation also known as mat foundation which is use when the bearing capacity is low in respect to the anticipated dead and the life load that the building is expected to carry, it covers the entire area of the foundation and help to distribute load uniformly thereby help to counter the effect of differential settlement in expansive clay.

We have the following type of raft foundation
1. flat slab raft
2. slab-beam raft

lab beam raft is further divided into
1. Up stand beam raft
2. Down stand beam raft
3. Cellular raft.

Analysis can be done rigid method or flexible method. The analysis is carried out using this simplified method.
1. estimation of floor loading intensity: floor loading intensity is the total load of the super structures coming to the foundation. In the case of a frame building it is equals to load coming through all the columns divided by the area of the foundation. for this particular project, the floor loading intensity was estimated to be 16kN/m2

2. Compare the loading intensity to the safe bearing capacity of the soil. safe bearing capacity= ultimate bearing capacity/ Factor of safety. If the loading intensity is lower than the safe bearing bearing capacity the raft foundation design can be carried out, otherwise the foundation area is increase

3. Estimation of the center of of area of foundation and center of gravity of load. If center of gravity of load doesn't correspond to that area, the corresponding eccentricity along x and y-axis are estimated.

4. application of the soil bearing pressure to the slab and designing of the slab like a suspended slab using coefficient in BS 8110 for two way slab or using manual analysis like a continuous beam for a one way slab. Note, unlike normal suspended slab load on raft foundation slab act upward not downward and the resorting bending moments are opposite to that of a suspended solid slab.

5. Design of slab like normal suspended slab

6. load from the slab are transferred to the beams and the beams are design like normal suspended beams.

7. checks are carried out for immediate settlement, secondary settlement and consolidation settlement using a soil profile (bore hole test is important here).

Some misconception about raft foundation.
1. So many people don't pay too much attentions to the raft slab by wrongly assuming that the beam is the foundation. The beam is a component of a raft slab but the slab is the main load distributor to the supporting soil, the beam help to reduce excessive shear stress along the critical perimeter of columns because of the magnitude of point load carried by the columns

2. the depth of the beam of a raft foundation is not governed by the safe bearing capacity but by the magnitude of load transfer from the slab it support and magnitude of shear force at column point

FastShipping:
Did you come across snakes while working on this water-logged land? This is type of area where pythons hide.

We didn't come across any snake, the site is already built up

For this project the depth dimension of the raft beam is 250 x 1800mm
while the depth of the slab is between 175mm to 200mm

Foundation work

1. excavation of foundation trenches : excavation work was carried out to have a uniform base point before applying a blinding of about 150mm to 200mm

Foundation blinding