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CHAPTER 0NE
INTRODUCTION
A foundation (also called a ground sill) is a structure that transfer loads to
the earth. The footing plays a specific load- bearing roles in as much as they
support the weight of the building. Whether the building rest on post or walls
which in turn rest on the footing. In planning footings be sure to consider the
types of soil in which they will be poured (clay, marshy etc.) At the very
least, footing must be poured below the frost line.
Foundations are generally broken into two categories; shallow foundationand deep foundation.
Shallow foundation is, usually, embedded a meter or so into soil. One
common type is the spread footing which consist of strip or pad of concrete
(or other material) which extends below the frost line and transfer the weight
from wall and columns to the soil or bedrock. Another common type is the
slab-on-grade foundation where the weight of the building is transferred to
the soil through a concrete slab place at the surface.
Deep foundation is used to transfer a load from a structure through an upper
weak layer of soil to a stronger deeper layer of soil. There are different types
of deep foundations including helical piles, impacts, caissons, pier, and earth
stabilized columns. The naming conventions for different types of
foundations vary between different engineers. Historically, piles were wood,
later steel, reinforced concrete, and pre-tensioned concrete.
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PURPOSE OF STUDY
AIM
The primary aim of this study is to produce the working activities,time and cost of the foundation of a given house plan.
OBJECTIVES
To identify the approach to foundation production.To determine suitable time it takes to excavate foundation trenches
To determine the cost it take to excavate the foundation trench
STATEMENT OF PROBLEMSThis case-study is design to know appropriate / correct procedure to
follow in the undertaking of any substructure
SIGNIFICANCE OF STUDY
This study will help the reader to understand a way to forecastfoundation production activities, that is involved in any given house
plan. Also the considerations to put in place as to the difficulties that
may be encountered.
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METHODOLOGY
The following procedure among other things has been the method that
will be employed to carry out this study:
Site clearance and setting out of the house plane Excavation of the trench and pouring of concrete footings Laying of foundation block wall and backfilling. Setting the formwork, filling hardcore and over site concrete
SCOPE AND LIMITATION
The study focuses only on the assessment of foundation activities of
the two bedroom bungalow plan. It determines the time and cost
involved in the sub-structure.
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CHAPTER TWO
LITERATUE REVIEWFoundation is the most essential part of structure of any
building. The concrete footing most rest on firm soil
and extend below frost line. Build footing on lightly
moist soil (be sure that soil is not wet). National and
local building codes indicate footing depth; ask your
local building department.
Flat surface footing is used when the foundation wall is madeof concrete block or cast concrete. It is possible to make a
grove in the footing to hold the foundation concrete. Just
insert the edge of a 2x4 on top of the footing and remove as
the concrete has hardened.
Pier foundation(12diam) is used as foundation or footing orfooting without any other support. They are evenly spread
around the building perimeter according to the local building
codes. Dig a hole to install the sonotube and fill with
concrete.
Excavation and formworkExcavation; place stakes to indicate footing area. Removing
line from batter boards. Keep the area free from debris and
dirt.
Formwork; headed nail are easier to remove than ordinary
nails. Nail them into the stakes down to the formwork. Oil
formwork surface touching concrete with waste crank-case
oil.
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Foundation tiesmetal or plastic wires that hold thefoundation panels and rebar in place while concrete is being
poured.
Gradeground level or elevation at any given point.Excavation or buildings foundation. Correct grading cause
water to drain away from the buildings foundation.
Causes of foundation failureMany houses are constructed with foundations that are
inadequate for the soil condition existing on the site. Because
of the lack of suitable land, houses are often built on marginalland that has insufficient bearing capacity to support the
substantial weight of a structure. In addition, there are many
areas of the country where the near surface soils consist
predominantly of expansive clay that shrink and swell as their
moisture content changes. If the bearing soil consist of
expansive clay, foundation movement can occur uniformly
across the entire slab. Any of the following can cause
moisture in the soil to fluctuate vegetation (roots), poor
drainage, plumbing leaks, evaporation, and wet/dry rain
cycles.
Slab-on-grade foundation depends upon the upper-most soil
layers to provide sufficient bearing capacity to support the
structure and keep the foundation stable. If the bearing soil
was insufficiently compacted prior to construction, thefoundation is subject to settlement as the supporting soil
consolidates.
Symptoms of foundation failureThe sign of foundation failure do not become obvious until
after there are serious problems with the foundation. The most
obvious sign will be door that do not close properly anymore,
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windows that stick and diagnosis crack in the interior and
exterior wall. Less obvious symptoms are small cracks in the
foundation or floor and uneven floors. Sixty percent of all
houses built on expansive soils suffer from foundationdistress. The problem occurs when only part of the foundation
leans or settles, causing cracks and other damage. This
differential movement is largely caused by differences in soil
moisture. Loss or gain of soil moisture can cause serious
shrinkage or swelling.
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CHAPTER THREE
METHODOLOGYThis aspect of the work will describe the complete activities
that are to be undergone. The house plane is shown below.
The production activity will include the time and cost.
TAKE OFF SHEET
SUB-STRUCTERE ACTIVITIES
1. Site clearance2. Setting out3. Excavation of trench4. Foundation concrete footing5. Foundation block work6. Backfilling & compaction7. Hardcore filling8. Formwork9. Over site concrete
1. Site clearance
Removal of top soil not exceeding 300mm deep and cart away with trust
from site.
Length - 11.87Add - 3.00 14.87 x 14.24 = 212.5m
2
14.87
Width - 11.24
Add - 3.00
14.24
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2. Setting out
External girth - 46.2m2
Internal (horizontal) - 20.08m2
Internal (vertical) - 20.70m2
Total - 86.98m2
3. Excavation of trench
Girth
External girth - 2 x 11.9 = 23.8m
2 x 11.2 = 22.4m
46.2m
Internal girth - 20.08m
Vertical - 20.70m
Total girth - 46.2m
23.8m
+ 22.4m
86.98
Length - 86.98m
Width of trench - 0.68m 53.23m3
Depth of trench - 0.90m
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4. Foundation footing
0.68
0.90
0.15
Length - 86.98m
Width - 0.68m 8.87m3
Depth - 0.15m
5. Foundation block work
0.90 0.75
0.15
0.68
Length of block- 85.98m
Height of block - 0.75m65.24m
2
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6. Back filling
0.30m
0.68
Length -11.90m
Width - 11.20m 39.98m3
Depth of backfilling - 0.30m
7. Hard core
0.30
0.30
0.68m
Length -11.90m
Width - 11.20m 39.98m3
Depth of hard core - 0.30m
Earth filling
Hard core
Earth fill
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8. Form work
Sawn timber plank to both side of the top.
2 x 11.90 =23.8m
2 x 11.20 =22.4m
46.2m
Length of timber plank = 46.2m
Width of timber plank = 0.25m
9. over site concrete
Concrete of 1:2:4 -20mm aggregate well compacted, place to avoid
segrement of concrete
0.15m
0.30m
0.30m
0.15
Length -11.90m
Width - 11.20m 19.9m3
Depth of concrete0.15m
Hard core
Earth filing
11.55m2
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WORK FORCE AND TIME
Site clearance
From table, Grader capacity 10,000m
2
/day
Site area to clear = 212.5m2
Therefore, 1day is required (1 operator, 1 banks man)
Setting out
Requires 1 day (1 engineer, 1 labour)
Excavation of trench
Maximum depth not exceeding 0.9m, requires 2.20hr/labour/m2
Therefore, 53.23m3
x 2.20hr/labour/m2
= 117.10hr
Work hour of labour/day = 8hr
1178 =14.63, approximately15 days for one unskilled labour.
155 = 3, 5 unskilled labour will excavate trench for 3 days
Foundation footing
Foundation concrete footing of 150-300 thick, requires 4.30hr/m2for
1 unskilled labour.
8.87m3
x 4.30hr/m2
=38.14hr
Work hour of labour/day = 8hr
38.148 = 4.76, approximately 5days for one mason and 1 unskilled
labour.
2 labourers, 2 masons will complete concrete footing in 2 days.
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Foundation block work
230mm hollow sandcrete block joint with mortar of 1:3 requires
1mason and 1labour for 10m2of block/day.
Total area of block work = 65.24m2
65.2410 = 6.52, approximately 6 days for 1 mason and 1 labour
62 =3, 2 mason and 2 labourers will complete block work for 3 days
Back fillings
Required 1.5hr/m
3
39.98m
3x 1.50 =59.97hr
8hr required/day for 1 labour
59.978 =7.49, approximately 8 days for 1 labour
84 =2, 4 labourers will complete back filling for 2days
Hard core
Ditto
Form work
0.45hr/m2
11.55m2
x 0.45hr = 5.1975hrs
Work hour of labour/day = 8hr
Requires 1 carpenter and 1labour to complete form work
Over site concrete
2.50hr/m3
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FOUNDATION PRODUCTION ACTIVITES TABLE
Task name Area(m
2)
Volume(m
3)
Hours ofwork (hr)
Requiresday of wk
Cost(N)
Site
clearance 212 3 1 25,000
Setting out
59.5 4 1 1000
Excavation
of trench 53.2 117 3 15000
foundation
footing 8.87 38 2
10000
Foundation
block work 65.2 52 3 15000
Back filling
&
compaction
39.98 59 2 8000
Hard core 39.98 60 2 8000
Form work 11.55 5 1 2500
Over site
concrete 199 50 1 9000
Total 16 days 73,500
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0
0.5
1
1.5
2
2.5
3
3.5
Numberofdays
Task Name
Graph of Task against Number of days
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0
5,000
10,000
15,000
20,000
25,000
30,000
Cost(Naira)
Task name
Graph of Cost against Task
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CHAPTER FOUR
SUMMARY OF FINDINGS
From the research findings, it can be deduced that the use of glass building is
quite economical provided aesthetics is also considered.
REFERENCE
Adeshoga, I. E (2002) glass as a structural material, Longman Lagos
Mechanical properties glass by R K Brow
Horst Scholze: "Glass - Nature, Structure, and Properties"; Springer, 1991, ISBN
0-387-97396-6
Steve W. Martin, Ph.D., Professor of Materials Science and Engineering,
Iowa State University.
R. W. Douglas: A history of glassmaking, G T Foulis & Co Ltd, Henley-
on-Thames, 1972, ISBN 0854291172
BY OJO EMMANUEL
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