Retaining walls are structures used in providing stability for earth or materials where conditions do not give room for the material to assume its natural slope and are mostly used to hold back soil banks, coal or over, piles and water.
Retaining walls are distinguished from aone another based on the method of achieving stability.
There are six type of retaining walls and are:
i.    The gravity wall
ii.    The cantilever wall
iii.    The counterfort retaining wall
iv.    Buttressed retaining wall
v.    The crib walls
vi.    Semi-gravity wall
Bridge abutments are often retaining walls with using wall extension to retain the approach fill and provide protection against erosion. They differ in two major respect from the usual retaining walls.
i.    They carry and reactions from the bridge span.
ii.    They are restrained at the top so that on active earth pressure is unlikely to develop.
Foundation walls of building mduding residential construction and retaining walls, whose function is to contain the earth of the basement.
Retaining walls are required to be of adequate proportion to resist over turning and sliding as wall as being structurally  a proportion to resist over turning and sliding as wall as being structurally adequate.
Terms used in retaining wall design are shown below (f.g 1-2)
The toe is both the front base perfection and forward edge, similarly for the heel the backward perfection.

TABLE CONTENTS

Preface
Dedication
Acknowledgement
Introduction
Notations used

CHAPTER ONE
Introduction
Retaining walls
Cantilever rw
Rankin theory
Forces on cantilever rw
Counterfort  rw
Forces on counterfort rw
The gravity rw
Forces on gravity rw
Semi gravity rw

CHAPTER TWO
Stability of retaining wall
Soil properties of rws
Drainage in rw
Allowable bearing capacity

CHAPTER THREE
Procedure for the design of rw
Cantilever rw
Analysis example

CHAPTER FOUR
Design of retaining wall
Conclusion

REFERENCES

NOTATION USED IN THIS PROJECT
1.    Angle of internal friction of soil        -            O
2.    Unit weight of sol                -&
3.    Sat unit wt        -    &sat
4.    sauntered unit wt        - &sub
5.    Overturning moment    -    Mo
6.    Base width of container wall     -    B
7.    Overall height of wall     -    H
8.    Effective height of wall    -    He
9.    Height of stem    -    h
10.    Effective depth    -    d
11.    Overall depth    -    d
12.    Weight stem        -    we
13-    Weight soil        -    ws
14.    Surcharge        -    S
15.    Active pressure on wall    Pa
16.    Passive pressure on wall    Pp
17.    Breadth for design    -    
18.    Sum of vertical weight        -    Ew
19.    Point of application of the resultant    X
20.    Eccentricity                -    e
21.    Sum of moments            -    Em
22.    Characteristic strength steel    -    fy
23.    â€œ    â€œ    â€˜    concrete    -    fcn
24.    Lever are factor            -    z
25.    Lever are                    Z
26.    Ultimate shear stress        -    Vc
27.    Shear force                -    V
28.    Shear stress.                -    v