m 2008 Ceet 01 Ryoba Vuzimpundu Eugene Gs20031702

8/13/2019 m 2008 Ceet 01 Ryoba Vuzimpundu Eugene Gs20031702

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KIGALI INSTITUTE OF SCIENCE AND TECHNOLOGY

INSTITUT DES SCIENCES ET DE TECHNOLOGIE DE KIGALIAvenue de l'Arme, B.P. 3900 Kigali, Rwanda

FACULTY OF ENGINEERING

DEPARTMENT OF CIVIL ENGINEERING AND ENVIRONMENTAL TECHNOLOGY

A PROJECT REPORT

ON

DESIGN OF FLYOVER SUSPENDED PEDESTRIAN BRIDGE IN KIGALI

CITY

Submitted by

RYOBA VUZIMPUNDU Eugne(REG.NO: GS20031702)Under the Guidance of

Mr. NGARAMBE Andr

Submitted in partial fulfilment of the requirements for the award of

BACHELOR OF SCIENCE DEGREE IN

CIVIL ENGINEERING AND ENVIRONMENTAL TECHNOLOGY

FEBRUARY 2008

PROJECTID:CEET/07/3


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DECLARATION

I, RYOBA VUZIMPUNDU EUGENE declare that this project work is my own work

and has not been represented any were else, either Universities or any other Institutions

of high learning, for academic or any other purposes.

Signature ..

RYOBA Vuzimpundu Eugne


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DEDICATION

To my GOD, my family; my beloved parents, brothers and sisters, I dedicate this book;it is the fruit of your love and encouragement. I dedicate also this book to all survivors

of genocide of 1994 and NDAHAYO JULES who passed away in last year; we always

remember you.

You all, I love you.


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ACKNOWLEDGEMENTS

It was a deep sense of gratitude that I address my acknowledgements to my parent,

brother and sisters I am grateful to them, for having continuously supported me during

my studies till at present and tough me the value of life.

I am wholeheartedly indebted to my classmates, my friends, whose love, advices,

motivation and encouragement made me who I am now, and without whom this project

would ever have seen light of the day, this is the impatiently awaited fruit of their

endeavors.

I would like to express my heat-felt gratitude to KIST authorities, whose financial

supports and extraordinary effort made this project possible.

I thank my project guidance, Mr. Andre NGARAMBE, whose inspiring guidance and

innovative question have made this project a pleasurable learning and working

experience.

Many thanks whomever his assistance and advice, helped me to successfully complete

my project.


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ABSTRACT

The purpose of this bridge was to make the conception, the analysis and design of

flyover suspended pedestrian bridge in Kigali City. The following study was

completed with three phases. The first phase involved a deep investigation for the

bridge in which enough and relevant information were gathered from different area in

Kigali City.

Investigation did not only cover the site conditions, but also the availability of the local

materials as well as produced by the industries of our country of was used in second

phase of the project; this phase involved mainly the conception or the architectural

design of the bridge. At the end of the second phase, a steel structure was generated and

then in the last phase, subjected to the detailed structural analysis so as to obtain the

forces within the different component of the bridge. These former were used, in turn to

design the different component of the structure. In design, most of standards

specification and practice codes used were prepared.

Finally, detailed plans and drawing were prepared. The achievements of this study

reveal the possibility of improving condition of the mixed traffic by separating

pedestrians and vehicles.


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TABLE OF CONTENTS

DECLARATION ............................................................................................................... i

DEDICATION ................................................................................................................. ii

ACKNOWLEDGEMENTS ............................................................................................ iiiABSTRACT .................................................................................................................... iv

TABLE OF CONTENTS ................................................................................................. v

LIST OF FIGURES AND PHOTOS .............................................................................. vii1. FIGURES ............................................................................................................... vii

2. PHOTOS ................................................................................................................ viiiLIST OF TABLES .......................................................................................................... ix

LIST OF SYMBOLS, ABBREVIATIONS AND NOMENCLATURE .......................... x

CHAPTER 0.INTRODUCTION ...................................................................................... 10.1 GENERAL INTRODUCTION .............................................................................. 1

0.2 JUSTIFICATION OF THE PROJECT .................................................................. 2

0.3 GENERAL OBJECTIVES AND AIMS OF THE PROJECT ............................... 30.3.1 GENERAL OBJECTIVES .............................................................................. 30.3.2 AIM OF THE PROJECT ................................................................................. 4

0.4 SCOPE OF THE STUDY ...................................................................................... 4

0.5 SITE INVESTIGATION ........................................................................................ 60.6 PROBLEM FACED ............................................................................................... 6

0.7 TRAFFIC VOLUME STUDY ............................................................................... 8

0.8 DATA COLLECTION FROM TRAFFIC POLICE .............................................. 90.8.1 CAUSE OF ACCIDENTS INYEAR 2005-2006 .......................................... 10

0.8.2 HOUR ACCIDENT SURVEY IN YEAR 2005 AND 2006 ......................... 11

CHAP I. LITERATURE REVIEW .............................................................................. 12

1.1 INTRODUCTION TO SUSPENSION BRIDGES .............................................. 121.2 DESCRIPTION .................................................................................................... 12

1.3 THEORY ON SUSPENSION BRIDGE .............................................................. 14

1.4 TYPES OF SUSPENSION BRIDGES ................................................................ 15CHAP II. MATERIALS FOR CONSTRUCTING OF THE ......................................... 16

PROPOSED PROJECT .................................................................................................. 16

2.1 INTRODUCTION ON COMMONLY USED MATERIALS ............................. 162.2 TYPES OF SUSPENSION BRIDGE CABLES .................................................. 17

2.2.1 CABLE STRUCTURES ............................................................................... 17

2.2.2 TYPES OF WIRE CABLES ......................................................................... 182.3 REINFORCED CONCRETE MATERIAL ......................................................... 20

2.3.1 GENERAL INTRODUCTION ..................................................................... 202.3.2 CEMENT ....................................................................................................... 20

2.3.3 AGGREGATE ............................................................................................... 222.4 STRUCTURE OF WOOD ................................................................................... 23

2.4.1 GENERAL INTRODUCTION ..................................................................... 23

2.4.2 CLASSIFICATION OF TREES ................................................................... 232.5 COLUMNS ........................................................................................................... 23

2.5.1 INTRODUCTION ON COLUMNS .............................................................. 23


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2.4.2 CLASSIFICATION OF COLUMNS ............................................................ 24

2.6 FOUNDATION .................................................................................................... 242.6.1 GENERAL INTRODUCTION ...................................................................... 24

2.6.2 FOUNDATIONS AND THE EARTH .......................................................... 25

2.6.3 TYPES OF FOUNDATION .......................................................................... 25

2.7 BEARING CAPACITY OF SOIL ........................................................................ 262.8 LOADING ............................................................................................................ 26

2.8.1 DEAD LOADS .............................................................................................. 27

2.8.2 IMPOSED LOADS ........................................................................................ 272.8.3 DESIGN STRESS .......................................................................................... 27

CHAP III METHODOLOGY ......................................................................................... 28

CHAP IV DESIGN OF FLYOVER SUSPENDED PEDESTRIAN BRDGE ............... 294.1 DESIGN INFORMATION ................................................................................... 30

4.2 DESIGN THEORY ............................................................................................... 30

4.3 DESIGN OF MAIN CABLE DIAMETER .......................................................... 324.4 DESIGN OF TRUE LENGTH OF MAIN CABLES ........................................... 34

4.5 DESIGN OF TRANSVERSAL AND LONGITUDINAL BEAMS .................... 354.5.1 DESIGN OF TRANSVERSAL ..................................................................... 35

4.5.2 DESIGN LONGITUDINAL BEAMS ........................................................... 374.6 DESIGN OF SUSPENDERS CABLE DIAMETER ............................................ 39

4.7 DESIGN OF TOWERS ........................................................................................ 40

4.8 DESIGN OF FOUNDATION............................................................................... 414.9 DESIGN OF COLUMN BASE ............................................................................ 43

4.10 DESIGN OF STAIRS LONGITIDUNALY BEAMS ........................................ 45

4.11 DESIGN OF LATERAL BEAMS OF STAIRS ................................................. 474.12 DESIGN OF SUPPORT COLUMN OF STAIRS .............................................. 48

4.13 DESIGN OF FOUNDATION FOR COLUMNS OF STAIRS .......................... 494.14 DESIGN OF ANCHORAGE BLOCKS ............................................................. 50

4.15 DESIGN CONNECTIONS WITH BOLTS........................................................ 51

V. CONCLUSION AND RECOMMENDATION ......................................................... 525.1 CONCLUSION ..................................................................................................... 52

5.2 RECOMMENDATION ........................................................................................ 52

REFERENCES ............................................................................................................... 53

APPENDICES ................................................................................................................ 54


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LIST OF FIGURES AND PHOTOS

1. FIGURES

Figure 1: Parts of suspended bridgep13

Figure2: 1. Galvanized Bridge Wire...p17

Figure3: Parallel Wire Cable...p18

Figure 4: Detail of Main Cable and Cable Band.p18

Figure 5: Close-up view of Main Cable..p19

Figure 6: Cable with Clipp19

Figure 7: bridge span, loading and flesh.p31

Figure 8.1: load diagram.p33

Figure 8.2: loading diagram in lateral direction.p33

Figure 8.3: result of diagram cable.p35

Figure 9: transversal beam..p35

Figure 10: load, shear, moment...p36

Figure 11: load, shear and moment.....p38

Figure 12: suspender cable diameter...p39

Figure 13: load column....p40

Figure 14: column and beam dimension.p41

Figure 15: foundation..p42

Figure 16: Reinforcement in foundation.p43

Figure 17: bars in foundation..p43

Figure 18: base column ..p44

Figure 19: fixation and connection of base column.....p45

Figure 20: stair span.............................................................................p46

Figure 21: load, shear and moment..p48Figure 22: columnp49

Figure 23: anchor and fixation of cable...p50


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2. PHOTOS

Photo1: Mixture crossing of road of pedestrians and vehiclesp 11

Photo 2: big number of pedestriansp11

Photo 3: scope of the study..p14

Photo 4: big number of vehicles at the site of the study..p14

Photo 5: inattention of policemen, pedestrians, and driversp16

Photo 6: time west for crossing loadp16

Photo 7: Big volume of pedestrians crossing the Round about...p18


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LIST OF TABLES

Table 1: traffic volume survey; Round about Kigali city, Nyarugengep17

Table 2: percentage of death, injured and accident in Kigali city...p18

Table 3: causes of accidents in Kigali city..p 19

Table 4: Daily hour accidentp19


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LIST OF SYMBOLS, ABBREVIATIONS AND NOMENCLATURE

A cross sectional area

B beam width, foundation base

bf width of pad of foundation

cm centimeter

C span, width

FCV vertical component of force

FCH horizontal component of force

D diameter, depth

DW horizontal distance

DT vertical inclined distance

d effective depth

F axial Force

E modulus of elasticity

y deflection

fk characteristic of compressive strength of masonry

fck concrete characteristic strength

fyk reinforcement characteristic strength

g gram

I moment of inertia of area

k kilo

L length, length of span

l true length

LE effective length

M bending moment

Max maximum

Min minimum

m2 meter square

mm2

millimeter square

N Newton

Pc compressive strength of beam


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q Ground pressure under foundation

R reaction at the end

r radius of gyration

S plastic modulus

t beam web thickness

T tension

UDL uniformly distributed load

V shear force

v design shear stress

W magnitude of uniformly distributed load

w uniformly distributed load

WA weight of anchor block

angle

Stress

y yield stress

pi

Elongation


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CHAPTER 0.INTRODUCTION

DESIGN OF ECONOMIC FLYOVER SUSPENDED PEDESTRIAN BRIDGE

IN KIGALI CITY

0.1 GENERAL INTRODUCTION

The Kigali City, the now days facing traffic problems mainly due to the increase in the

number of vehicles, The increase is directly related to the parallel increase in population

number and based also on the vision plan of the Kigali City.

The traffic problems include traffic jams, which normally result in delays and

increase in load cost, accident which result in damage to vehicles as well as loss of

human lives.

It may be observed that most of accidents involving pedestrians occurs while

they crossing road of heavy vehicles, inattention or/and high speed traffic. Mean while,

quite number of solution has been worked out and implemented at different location of

interest within the City of Kigali; among this we can mention here, the use of traffic

policemen, traffic lights, speed ramps, zebra crossing and road signs. Some of these,

such as traffic lights (signals) and policemen or manual control and other measures

control and other previous performed ineffectively if not failed.

Therefore, based on the previous stated solution, my challenge in the prevent

project was to find out a new and better solution why not be best, using the modern

trend and technologies. The solution would be the permitting the smooth, safe, secure,

and smart passage of vehicles and pedestrians. While studying this problem of crossing

the roads, I thought the possible and effective solution would aim at separating the two

traffic component mean pedestrians and vehicles.

This implies directly prevision for a pedestrian path under above the road way.

However, further observation of how roads are constructed in Kigali City dictate thesolution of an economic flyover pedestrian bridge as the adequate solution.


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Photo1: Mixture crossing of road of pedestrians and vehicles in Kigali road.

0.2 JUSTIFICATION OF THE PROJECT

As here above mentioned, there is a problem of crossing roads certain particular places

in KIGALI CITY, where the traffic is heavy. There is proved or supported by findings

from accidents study made by traffic police office. The survey conducted by this office

shows the increase of big number of accident along with an increase in number of

vehicles. The cause of different accidents varies from an accident to another. Some are

due to the high speed of vehicles, bad driving, other to the violation of road codes,

either intentionally or not, on other hand, some of road users such as children, present

difficulties in crossing roads of heavy traffic.

However, the services in change took measures so in order to overcome this

problem. Different methods as mentioned in the introduction of this project are now

used but they are suffering from certain handicap, and sometimes create auxiliary


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0.3.2 AIM OF THE PROJECT

The main aim of the project can be follows:

Making conception, analysis, as well as design of an economic flyoversuspended pedestrian bridge in KIGALI CITY constructed by local materialsuch as metallic profiles, steel and wood etc.

0.4 SCOPE OF THE STUDY

The suitable site was selected based on the traffic volume mean for pedestrian and

vehicles where there is a big number of pedestrians crossing the roads, also the second

criteria was to find out the most difficult place to within Kigalis districts as well as

Nyarugenge, Kicuciro and Gasabo district.

Gitega (EPA)

Kanogo at TOTAL (ex-SOPETRAD) Payage (on boulevard de lOUA Kiyovu) Kimihurura (primarly school) Sainte famille church (round about) Round about (town center RUBANGURA) Remera Giporoso

The third criteria concerned the category of pedestrians facing problem such as children

going and coming from school, adult people going or coming from church and also

based on the accidents records from the traffic police office.

Gitega (EPA) Sainte famille (near round about town center) Kimihurura (primarily school) Round about (town center RUBANGURA in front of Ex-Nyira-Rock )

Finely, ROUND ABOUT town center (RUBANGURA) in front of near Nyira-Rock

was selected as the site thats the characteristics mentioned above.


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Photo 3: scope of the

study

Photo 4: big number of vehicles at the site of the study


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0.5 SITE INVESTIGATION

Before a pedestrian bridge can be built at a particular site, it is essential to consider

many factors, such as the need for a pedestrian bridge, the present and future traffic,stream characteristics, subsoil condition, aesthetics and cost. For the design of this

pedestrian bridge, the highest vehicles are considered so the height of 3.5m of the

pedestrian bridge has been chosen.

0.6 PROBLEM FACED

The big number of pedestrians crossing Kigali roads where zebra crossings arenot efficient enough to guarantee security of pedestrians.

The time people use waiting for priority to cross roads. The time drivers use waiting for priority to go. Tasks for pedestrians and for drivers in the roads during the crossing roads of

pedestrians.

Traffic jams in Kigali roads Inefficiency of the zebra crossing while peak period. Inattentions of pedestrians and drivers.


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Photo 5: inattention of policemen, pedestrians, and drivers

Photo 6: time west for crossing road


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0.7 TRAFFIC VOLUME STUDY

The traffic volume study was conducted with the aim of determining the number of

vehicles as well as pedestrians crossing the section of the road where the bridge is

proposed to be built, per unit time within peak traffic periods

The traffic volume counts were done manually and here below are tabulated result.

All bellow survey are counted in the period of 3 days of week mean that a number is a

mean value of 3 days of week, Monday, Wednesday, and Friday.

Table 1: traffic volume survey; Round about Kigali city, Nyarugene

Peak

period

Peak

hour

Number of

pedestrians/minute

Number of

vehicles/minute

Total number

of

pedest./hour

Total number

of vehic/hour

Morning 7h00-

8h00

59 36 3540 2160

Noon 12h30-

13h30

48 23 2880 1380

Evening 16h30-

17h30

63 42 3780 2520

MEAN TOTAL

VALUE

57 34 3400 2020


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Photo 7: Big volume of pedestrians crossing the Round about Kigali city

0.8 DATA COLLECTION FROM TRAFFIC POLICE

This is the percentage of death, injured, and accidents in the period of 2 years.

Table 2: percentage of death, injured and accident in Kigali city

Death Injured AccidentYear 2005, Jan-Dec 33,2% 66,7% 70,1%

Year 2006, Jan-Dec 27,5% 57,1% 67,1%

Source: Traffic police

Those are the accident happened in KIGALI CITY.

Year 2005: From the total number of accident which was happen in all country the

70, 1%; 33% dead; and 66, 7% injured in Kigali City only.

Year 2007: the total number of accident is 67, 1%; 27, 5% death, and 57, 1 injured.


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0.8.1 CAUSE OF ACCIDENTS INYEAR 2005-2006

Table 3: causes of accidents in Kigali city

Causes 2005 2006 %of 2006 % of 2005

Signalisation

03 08 0,23 0,065

Other 205 1373,89

4,5

High speed 573 40711,6

12,58

Inattention 2552 186452,9

56,01

State of road 43 501,42

0,94

Bad driving 871 74721,2

19,12

Alcholism 110 1243,52

2,41

Rain 11 120,34

0,24

Mecanical errors 187 1744,94

4,1

Total 4556 3523

Source: Traffic police


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0.8.2 HOUR ACCIDENT SURVEY IN YEAR 2005 AND 2006

Table 4: Daily hour accident

Hourly Year 2005 % Year 2006 %

06h00-08h00 -

08h00-09h00 230 6,5% 230 6,5%

09h00-10h00 - - 230 6,5%

10h00-11h00 - - 226 6,4%

14h00-15h00 319 7% - -

15h00-16h00 331 7,2% - -

16h00-17h00 331 7,2% - -17h00-18h00 370 8,1% 244 6,9%

18h00-19h00 338 7,4% 243 6,9%

19h00-20h00 230 6,5%

Source: National

police

As it seems from table the percentage of accident in one hour is the counted

from the total number of accident happened in one day in hourly


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CHAP I. LITERATURE REVIEW

1.1 INTRODUCTION TO SUSPENSION BRIDGES

This booklet was put together to familiarize the general reader with the terminology of

suspension bridge components and to help the designer, builder or user of a small

suspension bridge. Its use should enable him to make up preliminary calculations for

determining the cable size as well as the various quantities of material required. Then, a

comparative estimate can be made between the suspension bridge and any other type

that may also be under consideration for a particular location.

It is rather interesting to note that, in spite of the relative simplicity of design and

erection of a suspension bridge, there are a number of cases where other types have

been used, even though the suspension type might have been more economical. We

think that this is because many engineers have been of the opinion that the cable

analysis might be difficult and complicated as to its solution. However, the simple

formulae used in the catalog should dispel this thought.

True to their name, suspension bridges suspend the roadway from huge main cables,

which extend from one end of the bridge to the other. These cables rest on top of high

towers and are secured at each end by anchorages. The towers enable the main cables to

be draped over long distances.

1.2 DESCRIPTION

Suspension bridges have two basic systems-main cables supported by towers at each

end over the obstacle and a roadway suspended from the main cables. Suspender cables

support the floor beams, which support the stringers that support the roadway.

Stiffening trusses further spread the live load to the suspenders. Suspension-bridge

design requires analysis of the following items:

Load to be carried. Panel length. Floor beams and stringers.


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Stiffening trusses. Dead load. Suspenders. Main cables or suspension cables. Towers. Tower bracing and backstays. Anchorages or deadman.

Figure 1: Parts of suspended bridge

Source: hp: // www.google.com


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1.3 THEORY ON SUSPENSION BRIDGE

A suspension bridge is composed of a deck that is attached to or suspended from cables.

Just like the name states, the suspended bridge literally suspends the roadbed from huge

cables, which extend form one end of the bridge to the other. The cables are attached totwo tall towers and are secured at each end by anchorages. The tower allows the cables

to be draped over very long distances. The cable carries the weight on a suspended

bridge to the anchorages that are imbedded in solid rock or massive concrete blocks.

The cables are spread over a large area in order to evenly distribute the load inside the

anchorages to prevent the cables from breaking free.

In the suspension bridge each cable supporting a segment of the roadbed is vertically

suspended from the primary draped cable spanning between main pylon towers. The

forces from permanent and moving loads push down onto the roadbed placing it in

compression. The cables through tension then transfer the forces to the towers, which

carries the forces, through compression, directly into the earth where they are firmly

imbedded. The tension cables running between the two anchorages support the forces.

The cables stretch from the weight of the bridge and the traffic that travels from anchor

to anchor. In addition to the cables, the anchorages are also under the forces of tension.

Because they are firmly imbedded into the earth like the towers, the amount of tensionexerted on them is resisted by the counter forces of the dead load. Most suspension

bridges also have a supporting truss system underneath the bridge deck to help stiffen

the roadbed and to provide a lateral stabilization of the roadbed. This extra support

system resists wind and lateral forces and reduces the tendency of the roadbed to ripple

and sway.

Suspension bridges come in two different types of designs; the elongated "M" shape and

the "A" shaped design called a cable-stayed bridge. The two designs support the load of

the roadbed in very different ways. The differences lie in the way the cables are

connected to the towers. The cable-stayed bridge attaches all cables that support the

roadbed to the tower and they alone carry the weight of the roadbed and the traffic. The

series of cables are attached to the roadbed in two basic ways, using a running parallel


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pattern or a radial pattern. In the parallel pattern, the cables are parallel to one another

and attached at different heights along the tower. Each cable carries a segment of the

roadbed. In the radial pattern, each cable carries its section of the roadbed and they are

attached to the tower at a single point. In the cable stay bridge, all segments of the

roadbed must carry a horizontal compressive force to counter balance the equal force

from the other side.

1.4 TYPES OF SUSPENSION BRIDGES

Unstiffened bridges

Unstiffened bridges consist of floors, without stiffening trusses or girders, suspended

from cables. These bridges are suitable only where live load or wind load can never

cause serious deformation of the cable. An example of this type of bridge would be a

footbridge, where the live load is very light. Other examples are structures with a large

dead load but insignificant live load.

Stiffened bridges

Stiffened bridges have flexible cables that are stiffened by suspended girders or trusses.

These bridges minimize local changes in roadway slope due to live loads. They are

constructed by framing the floor beams of the floor system into stiffening trusses and

supporting these trusses with hangers running to the cables.

Self-anchored bridges

Self-anchored bridges are supported on vertical foundations, and no anchor cable is

required. The horizontal force on the main cable is exerted by endwise thrusts in the

stiffening girder.

Multiple-span bridges

Multiple-span bridges are a combination of two or more adjoining suspension bridges

sharing a common anchorage. The towers of these bridges are connected by a tie cable

to restrain movement of the tower tops from unbalanced live loads.


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CHAP II. MATERIALS FOR CONSTRUCTING OF THE

PROPOSED PROJECT

2.1 INTRODUCTION ON COMMONLY USED MATERIALS

Steel, Concrete, Aluminum alloy, Timber, Masonry and Fiber composite Materials fall

in three categories:

- Natural material such as stone and timber have been used for centuries asbuilding material, and their properties are well understood by craftsmen for use

in small-scale building. However, because they are natural materials, they are of

variable quality and often contain significant defects. This means that, for use in

large scale engineered structures, they need to be carefully selected andsubjected to large material safety factors to ensure safety.

- Manufactured materials such us steel and aluminum alloy are produced undercarefully controlled factory conditions, with frequent testing and monitoring

throughout the manufacturing process. This obliviously produces a more

predictable and consistent material which is reflected in lower material safety

factors being required. Concrete lies somewhere between these two being

manufactured from naturals with little intermediate processing.

- New materials such as fiber reinforced composites. They are highlymanufactured materials, but unlike steel, have not been in existence long enough

to be fully understood.

Factors affecting the selection of structural materialsThis chapter briefly describes the commonly used material. We then go on to examine

the various factors that must be considered when selecting a material for the building of

safe and durable structures. Those factors are: strength and stiffness, durability, fatigue,

brittle fracture, creep, fire resistance, weight, economics environmental factors. This is

firstly done by considering the properties of steel, which is one of the most commonly,

used materials.


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2.2 TYPES OF SUSPENSION BRIDGE CABLES

2.2.1 CABLE STRUCTURES

Cable structures can be exciting, lightweight and highly efficient. It is usual to use

cables made from a very high grade steel. This produces large concentrations of

load, and hence particular care must be taken with the design and manufacture of

end connections if catastrophic failure is to be avoided. A key feature of all design

involving cables is that they are assumed to support only tensile loads.

Figure2: 1. Galvanized Bridge Wire for Parallel Wire

Bridge Cables.

2. Galvanized Bridge Strand--consists of

several bridge wires, of various diameters

twisted together.

3. Galvanized Bridge Rope--consists of six

strands twisted around a strand core.


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2.2.2 TYPES OF WIRE CABLES

1. Parallel Wire Cables--This type of cable is made up of a large number of individual

wires which are parallel to one another. Neither the cables nor the wires are twisted in

any manner. The wire i6 shipped to the site of the bridge on reels and the individual

wires are installed or' "spun" on the bridge and later compacted together to form a round

cross section. Cables of this type are used on monumental structures, such as the Golden

Gate Bridge and the George Washington Bridge.

Figure3: Parallel Wire Cable

2. Parallel Strand Cables, Closed Construction--These consist of several

prefabricated Galvanized Bridge Strands, all laid parallel and in contact with one

another. Wood or aluminum fillers are used to bring the cable to a circular cross-

section, after which the whole cable is wrapped with wire for protection. The cable may

contain 7, 19 37, 61, 91 or 127 strands.

Figure 4: Detail of Main Cable and Cable Band The wrapping

wire is omitted at the right for clarity. Note the

closed construction and aluminum fillers.

3. Parallel Strand Cables, Open Construction--This type of cable consists of several

prefabricated Galvanized bridge Strands which are all laid parallel to one another and


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not in contact. The strands are usually arranged in the form of a rectangle and the cable

may contain 2, 4, 6, 9, 12, 16, 20, 24 or 30 strands.

4. Parallel Rope Cables, Open Construction--These are the same as Parallel Strand

Cables except that Galvanized Bridge Rope is used in place of Bridge Strand.

Figure 5: Close-up view of Main Cable, Cable Bend

and Suspender Note the open construction.

5. Single Rope or Single Strand Cables--These are used for small structures.

Figure 6: Cable with Clip Type Cable Band and

Suspender

For many years the main cables of most suspension bridges, large and small, consisted

of parallel wires installed individually at the site of the bridge. On small bridges thisproved to be an expensive procedure and consequently placed the suspension type

bridge at an economic disadvantage for the shorter span crossings.


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2.3 REINFORCED CONCRETE MATERIAL

2.3.1 GENERAL INTRODUCTION

Concrete is the most commonly used building material. It has being formed into any

desired shape most conveniently. It is an artificial stone obtained by mixing aggregates,

cement and water, and allowing the product to cure for hardening. Its essential

ingredients are cement and water, which react with each other chemically, to form

another material having useful strength. The strength of concrete depends upon the

quality of its ingredient, their relative quantity and the manner in which they are mixed,

compacted and cured. It is possible to produce concrete of different specifications for

various purposes by suitably adjusting the proposition of cement aggregate and water.

Reinforced concrete is a composite material made of concrete and steel. Plain

concrete possesses high compressive strength but little tensile strength. Reinforcing

steel possesses high compressive strength both in tension and compression. In

reinforced concrete, steel provides the strength and the concrete provides the

compressive strength. So, by combining these features and the concrete and steel, it

attains high utility and versatility.

2.3.2 CEMENT

Cement is produced burning together, in a definite proportion; a mixture of siliceous

(containing silica) argillaceous (containing alumina) and calcareous (containing lime)

materials in particular fusion, at a temperature of 1400 to 1450oC.by doing so, a

material called clinker is obtained. It is cooled and then ground to the required fineness

to get cement. Different types of cement are obtained by varying the proposition of theraw materials and also by adding small percentage of other chemicals.

Chemical composition of cement


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The main raw materials for manufacturing cement are lime, silica, alumina and iron

oxide. Depending upon the wide variety of raw materials used in the manufacture of

cement, its oxide components vary widely.

Types of cement

A wide variety of cement is available which are suitable for use under certain condition

due to its special properties. They are,

1. Ordinary Portland cement

2. Rapid hardening Portland cement

3. Extra rapid hardening cement

4. Low heat Portland cement

5. Sulphate-resisting Portland cement

6. Supersulphate cement

7. Portland blast furnace cement

8. Pozzolanic cement etc

Physical properties of cement

Following are important physical properties of cement.

1. Chemical composition loss of ignition insoluble residues lime and alumina content magnesia content and sulphur content

2. Fineness3. Formal consistency4. Setting time


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5. Soundness6. Heat of hydration and Strength of cement.

2.3.3 AGGREGATE

A mixture only of water and cement is costly and possesses low strength and shrinks

unacceptably on drying. In order to reduce the cost and modify such properties as the

strength and drying shrinkage of the hardened mass, it is usual to introduce insoluble

non-cementitious particles described as aggregates. Such aggregates usually constitute

between 50 and 80% of the volume of conventional concrete and may thus greatly

influence its properties.

Aggregates should not contain any constituent which affect the hardening of the

cement and durability of the hardened concrete adversely. It should be free from organic

matter which reduces the hydraulic activity of cement and affects its normal setting and

hardening. It should also be free from constituents whom decompose or change

significantly in volume on exposure to atmosphere or react adversely cement paste.

Physical properties of aggregates

Following are the physical properties of aggregates

1. Size of aggregates2. Shape of particles3. Surface texture4. Strength of coarse aggregates5. Specific gravity6. Bulk density7. Water absorption and surface moisture8. Bulking of sand9. Deleterious substance


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10.Soundness and Durability.

2.4 STRUCTURE OF WOOD


To utilize any structural materials to optimum effect it is necessary to understand its

composition and structures since these can have a major influence on a materials

properties. For timber this necessitates knowledge of the nature and growth patterns of

trees, since the composition and the structures of wood derive from the requirements of

the growing tree rather than the appreciation of the variations which occur between and

within species, it should then be possible to specify timber correctly for any

performance requirements.

2.4.2 CLASSIFICATION OF TREES

All commercial timber can be classified into two board groups:

Softwoods and Hardwoods When first used in the Middle Ages these terms would have

been indicate of the relative hardness, density or ease of working of the types of timber

in common use, possibly comparing native oak with imported spruce for example

(Ridout, 1992). Nowadays, however, the terms hardwood and softwood are quite

misleading: balsa is a hardwood but is softer and less dense than any soft wood, while

pitch, pine is softwood which is harder and denser than many hardwoods.

2.5 COLUMNS

2.5.1 INTRODUCTION ON COLUMNS

Columns are structural elements used primarily to support compressive loads. They are

usually square, rectangular, circular, L-shaped or octagonal in cross section.

Column subjected to pure axial load are concentrically loaded column. Such columns

rarely occur in practice. Generally they are subjected to moment along with axial load.

If the moment acts about one axis only, they are classified as uneasily eccentrically


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loaded columns. If the moments act about both axes, they are classified as biaxial

loaded columns.

2.4.2 CLASSIFICATION OF COLUMNS

Classifications of column due to its construction material are:

They are Metallic column, reinforced concrete column and brick column.

Columns are also classified as pedestal, short, and slender column depending upon its

effective length and lateral dimension. The effective length of column is the length

between the points of inflection of the column. Very short column with effective length

lesser than three times least lateral dimension are called pedestal columns. Column of

intermediate length with effective length lesser than or equal to12 times least lateral

dimension are called short columns. Columns of large length with effective length

greater than 12 times the least lateral dimension are called long or slender columns.

2.6 FOUNDATION


All structures on earth consist of superstructure and substructure. The foundation can be

defined as the substructure which interfaces the superstructure and the supporting

ground. Its purposes are to transfer all loads from the superstructure to the ground safely

and provide stable base to the superstructure. It distributes the loads over a larger area

so that pressure on the soil does not exceed its allowable capacity, the total settlement is

limited to permissible value and differential settlement is minimum possible.

These are different types of foundation for transfer of loads from superstructureto the ground. They depend primarily on the type and magnitude of the loads and the

bearing capacity of the soil. Their behavior and design are described in this chapter.


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2.6.2 FOUNDATIONS AND THE EARTH

Foundations are the structures that connect the main structure with the ground. Forces

do not end at the ends of a bridge. They do not even end at the boundaries of the

foundations. In theory, they spread throughout the earth, getting weaker as the distanceincreases, though at some point they are so weak that they cannot be detected.

Foundations must be made wide enough to reduce the stresses to values that the ground

beyond can sustain indefinitely. The size and strength of foundations will depend on the

quality of the ground. Over bridge and the famous Pisa campanile are examples where

the combination of foundations and ground were less than ideal. The foundations may

be deep underground, and in some cases under water as well, requiring the use of

pneumatic caissons with sharp cutting edges, and pressurized air keep the water out.

Eads' Mississippi Bridge and the Roeblings' Brooklyn Bridge are early examples of the

use of caissons.

If the weight of earth removed for foundations is greater than the weight of the structure

supported, the foundations on average cannot settle, because the structure is floating.

Nevertheless, a building might still tilt in these conditions, while not sinking overall.

This principle of apostasy applies approximately to huge mountain ranges, whose roots

go deep below the mean surface level of the earth. If glacier ice melts in large

quantities, the rock below will start to rise, and in fact parts of the earth's surface are

still moving slowly, and have been moving, since the end of the last ice age.

It is in dam construction that knowledge of the ground is most important, because of the

potential for great loss of life. The dam must be integrated into the rock to avoid

leakage and uplift; extensive grouting is often required. Just as important is the huge

weight of the water in the reservoir, and its effect on the rocks below and around. A

terrible catastrophe resulted when water behind the Vajont dam penetrated the ground

and enabled a large piece of a mountain slope to slide into the reservoir.

2.6.3 TYPES OF FOUNDATION

Foundations are classified as shallow and deep foundations. These are described as

follows:


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1. Shallow foundationit has a smaller depth limited to the width of footing. It spreads

The load from superstructure on a larger area of the soil so that stress intensity is

reduced to a value which can be carried safely by soil they are classified as isolated

and combined footing.

2.Deep foundation when the top layer of soil is too weak to support the structure on a

Shallow foundation, the depth of foundation is increased till more suitable soil is

found to support the structure. Such a foundation is termed as deep foundation

because of its large depth. Different types of deep foundation are pile foundation and

well foundation

2.7 BEARING CAPACITY OF SOIL

Bearing capacity of soil is the maximum intensity of load or pressure developed under

the foundation without causing failure of soil and damaging settlement of superstructure

supported on foundation. Therefore allowable bearing capacity is evaluated with an

adequate factor of safety against ultimate bearing capacity of soil and adequate margin

against excessive settlement. The ultimate capacity of soil corresponds to load beyond

which settlement increases rapidly.

Soil pressure at footing bases

Actual soil pressure at the base of the infinitely stiff footing resting on ideal cohesion

less and cohesive subsoil under a concentric load generally footings are not infinitely

stiff and very few soils exhibit such behavior.

2.8 LOADING

Analysis of begins with the evaluation of the structures own weight and the loads to be

supported, such loads are variable both in magnitude and some in position. In general,

there are two types of loads which are dead and imposed loads.

Another type of load frequently encountered in building is wind load which is the

impact of the local wind on the structure. The wind speed is converted to force and the


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effect on the structure is analyzed. This is common with tall structures such as tall

buildings and bridges. Wind loads can also be combined with both dead and imposed

loads.

2.8.1 DEAD LOADS

The dead loads are the weight of the structure its self, and the structural element such

as ceiling, I beam, floor board, cladding, cables and permanent partitions, where panels

and other equipments are permanently located they can be assumed as dead loads.

2.8.2 IMPOSED LOADS

These are loads to be carried by the structures and because of their nature are more

different to be determined precisely. For many of them, it is only possible to make

conservative estimates based on standard codes of practice or past experience.

e.g.: imposed load for bridges: pedestrians, panels, vehicles, etc.

For houses: its occupants, furniture, and presence of wind

2.8.3 DESIGN STRESS

This study is mostly concerned with two materials namely concrete and reinforcements.

The steel used is round bars of high yield steel or high tensile bars. Concrete

characteristics strength fck = 30KN/mm3. This value of fck is also minimum cube

strength at 28 days. All Characteristics strength are given in DIN codes and British

Standards; for mild steel rand bars, fyk=250N/mm2 while for high yield steel,

fyk=420N/mm2.


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CHAP III METHODOLOGY

These data collection methods have been used to collect needed data:

Observation:This method has been used to enable traffic study and collect some preliminary data at

the selected site which would help in making conception, analysis as well as design of

an economic flyover suspended pedestrian bridge and Providing detailed plans and

drawings of final structure.

Literature Survey :Internets and books have been used in order to get secondary data need for designing

and getting the required calculations and formulas.


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CHAP IV DESIGN OF FLYOVER SUSPENDED PEDESTRIAN

BRDGE


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4.1 DESIGN INFORMATION

Properties of various materials to be used in design

Concrete strength at 28 days 25 kN /m3 and fck, cyl=20 N/mm2,fck, cube= 30N/mm

Timber 8 6 kN/m3 Steel rolled or cast 74 kN/m3

Unit weight of various sheet materials

Timber boards 0.15 kN/m2 Steel sheeting 0.15 kN/m2 Live load 5 kN/m2 Stair live 5 kN/m2 Imposed load 3 kN/m2 Allowable compression stress of column 210 kN/mm2 Allowable stress for cables 240 N/mm2 allowable shear stress for I beam 210 N/mm2 The assumed soil bearing capacity in Nyarugenge is 200 kN/m2 = 0.02

kN/cm2.

4.2 DESIGN THEORY

The cable has a uniform weight and may also be subjected to a uniformly distributed

load. The tension is assumed to be sufficiently great to that the sag f is not large. Since

the curve is reasonably flat, the weight of the cable may be replaced, with the practical

error by a uniform loading w, then

- y = wc2/8TSince the curve is flat, the true length of cable is

- L =c+Where from the following formulas:

- = 8y2/3c


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Figure 7: bridge span, UDL and flesh

Where, l is the true length of the cable- y is deflection- w is load (kN/m)- C is span- T is tension force- is elongation

In order to find the maximum force in cable that is better to have the horizontal

component and vertical component.

Horizontal component

RCH

= wL/8y and the vertical component

RCV = wL/2

Cable will exert the maximum stress. The maximum stress is obtained by the force per

unit area which is equal to the allowable stress. The max force

F max= {(wL/2)2+ (wL

2/8y)}

1/ 2

And we know that the maximum stress = Max force/Area

Or, Area = max force/max stress

Where area A is the cross section of one suspended cable

A = D2/4

D is diameter of cable

= 3.14


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4.3 DESIGN OF MAIN CABLE DIAMETER

Surface area of the moving space area 1.5m of width and lengthlof 15.2m

Design parameters

Floor surface area = 1.5*15.2= 21,28m2

Deflection y=1.4m

Number of main cable = 2 cables

Working cable stress = 240 N/mm2

Live load = 5 kN/ m2

Timber boards = 0.15 kN/m2

Imposed load = 3 kN/m2

Design load

Dead load = ((live load + timber board)*l)

Where l is the of opposite distance of center to center of the span l = 1.4 /2 = 0.7 m

Cis the span

Dead load = ((5 + 0.15)*0.75) = 3.862 kN/m

Balustrade =1.0 kN/m

Imposed load = 3 kN*0.7 = 2.1 kN/m

Total load = 3.862+1.0 = 4.862 kN/m

Then design load = (4.862*1.4) + (2.1*1.6) = 10.17 kN/m

W= 10.17 kN/m per cable span

Figure 8.1: load diagram


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Design of main cable diameter

Reaction of horizontal componentRCH=wC2/8f

RCH = 10.17*15.22/8*1.4 = 209.726 kN

Reaction of vertical componentRCV = wL/2

RCV= 10.17*15.2/2 = 77.292 kN

Thus the maximum force = (RCV2+RCH

2)

1/2

Fmax = (209.7262+77.292

2)

1/2= 223.515 kN

Area = max force/max stress

A = 223.515*103/240 = 931.31 mm

2

Then the diameter of main cable is equal to (931.31*4/3.14)1/2

= 34.44 mm

Take the cable diameter of 3.5 cm for each main cable.

Figure 8.2: result of diagram cable


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4.4 DESIGN OF TRUE LENGTH OF MAIN CABLES

Calculation of true length

- y = wL2/8TSince the curve is flat, the true length of cable is

- l = L+Where from the following formulas

- = 8y2/3LWhere, lthe true length of the cable- y is deflection- W is load ( kN/m)- L is span- elongation- l is true length

Then, = 8*1.42/3*15.2 = 0.344 m

Thusl=15.2 + 0.344 = 15.544 m

The true length lof cable between the towers is 15.544m


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4.5 DESIGN OF TRANSVERSAL AND LONGITUDINAL BEAMS

4.5.1 DESIGN OF TRANSVERSAL

Beam B1Beam support to carry lateral load which are resisted by bending and shear. However,

deflections and local stresses are also important. Beam may be cantilever, simply

supported, fixed ended or continuous. In this work we are going to use simply supported

beam and is uniformly distributed load.

Figure 9: transversal beam

Design loadLive load = 5 kN/m

2

Timber structure = 0.15 kN/m2


Dead load: 5+0.15 = 5.15 kN/m2

Then, total load is 5.15*0.77 = 3.965 kN/m

Where 0.77m is equal to the half of lateral distance of walkway

Imposed load = 3 kN/m2*0.77 = 2.31 kN/m

Design load = (3.965*1.4) + (2.31*1.6) = 9.247 kN/m

Max moment = wL2/8

Deflection = 5wL3/384EI

w: is the design load

L: is the considered length


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I: is the moment of inertia and

E: is the elasticity modulus

Evaluation of beam reaction, shear force and bending moment

Two end ReactionRA andRB = wL/2

= 9.247*1.7/2 = 7.86 kN

The resulting diagrams are shown in figure below. Beam B1 is standard case i.e. a

simply supported beam with uniformly distributed load.

M max = wL2/8

=9.247*1.72/8 = 3.34 kNm

Figure 10: load, shear, momentdiagram

Let use a typical yield stress of yis 210 N/mm2(St 25) DIN 18800 German standard

From equation required S = M max/y

= 3.34*106/210*10

3= 15.905 cm

3

Where S is plastic modulus

UDL, Reaction and moment diagram for beam B1

Use I 80 DIN 1025which have cross section area of 7.57 cm2

Average shear stress = 7.86*103/7.57*10

2= 10.515 N/mm

2< 139N/mm

2


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Beam B2Design of beam in 1,4m of transversal distance from the towers

Load on the Uniformly Distributed Load on beam

5.15*0.89 = 4.584 kN/m

Where 0.885m is equal to the half of perpendicular distance of the span and 1.7m is the

length taken in design.


Design load = (4.584*1.4) + (2.655*1.6) = 10.07 kN


= 10.07*1.7/2 = 9.086 kN

The resulting diagrams are shown in figure 10. Beam B1 is standard case i.e. a simply

supported beam with uniformly distributed load.

M max = WL2/8

= 10.07*1.72/8 = 3.64 kN m


= 3.64*106/210*10

3 = 17.333 cm

3 Try I 80 DIN 1025

4.5.2 DESIGN LONGITUDINAL BEAMS

Beam B3 of 1.4 m lengthDesign load

Design of beam of 1,4m of longitudinal distance from the towers


Live load = 5 kN/m2

Timber structure = 0.15 kN/m2


Dead load: 5+0.15 = 5.15 kN/m2


Where 0.75m is equal to the half of lateral distance of walkway


Design load = (3.8625*1.4) + (2.25*1.6) = 9.007 kN/m



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= 9.007*0.894/2 = 4.026 kN



M max = wL2/8

=9.007*1.42/8 = 2.207 kNm

Figure 11: load, shear, moment diagram


= 2.207*106/210*10

3= 10.509 cm

3

Try I 80 DIN 1025 having area of 7.57 cm2

Beam B3Design of beam of 0.77m length of longitudinal distance in 2.94m from the towers


5.15*0.75 = 3.8625 kN/m

Where 0.885m is equal to the half of perpendicular distance of the span and 1.7m is the

length taken in design.


Design load = (3.8625 *1.4) + (2.25*1.6) = 9.007 kN


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= 9.007*0.77/2 = 3.467 kN

The resulting diagrams are shown in figure 11. Beam B3 is standard case i.e. a simply

supported beam with uniformly distributed load.

M max = wL2/8

= 9.007*0.772/8 = 0.667 kN m


= 0.667*106/210*10

3= 3.176 cm

3


4.6 DESIGN OF SUSPENDERS CABLE DIAMETER

Design reaction in the suspenders is equal to the reaction in the beam floor

Reaction or tension R = 10.22 kN

Area = tension/max stress

A = 10.22*103/240

A = 45.583 mm2

Then, cable diameter D = (45.583*4/3.14)1/2

= 7.62 mm = 0.762 cm

Take the cable diameter of 0.8cm for each suspender

Figure 12: suspender cable diameter


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4.7 DESIGN OF TOWERS

Determination of the dimension of suitable standard universal columns

Load in one tower is 77.292 kN

Design load for 1 column 77.292 kN

Length of the columns 6 m = 6000 mm

The estimated Compressive strength at the member is 210 N/mm2

Appropriate area = design load/estimated stress and the

Actual stress = design load /actual area

Figure 13: load column

Design of one tower

Approximate area = 77.292*103/210*10

2= 3.68 cm

2

Checking of Deflection:

Shear force = 5wL3/384EI

Allowable shear force =L/325

Actual shear force = 6000/325 = 18.46mm

I = 384*52.9*18.46*102/ (5*77.292*6

3) = 449.33 cm

4

Use I 140 DIN 1025


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Figure 14: column and beam dimension

4.8 DESIGN OF FOUNDATION

Data

Load w = 77.292 kN

Concrete class c20/25gives:

Use Soil bearing pressure of soil= 0.02 kN/cm2

Compression resistance of concrete fck,cyl= 20 N/mm2, fck, cube= 25N/mm

2

Tension resistance of concrete fcy= 460 kN/cm2

Calculation of DimensionRequired area of foundationA = w/soil

A = 77.292/0.02 = 3864.6 cm2

Use square foundation, width of pad bf = (3864.6)1/2

=62.166 cm

Take width bf of 63 cm.

Depth of pad is equal to B*1/6

D = 63/6 = 10.5 cm

The depth of 10.5 is very small, so we can take D = 20 cm

Use a foundation of B = 63 cm square and 20 cm deep

Figure 15: foundation


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ReinforcementFor concrete cover of 5 cm and assuming 1.0cm diameter bars, the effective depth d of

the top layer of reinforcement is:

d1= 10.5-5-1.0-0.5 = 4

d2= 20-5-1.0-0.5 = 13.5 cm

As = M max/0.9* d1*Rs

Ground pressure, q = w/B2= 77.292/632= 0.01947 kN/cm2 = 194.7 kN/m2

And maximum moment = p*lc*bf* (lc/2)

0.02*24*63*24/2 = 362.88 kNcm

As = 362.88*103/0.9*40*37.5 = 268.8 mm

2

Cross sectional area of one bars = 102*3.14/4 = 78.5

Number of bars = 268.8*4/78.5= 3.424 bars

Take 4 bars


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Figure 16: Reinforcement in foundation

Shear

Shear across the pad:

Actual Shear force 0.54*d2*bf*RbtActual shear force = q*bf* (lc- d2)

= 0.02*63* (24-13.5) = 13.23 kN

Actual Shear force 0.54*0.09*13.5*63

13.23 < 41.33

Proposed dimensions and reinforcement are satisfactory.

Figure 17: distribution of bars

4.9 DESIGN OF COLUMN BASE

The column is axially loaded slab base; the column has 152*152*37 Kg which carries a

total load of 77.292 adopting a square slab.

The concrete strength is 30kN/mm2.


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Design load = 77.292kN

Area = 77.292*103/0.4*30

= 5520.857 mm2

Make the base of 600mm square.

Pressure P = 77.292*103/600

2

P = 0.215 N/ mm2

The arrangement of the column on the base plate is shown in figure below. From this

Project base a =224 for all side

Figure 18: base column

Assume the thickness of plate is less 40mm. design strength = 265N/mm2(Table 6)

The thickness of the base plate is given by:

t = ((2.5*0215)/265*(2242-0.3*224

2))

Thickness t = 8.38 mm

Design of thickness of welding

Thickness of weld = 0.7* leg length

Let assume the leg length = 1 cm

Then, t = 1*0.7 = 0.7 cm


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4.10 DESIGN OF STAIRS LONGITIDUNALY BEAMS

Data

Rise = 300 cm

Going = 300 cm

Waist = 250 cm

Number of rise 12 risesSpan = 460 cm

Loading

Live load = 5 kN/m2

Timber structure load = 0.15 kN/m2


Dead load: 5+0.15 = 5.15 kN/m2


Where 0.70m is equal to the half of lateral distance of walkway of stairs


Design load = (3.605*1.4) + (2.1*1.6) = 7.14 kN/m


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Figure 11: load, shear and moment diagram

Calculation of negative moment

Formulas used

w = 7.14 kN/m

MB * lAB + 2MB (lAB+ lBC ) + MC * lBC= -wlAB3/4-wlBC

3/4

MB*lBC+2 MC (lBC-0)+0 =-wlBC3/4

2MB*5.475+ MC*2.58 = -7.14*(2.8953/3)-7.14*(2.58

3/4)

2.58 MB+ 2 MC*2.58 = -7.14*2.583/4

10.95 MB+2.58 MC= -73.96 (*-2)

2.58 MB+5.16 MC= -30.65 (*1)

21.9 MB+5.16 MC= 147.92

2.58 MB+5.16 MC= -30.65

-19.32 MB= 117.27

MB = - 6.069 kNm


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MC = -2.91 kNm

Calculation Positive moment

Mx= Mo + Mn-1+ (Mn-Mn-1)/ln

Mo= 7.14*2.8952/8 = 7.48 kNm

MAB= 7.48+ (6.09*1.45/2.895) = 4.44 kNm

Moo = 7.14*2.582/8 = 5.94 kNm

MBC= 5.94-6.09 + ((-2.9+6.07)/2) = 1.43 kNm

Then, to find out the dimension of beam we use the maximum moment

Thus, M Max is Mo= 7.48 kNm

Plastic modulus,

S = M max/y

= 7.48*106/210*103= 35.619 cm3

Take I 140 DIN 1025 for each beam of beam

4.11 DESIGN OF LATERAL BEAMS OF STAIRS

Design load = 7.14 kN



= 7.14*1.4/2 = 4.998 kN



M max = wL2/8

=7.14*1.42/8 = 1.75 kNm

Figure 11: load, shear, moment diagram


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= 1.75*106/210

3= 8.33 cm

3


4.12 DESIGN OF SUPPORT COLUMN OF STAIRS

Determination of the dimension of suitable standard universal columns

Load in one column is =7.747 kN/m *

Length of the columns 3.3 m = 3300 mm

The estimated Compressive strength at the member is 100 N/mm2

Appropriate area = design load/estimated stress and the

Actual stress = design load /actual area

Figure 20: stair column


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Design of column

Reaction at the support = wl2/2

= 7.717*1.4/2 = 5.43 kN

Approximate area = 5.43*103/210*10

2= 0.26 cm

2

Checking of Deflection:Shear force = 5wL3/384EI

Allowable shear force =L/325

Actual shear force = 3300/325 = 10.15mm

I = 384*52.9*10.15/ (5*5.43*100*3.33) = 21,132 cm

4

Use IPE 120

4.13 DESIGN OF FOUNDATION FOR COLUMNS OF STAIRS

Design data

Load w = 5.43 kN

Concrete class c20/25gives:

Use Soil bearing pressure of soil= 0.02 kN/cm2


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Compression resistance of concrete fck,cyl= 20 N/mm2, fck, cube= 25N/mm

2

Tension resistance of concrete fcy= 460 kN/cm2

Required area of foundationA = w/soilA = 5.43/0.02 = 271.5 cm

2

Use square foundation, width of pad bf = (271.1)1/2

=14.53 cm

Take width bf of 20cm.

Depth of pad is equal to B*1/6

D = 20/6 = 3.3 cm

The depth of 3.3 is very small, so we can take D = 20 cm

Use a foundation of B = 20 cm square and 20 cm deep for each foundation of

tower.

4.14 DESIGN OF ANCHORAGE BLOCKS

Figure 21: anchor and fixation of cable

Source: hp: // www.google.com/design of suspended brigdes/anchorageA2

Weight of one anchor block:

WA= Tension in cable*cosine between cable and earth surface

And Weight*DW> Tension *DT

DW: horizontal distance

DT:vertical inclined distance


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Let assume DW = 1 m

Max force or Tension in cable = 223.515 kN

Angle = 590

Then, WA = 223.515*cosine 590= 115.18 kN

Thus, the weight 115.18 kN

Weight*DW > Tension *DT

115.18*1 > 223.515* DT

DT = 1.94 m

Use the anchor of vertical inclined distance of 1.94m and horizontal distance of 1.0m

The volume of anchor =115.18/25 = 4.6 m3

Surface area of bloc = 4.6/1.94sin600= 2.738 m2

Where 1.94sin600is the true height

Take a square base surface = (2.737)1/2= 1.65 m

H = 1.68m, B = 1.65m, L =1.65, DT= 1.94m and DW= 1m

4.15 DESIGN CONNECTIONS WITH BOLTS

For ordinary bolt of grade 4.6 the value of shear stress given in table 30 of bs 5950: Part I: 2000

as 160N/mm2

For bolts the gross diameter is, of course, equal to the nominal diameter. Therefore the safe load

in single shear, or single shear value (ssv)

Shear stress = w/area of 1 bolt, i.e. 160 = w/ area of 1 bolt

Where area of 1 bolt = 3.14*d2/4

Data, for beams, maximum load = 7.48 kN

Shear force = 160 N/mm2

Then A = (7.48*103/160)1/2= 46.75mm2

Diameter D = 7.717mm

Use D = 8mm for each bolt.

For column, maximum load is 77.292 kN

Shear force = 160 N/mm2

Then A = (77.292*103/160) = 483 mm2

Because we have 4 bolts in the base of column

One bolt has diameter D =12.4 mm

Use D = 13 mm for each bolt


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REFERENCES

BOOKS USED:

1. Foundation design and construction, M. J Tomlinson, sixth Edition, 1995,Addison Wesley Longman

2. Steel work design guide to BS 9550: Part I: 1990, volume I, section propertiesand member, capacitors, fifth Edition, 1997, the Steel Construction Institute

3. Structure steel work, design to limit state ,second edition4. Understanding structures analysis, material, design, second Edition, (1998),

DEREK SEWARD (1998)

INTERNETS:

(http://www.google.com/analysis of suspension bridges) (May 2007)

(http://www.google.com/unstiffened bridges) (May 2007)

(http://www.google.com/Multiple-span bridges) (August 2007)

(http://www.google.com/suspension bridges) (August 2007)

(http://www.google.com/design of suspended brigdes/anchorageA2) (August 2007)


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APPENDICES

m 2008 Ceet 01 Ryoba Vuzimpundu Eugene Gs20031702

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