STRUCTURAL DESfG OF A REINrORCED CO CRETE

FLOATI G PONTOON WITH A AC 'E WALKWAY

T A.J~ CHAN BOON

Universiti Malaysia Sarawak

TA 2002

439

Tl61

2002

P.KHIDMAT MAKlUMAT AKADEMIK

UN1MAS

111111111111111 II1I 1111111111 0000107255

Universiti Malaysia Sarawak KOla Sant8J'ahan

BOItANG PENYERAHAN TE5IS

JuduJ: Structural Design of a Reinforced Concrete Floating Pontoon wiill an Access Walkway

SESI PE GAJ1AN: J999 - 2002

Saya TAN CHAN BOON

(HURUF BESAR)

mcngaku membenorilan t

APPROVAL SHEET

This project report attached here to, entitled "Structural Design of a

Reinforced Concrete Floating Pontoon with an Access Walkway" prepared and

submItted by Tan Chan Boon in partial fulfilment of the requlremenls for the

Degree of Bachelor of Engineering (Civil) is hereby read and approved by:

Date:_g_ ~__2-__°I-/_~-J/?

STRUCTURAL DESIGN OF A REINFORCED CONCRETE FLOATING

PONTOON WITH AN ACCESS WALKWAY

TAN CHAN BOON

This report is submitted in partial fulfilment of the requirement for the

Dachelor Degree in Civil Engineering (Hons.)

from the

Faculty of EnglDeering

University of Malaysia Sarawak

March 2002

ACKNOWLEDGEMENTS

My sincere thanks to my supervisors, Mr. Anthony Law Ngo King. the

Managing Director of Jurutera Jasa (Sarawak) Sdn Bhd and Dr. Ng Chee Khoon

for thelI unwavering support and guidance received throughout the period of

thla project.

I alBo would Wee to express my sincere apprecultlon to StructuraL

Engineer of Jurutera Jasa (sARAWAK) SON BHD. Mr. Voon for his aaeiJltance

in completlng various taake.

I also wouLd like to express my sincere apprecialion to all the l!ection

leaders and engineers, and draughtepersons in JURUTERA JASA (SARAWAK)

SON BHD for their assistance in completing various task .

1n addition, I would like to thank Miss Norazzlina for her help regardmg

the usage of Staad III program and allowing me to borrow Staad III dongle.

Finally my appreciation goes to my family and friends for thelI love and

support.

ABSTRACT

The project presented herein is the structural design of a reinforced concrete

floating pontoon with an acce88 wall-way. For the analysis and design purposes, two

8tructuralsoitwares were adopted, which are Staad ill and MicroFeap II.

This project is mainly concerned with the detail design of the reinforced

floating pontoon, truss analysis and timber decking for walkway. The British Code

of practices as 8UO, BS 5950 and BS 5268 are used respectively in this project.

The mooring and anchoring system is nol included in tllia project. Energy

absorption, for e~lImple, using rubber fenders or timber is also not included.

Output resulta generated by the software will be analysed and followed by

the structural elements design state. Eventually, detail drawings are produced to

illu8trate how structure is to be constructed on site.

This thesis is concludod in improving the reinforced concrete floating

pontoon wltb conclusion and some recommendations on the project are stated too.

II

ABSTRAK

Projek tabun akbir ini meranglrumi rekabentuk struktur bagt. kOnkriL

pontun dan pelalu jalan kaki. Perisian struktur yang digunakan dalam

rekabentuk adalah Staad mdan MircoFeap U.

Tumpuan utama diberi kepada merekabentuk struktur bagi konkrit

pontun, kelruda dan kayu dek aahajaPiawaian kode yang digunakan adalah BS

8110, BS 5950 dan BS 5268 dalam projek ini.

Sistem tambatan dan penyerapan tennga oleh penangkia pukulan bdak

termll8uk dalam perbincangan projek ini.

Keputusan keluaran daripada perisian sturktur akan dikaji dan diikuti

dengan peringkat merekabentuk struktur binaan. Selepas itu luman struktur

akan dibll8ilkan untuk memberi gambaran mengenai struktur hinaan sebenar di

tapak binaan. Cadangan untuk kerja-kerja memperbaiki turut diberi.

ill

LIST OF CONTENTS

ACKNOWLEDGEMENT i

• ABS'l'RACT 11

ABSTRAK Lii

L1ST OF SYMBOLS VIii

LIST OF CONTENTS IV

LIST OF FIGURES xv

UST OF TABLES XVI

CHAPTER 1 I NTRODU{,'TIO

1.1 [ntroduction 1

1. 2 Project, Objectives 2

l.3 Thesis Overview 2

CHAPTER 2 LITERATURE REVIEW

2.1 General 4

2.2 History of floatlllg pontooo 5

IV

CHAPTER 3 CASE STUDY AND METHODOLOGY

3. l

4.1.1 Assumptions mad~ 33

4.1.2 Freeboard of the floating pontoon 37

U .3 Input Procedure for Staad III 38

4.1.4 Result.s (extracted from Appendix AI) 43

4.1.5 Summary of member end forces from St.aad ill analysIS 44

4.1.6 Manual calculation 46

REFERENCES 77

APPENDIX A STAAD III INPUT AND OUTPUT DATA FOR 78

REINFORCED CONCRETE FLOATING PONTOON

APPENDIXBl STAAD III INPUT AND OUTPUT DATA FOR tOO

WALKWAY DESIGN - CONDITION I

APPENDIXB2 STAAD III INPUT AND OUTPUT DATA FOR 112

WALKWAY DESIGN - CONDITION II

APPENDIXC T ABl.E PROPERT! ES OF TIlE STEEL SECTION 124

APPENDIXD U-FRAME ANALYSIS USING MICROFEAP II : 127

INPUT AND OUTPUT DATA

VII

SYMBOLS

For the purpose of this Chapter, the following symbols have been used. ThesIl have

largely been taken from BS 8110. Note that in one or two caaes the same symbol is

differently define

yr

K

M

SHEAR

8,

v

v

v,

Characteristic imposed load

Cbaracwristic wind load

Charac(.(mahc atrength

Characteristic compressive cube strength of concrete

CharacterlBtic tensile strength of reinforcement

Partial Raf!'ty factor for load

Partlru safety factor for materialatrength

Coefficient given by MJ£.ubd'

Design ultimate moment

Design ultimat.e moment of reSlBtance

Area of tension reinforcement

Characteristic R!rength of linkll

Spacing of li.nks along the member

Design shear force due to ultimate loads

Design shear stress

Design concrete shear atre8S

1'otlll cr088"sectional area of shear reinforcement

LX

For IbJB purp06e6 of tbJB 6ection, the following 6ymbols bave been used. These have

largely been taken from BS 5268.

GEOMETRr

h

h

A

I

Z

Bending

L

M

MR

Deflection

&

m

AL /{OPER1'IES

Breadth of beam

Depth of beam

Total cr08s-sectional Rrea

Radius of gyration

Second moment of area

Sect ion modulus

Effecttve Apan

Design moment

Moment of resis tance

Applied bending stress paraU€1\ to grain

Grade bending stress parallel to grain

Permissible bencling stress parallel to grain

1'olal denection

Bending deflection

Shenr deflection

Permisailile deflection

"

E

Em..n

G

Shear

F,

t .

t.

t....

bearing

F

Ib

Compression

L

A.

N

Ot: fldm ,j r

Modulus of ela ticity

Mean modulus of elasticity

Shear modulus

Design sheaT force

Applied shear 8t ress parallel to gr8.Ul

Grade shear stress pa.rallel to grAin

Permiaaihle shear stress parallel w grain

Bearing force

Length of hearing

Applied compression stress perpendicular to gr8.Ul

Grade compression stress perpAndicuIar to grain

Permissible bending stress perpendicular to grain

Effective length of a coIllInn

Slcnderncsa ratio

Axial load

Apphed compression stress parallel to grain

Grade compression BITeRS parallel 1.0 grain

Perrrusswie compreSSiOn stress parallel to grain

Xl

aen Uiled Tht'Re have

largely been taken from BS 5950

GEOMETRIC PROPERTIES

A Area of section

A. Gross sectional area ofsteel section

R Breadth of section

B Outstand of nange

D Depth of section

o Depth of web

1" I, Second moment of area about tbe major and minor RXt'1l

L Length of spa"

r., r Radius of gyration of a member abut its major and minor axes

S" ~ PlastiC modulus about the major Bnd rumor axes

l' Thickness of flange

l' Thickness of web

U Buckling parameter of the aechon

x Torsional mdex of sectlOn

7-4) Z). Elastic modulus about major and minor axes

Bending

X1l

A, Shear area

E Modulus of elasticity

F, Tensile force

F. Shear force

L Actual length

Lt; Effective length

Mmfl • Maximum moment

M., Moment capacity

Mt. Buckling resistance moment

P. Shear capacity of a section

pc (',ilmpreasive strength of the ateel

p. Bending strength oftha steel

p, Design strength of steel

& COll8tant=(2751p,)·t,

/,. Slenderness ra tio

0 deflection

COMPRESSION

1\0 Grosa sectional area of steel section

L Actual length

Lt: Effective length

Mt. Buckling resistance moment

CONNECTIONS

xili

T Thickness of ply

E End distance

F. applied shear force

F, Applied tension force

f, SheIlI' stress

Pol, Bearing CIIpacity of a holt

p". Bearing CIIpacity of parte connected by ordinary bolts

p. Shear CIIpacity of 0 holt

pbb Bearing strength of a holt

Pbtr Bearing strength of porta con~ected by friction grip fasteners

pt.o Bearing strength of parte connected by ordinary holtl!

p. Shear strength of 8 holt

Pt Tension strength of a bolt

p_ Design strength of 8 fillet weld

S Leg length of 8 fillet weld

xiv

LIST OF FIGURES

Fig. 3.1 Side Elevation showing poesibie poaition of floating pontoon 10

section; (d) L-section

Iaatie support 8tiffn088

frames

Fig. 3.2 Beam sectiOIl8: (a) Singly reinforced; (b) doubly reinfon:ed;(c) T- 18

Fig. 3.3 Common types of trusses 23

Fig. 3.4 SloeeI truss wa Ikway pIan for the project 24

Fig. 3.5 Buckling of main beams of half-through girder 25

Fig.3.6 U-frame restraint aclion.(a) Components ofU-Frame, (b) U-Frame 26

Fig. 3.7 Buckling made for half-through construction with flexible and 26

Fig. 4.1 Geometry modelling of floating pontoon USl.Dg Staad In program 34

Fig. 4.2 Top key plan of floating pontoon 35

Fig_ 4.3 Bottom key plan of floating pontoon 36

Fig. 4.4 Pontoon overall Iayout, elevation and detaila 71

Fig. 4.5 Pontoon key plan, beam and slab details 72

Fig. 4.6 Pontoon walkway plan and sectional details 73

xv

IJS'I' OF TABLES

Table 3.1 TIde levels

• I

9

T Thickness of ply

E End distance

Fe applied shear force

F, Applied tension force

(, Shear stress

Pbl> Bearmg capacity of a bolt

Pb. Bearing capacity of parts connected by ordinary bolts

P. Sbear capacity of a bolt

Phb Bearing strength of a bolt

Pb. Bearing strength of parts connected by fnction grip fasteners

ph. Bearing strength of parts connected by ordinary bolts

p; Shear strength of 8 bolt

p, Tension Atrength of 0 bolt

p_ Design strength of II fillet weld

S Leg length of a fillet weld

xiv

CllAP'rER 1

INTRODUCTION

1.1 General

FJoatmg pontoon L8 a broad, flat'bottomed floating structure generally

rectangular in shape, used for many purposes in a port, as a ferry landmg place,

a pIer head, or alongside a vessel to assist in loading or discharging.

Historically floating pont.oona are used chiefly to support a bridge, to

raise a sunken shIp, or to float a hydroplane or a floating dock. Pontoons have

been built f wood. of hades stretched over wicker frames, of copper or tIn sheet

metslsheathed over wooden frames. of aluminum. of concrete and of steel.

Pontoons for raising sunken ships are watertight cylinders that are filled

with water, sunk, and fastened to the submerged ship; when emptied by

compressed air. they float the ship to the surface. A pontoon lifeboat conaists of a

raft. supported by watertight cyhnders.

The modem permanent pontoon is composed of many compartments, so that if a

leak occurs in one compartment, the pontoon will not SInk. Permanent pontoons

are fastened together and several anchors are dropped from each. However in

1

I • ' r

"

this project, the pontoon unit is small Therefore no compartmentation is

mtroduced. The partition wall makes the reinforced concrete box unit too heavY.

1.2 Project Objectives

The main objective of this project is to perform a structural design of II

reinforced ncrete floating pontoon with an access walkway based on BS 8110:

Part 1 (1985), BS 5950 (990). BS 5268 (1996) and BS EN 388 (1995).

In designing the reinforced concrete floating pontoon, computE'r analysis

and manual calculation are used. For steel truss and cross members design,

computer software is used. Timber decking design ill based on manual

calculation according to BS 5268 (1996).

Detail structural drawmgs are also included to illustrate how the

structure is constructed on the site.

1.3 Thesis Overview

This thesis describes the project of structural design of a reinforced

concrete floating pontoon with an access walkway. Following the introduction,

the next chapter gives an overview of the floating pontoon lllcluding a brief

history and background of floating pontoons.

2

; .

The description about the case study and methodology are in Chapter 3 of

this report where it focuses on the specification and the procedures involved in

designing the reinforced concrete floatmg pontoon, timber declung and aocess

walkway design. Chapter 4 is concerned with the detailed design and calculation

of reinforced concrete floating pontoon with an access walkway. Chapter 4 alae

included the detailed structural drawings for reinforced concrete floating

pontoon and aocess walkway. The thesis is concluded in Chapter 5.

3