Suspended Bridge

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STRUCTURAL CALCULATION

SUSPENDED BRIDGE


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PEDESTRIAN SUSPENDED BRIDGE


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TABLE OF CONTENTS

1.1 INTRODUCTION 2

1.2 ARCHITECTURAL INPUTS 2

1.3 LOAD ANALYSIS 4

1.3.1 CONSTANT LOAD 4

1.3.2 LIVE LOAD 4

1.3.3 ACCIDENTAL LOAD 4

1.3.4 WIND LOAD 4

1.3.5 LOAD COMBINATIONS 4

1.4 STRUCTURAL DESIGN 5

1.4.1 SUSPENDERS 5

1.4.2 HANDRAIL 6

1.4.3 MAIN CABLES 7

1.4.4 DECKING 11

1.4.5 CROSS BEAMS 13

2. CONNECTIONS 14

2.1 TOP SUSPENSION ROPE CONCRETE COLUMN 14

2.2 HANDRAIL CONCRETE COLUMN 15

2 3 BOTTOM SUSPENSION ROPE CONCRETE COLUMN 16


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Pedestrian Suspension Bridge1.1 INTRODUCTIONThe span for pedestrian suspended cable bridge is 20,7m divided in 10 parts. Bridge walkable width is80 cm. Referenced floor level is 140.70 but in middle of span level of horizontal suspension cable is

0.5m lower. Top suspension cables are attached to concrete columns 900x20cm on elevation 143.30mnm.

1.2 ARCHITECTURAL INPUTS


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Pedestrian Suspension Bridge


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Pedestrian Suspension Bridge1.3 LOAD ANALYSIS1.3.1 CONSTANT LOAD

Assumptions/Conversions Loading

SuspendersGERRO16-B (or equivalent)

SL1 2,5m 4 pcs

SL2 1,8m 4 pcs

SL3 1,5m 4 pcs

SL4 1,2m 4 pcs

SL5 1,1m 2 pcs

Weight: insignificant

Cross beams PFCH 100x50x10mm, L= 1000mm

(11 pcs)

Weight: 0,102 KN/m

Weight: 1.122 kN

Decking

4 cm x 75 cm x 210 cm,

V1 = 0.063 m (10pcs), V10=0,63m3

Decking area: 15,52 m2

Timber, assume 9,5 KN/ m

15.52m2

0,38 5,89KN

Total: 5,89KN

Cables12 mm 7x19 Stainless Steel Wire,

W i ht i i ifi t


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1.4 STRUCTURAL DESIGN

1.4.1 SUSPENDERSSuspenders transfer the loads from the deck to main cables, and are attached to crossbeamsat 2 meter intervals. Thus, with a 0,80 meter deck width, each suspender has a tributary area of2x0,4=0.8 m, Comb 1 =5,49 KN/m

2and thus must be able to carry 4.39 KN.

According manufacturer specifications for above analyzed loads and conditions,

GC16-B, GC16-BK and rope GC16-R (or equivalent) is recommended for suspenders and fittings.

GERRO COMBI Combination Rope consists of a combination of steel and fibre rope.

Steel wire strands covered with Polypropylene (PP) multifilament. Minimum tensile strength of wire: Galvanized 160 kp/mm=1570 N/mm. Different colours are available; red, blue, green, yellow, black and also

as a mix of these.


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Pedestrian Suspension Bridge1.4.2 HANDRAIL


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Pedestrian Suspension Bridge1.4.3 MAIN CABLESFor calculation of internal cable forces it was made realistic model of bridge.Bridge span is 20,7m separated into 10 parts, each part lenght is 2,07m.

Cables are wire rope

1

12mm 7x19 timber cross-beams are 100x100mm and decking plates height is 40 mm.GEOMETRY


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LOADS

Dead Load


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Wind load


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RESULTS

Comb 1: Axial force in cable


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Top suspension rope:

Max Fx1=70.83KN

7x19 steel rope

MBL - Minimum Break Load= The stress which, when steadily applied to a structural member, is just sufficientto break or rupture it. Also known as ultimate load.

SWL - Safe Working Load= Briefly defined, the 'safe working load' of a line is the load that can be applied withoutcausing any kind of damage to the wire rope. In manufacturer table above safety factor is 6.

According manufacturer specifications2

and for above analyzed loads and conditions,12mm 7x19 Stainless Steel Wire Rope (or equivivalent) is recommended for top suspension cable.


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TIMBER STRUCTURE CALCULATIONS-------------------------------------------------------------------------------------------------------------------CODE: EN 1995-1:2004/A1:2008

ANALYSIS TYPE: Member Verification-------------------------------------------------------------------------------------------------------------------CODE GROUP:MEMBER: Timber Plank-------------------------------------------------------------------------------------------------------------------LOADS:Governing Load Case: 5 COMB 1 1*1.40+2*1.60-------------------------------------------------------------------------------------------------------------------


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Pedestrian Suspension Bridge1.4.5 CROSS BEAMSFloor load: 5,49KN/m

2, Tributary area length = 2,07m

Cross beam load: 11,36 KN/m

Moments: Mmax=(q*L2)/8=11,36*1

2/8=1,42 KNm

STEEL DESIGN-------------------------------------------------------------------------------------------------------------------CODE: British Standard BS 5950:2000ANALYSIS TYPE: Member Verification-------------------------------------------------------------------------------------------------------------------CODE GROUP:MEMBER: Pedestrian bridge cross beam PFCH 100x50x10

S


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2. CONNECTIONS

2.1 TOP SUSPENSION ROPE CONCRETE COLUMN

The tensile cable force is 70,83 KN.

Anchors are compound by U shaped steel bar S235; Tensile load is dissipated to 4 bars. As-

sumption is that load dissipation is asymmetrical (ratio 2:3).

The largest computational load per pair of bars is L=70.83 x(2/3) = 47,22 KN

Steel properties: S=235 MPa=0,235 KN/mm2

Bar section area: 47,22/0,235=200,9 mm2

For anchors is recommended to install

4 steel bars (S235), diameter 14mm. Bars are prepared and fixed in right position before con-

creting of column.

P d t i S i B id


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2.2 HANDRAIL CONCRETE COLUMN



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Pedestrian Suspension Bridge2.3 BOTTOM SUSPENSION ROPE CONCRETE COLUMN



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2.5 SUSPENDERS HANDRAIL ROPE

GERRO GC16-C

2.6 SUSPENDERS - CROSS BEAMS



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3. QUANTITIES OF MATERIALS

POS DESCRIPTION UNITS TOTAL

1 Supports in concrete wall

Fittings anchored into columns

Fork tensioner wire rope assembly

pcs 6

2 Suspenders, GERRO GC16-R (or equivalent)

SL1 2,02m

SL2 1,61m

SL3 1,31m

SL4 1,15m

SL5 1,10m

pcs4 pcs

4 pcs

4 pcs

4 pcs

2 pcs

3Main Cables: 12 mm 7x19 Stainles Steel

CL1 21,08 m

CL2 20,58 m

pcs

2pcs

2pcs

4Handrails: GERRO GC16-R (or equivalent)

HL1 20,68 mpcs 2pcs



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Pedestrian Suspension Bridge4. INSTALATION METHODOLOGY


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Suspended Bridge

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