Design Manual of Suspension Bridges

7/21/2019 Design Manual of Suspension Bridges

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Volume 3: Suspended Pedestrian Bridg

Part 1: Design and Analysi

First Edion 20

Changing Lives One Bridge at a Tim



Volume 3: Suspended Part 1 Design & Analysis

ForewordBridges to Prosperity Suspended Bridge Manual

Dear User:

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tp t th Bgug Dstt Np t vw th b h susp bgsbg but by th s th. Hs pt tht fw uh pg pt by th Nps

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thgy swh Np. By th t 1990’s, th BBLL (Bug Bgs t th L Lv)

h b f th st sussfu vpt fstutu pgs th w. Th

y suss ws fw by pubshg th “Susp Sht Sp T Bg St Th

Hbk Dwgs” 2002 whh ws fw by th p f 2,500 bg Np by

2008.

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2003: Z P Chs Rs. As w xp th Hvts uty ftbg pg

t Af L A, t b ppt tht th g Hvts wgs t bvt t AutCAD, th us vt t vsu ft. Ths hgs v

t y f s f tg, but s t w th us wgs t b sy pt t h

w uty, wg f hgs tpgphy, vb sus, utu. Lk Hvts fu,

t pubsh u k ths vght. Ev wth th gus

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wys b wk pgss, g t u vw vs.

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y t . But, I wu k t spy thk Pss Bkh

(PB) f NYC f vg th Cs Dw uts t AutCAD,

th Rty Cub f Nwpt Nws, 35 th Rty Cubs th Rty

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sg t (Jy Jhs, Avy Bg, Z P, Chs Rs) tht tbut s

y hus t k ths pssb.

I th s spt tht w us t fy us th Hvts us, w hby th s. Ths

u s g b fy p stbut. W wu sk, hwv, tht y hgs

t th u t y sh wth Hvts Bgs t Pspty s tht w ght

bt, but tht yu s k y w us hgs f vb t s w.

Sy,

Kth R. Ftz, Rt &

Fu, Bgs t Pspty, I.

5007 C-126 Vty Bv.

Yktw, VA 23693

www.bgstpspty.g




Introduction

I 2003, Bgs t Pspty (B2P) st

tv t Np t t wth th Swss

gz Hvts t but

th b-susp bg thgy.

Dsg stu f th suspbg w tught t Hvts’

pph t ppty bg bug t

th uty v. Ov th pst 6 ys,

Bridges to Prosperity has introduced the

hghy t Susp

Bg sg t uts f th

thgy u th w.

Th sgs u th Vu 3

Susp Pst Bg Mu gt wth th Hvts Np Sht Sp T Bg

Th Hbk tht ws t wth v 30 ys f xp th utus gs fNp. Bgs t Pspty hs ut w th utu hgs s w hv tk

th thgy f Ethp t Pu. Th sgs hv b pt t b sut th

gv f wk. Bgs t Pspty hs stu ps xp xbty

sg tvs sg pss ts t su th susp pst bg s

y sustb p f us vyg tpgph ggph gs f th

w.

Th fu pts t Vu 3: Susp Pst Bg Mu, stutu s fws:

Part 1: Design and Material Quanes

Part 2: Construcon Plans Part 3: Construcon Guide & Quality Control

Part 4: Operaons & Maintenance

As wth y ut sg, usg ssups ust b by th g sg. Th fwg

u w pt t pv bth ut wgs f us wthut gg

sg gus f ths tst bg uss t v wth ths us. F futh sg

g ssups f th Hvts Np Sht Sp T Bg Th Hbk,

ty pt sg sts s w s y pt sg s sts.




Volume 3 Suspended Pedestrian BridgePart 1: Design and Analysis

Table of Contents

Section 1: Suspended Bridge: Design Background 1.1 Dsg Lgs Assups

1.2 Lts

Section 2: Design Procedure 2.1 Ovvw

2.2 Aby Lv Suvy

2.3 Dw p & x bg fus

2.4 St Cb Szs: Cb k-up t

2.5 Cut Rqu Nub f Ts

2.6 Fz Ps f Fus

2.7 St T & Ahs Dsgs

2.8 St Cstu Dwgs

2.9 Cp t F Dwg 2.10 Dsg Exp

Section 3: Material Estimate 3.1 Cb & Cps

3.2 St Rft B

3.3 Ct

3.4 Dkg

3.5 Oth Mts

3.6 Mt Qus Exp



Volume 3: Suspended Part 1 Design & Analysis 5

Section 1:Suspended Bridge Design Background

1.1 Design Loadings & Assumptions

Th fwg s ts bs ssups us by Bgs t Pspty wh fyg xtpg up th g bg sg. Thy t b f f -g

sgs, s sgs y pt usg th fwg s ssups. Skp t

S 2 f sg pss.

1.1.1 Liveloads

Bf stg th bg sg, vfy wth stutu g s gus. Th

Bgs t Pspty st f v s 3.11 kN/² (65 b/²). As t AASHTO (1997),

th v u f 4.07 kN/² (85 b/²) f kg s xg 400 squ ft s

sstt wth ASCE 7-95, “Mu Dsg Ls f Bugs Oth Stutus.” Th u

uts f th u pbbty f th g g f th stutu bg fuy t y

gv s sstt wth th gs xpt f typ pst bg. Tt LL = 3.11 kN/, ssug 1.0 t wth

1.1.2 Dead Loads

Th s th su f sf-wghts f th bg ts. Bw s tb f ssu szs

wghts, us B2P sg ts.

Tt DL = 0.321 kN/, ssug 1.0 t wth

1.1.3 Wind Loads (Overturning)A w pp hzty t ght g t th gtu xs f th bg sh b pp t

1.676 kN/² (35 b/²). Th sp w pssus f w vty f 100 s p hu. I

suh s st hs hgh w-vty quts: AASHTO A 3.15 (1997) y b f

th . Gv th pjt p f th bg s 1.1 ts hght: th sug

w vtu f s 1.843 kN/.

Tt WL = 1.843 kN/, ssug 1.1 t g hght




1.1.4 Load Combinaons

T ut th uuv v , h pssb b ust b hk t

th xu tg s. Th fwg bs w b us, xtt f Tb

3.22.1A AASHTO (1997):

Futh ts f sg ssups y b f S 5.

1.2 Limitations

Th susp bg s t f psts, vstk y s t pb f ssg

th 1.0 t w k wth. Wg th k up t 1.5 ts s pssb s w, but qus g vut th h, tw kg ps. It s tht y bys, s

tbks b wk

ss, but s

ptb f ssg.

Athugh th t w

gs ppy

s wth s sp,

th s sg t f 120

ts wthut

w guy stutus. Thgtu gty f th

bg s ps

by 120 ts wthut

th t suppt.

W guys sgty

s th v st f th

stutu s tw (2)

bs fu (4)

hs qu.

Th sg gu s s t t 1.0 t k wths. Isg th k wth thby ss

bth th v thf qus g t pt us. Futu

s f ths u y u gt ub f tvs Futh, f st k

s hs, th spg s s. Nt tht th g Hvts Np sg

u th st k gs thf f st k s hs, sg g s

ssy.




Section 2:Design Procedure

2.1 Overview

Dsgg th susp b bg qus vy th bkgu. Th fwgs w pv stp by stp gu t sgg bg fwg th p f th st

suvy s ut Volume 2 Feasibility & Topographic Survey .

2.2 Aby Lv Suvy

2.3 Bg p & Fx Fu Ls

2.4 Cut Rqu Nub f Ts

2.5 Fz Ps f Fus

2.6 St T & Ahs Dsgs

2.7 St Cb Szs: Cb k-up t

2.8 St Cstu Dwgs

2.9 Cp t F Dwgs2.10 Dsg Exp




2.2 Abney Level Survey

If t s y, pt bg p suvy usg Aby v. Rf Volume 2

Feasibility & Topographic Survey f pt ts.

2.3 Bridge Profile & Fix Foundation Locations

Ct p skth f th st suvy. Us pts ‘L’ ‘R’ f th suvy t k th

py f th tws f th ght s spvy. Vfy tht th

butt s th s f th bk wh fg w st, wt t ’s bk.

D pts:

• Sp ts. Nt f su btw ‘L’ ‘R’ f t -tw sp

• Hght btw ‘L’ ‘R’, f v t suvy sht

• Nt s k typ th s




2.4 Calculate Required Number of Tiers

A u s qu btw th wst pt th b th hghst pt tht

th wt hs v h (HWL). Futh, th xu hght btw th tw

tws ust b th th sp (L) v by 25, fu pt f th sp. If ∆H (th hght

btw pts ‘L’ ‘R’)) xs ths ut, f th tws s t b

s. T pv qut t quz s v btw tw ss,

ust ut th qu ub f s; h s 1.0 t t s th v f th bg

tws tt th v f th bs.

I t ut th qu hght, th fwg f ust b kw;

• Span (L) ts (ust b ss th 120 ts)

As th suvy pts ‘L’ ‘R’ v t th ft f fu t ft f fu,

stt by ssug 1.40 ts th s t u wkwy s t

wkwy s sp. O wgs st, vfy th s.

• Height dierence (∆H) = Ev ‘L’ – Ev ‘R’Stt by ssug tht h s hs , s th v f th wkwy tws

s 1.40 ts bv ‘R’ ‘L’ spvy (1.0 t f , 40 f s

pt, p th tw wg T1). Us th s v ssups

tu s us th suvy: w s fu v = 100.00.

• Cable Design Sag (Bd) and Hoisng sag (Bh) (f N-Psth Cb)

Th b sg s th v p tht th b w p bw th wkwy ss.

Th b s hst t ss sg th s sg bus th b s st, th

sf-wght f th bg t th g w sghty stth th b. As

suh, th wst pt s th sg sg, but th tu w pt tks bth t

s. Less than 80 m Greater than 80 m

5.00% x L 4.55% x L

4.00% x L 3.64% x L

• Low point ‘f’

If bth ss qu hght (∆H = 0), th th w pt s ty th .

If t, th Cut usg th fwg qu us th w pt tx th

fwg pg.




• Verify adequate Freeboard (Fb)

Fb s th qu btw th wst pt th b th

hghst pt f th wt. A g y u s th suggst fbvus wth st tpgph s, but f g pupss,

u fb qu s s fws;

- Mountainous gorges: 4.0 -5.0 meters

- Flood Plains: 2.0 meters

Fb s v by tkg th w s v, subtg th sg vu ‘f’

subtg th v f th Hgh Wt Lv. If th vu f Fb s ss

th qu, th sg ust s th ub f s th bth

fus.

Exp:

A t vy suvy wth sp f 60 ts, pt ‘L’ 2.0 ts w th pt

‘R’, Hgh Wt Lv (HWL) t v 96.5 ts f th suvy;

Low side elevaon = 101.40 meters

Low point in cable (relave to low side) ‘f’ = 2.08 meters

High Water Level (HWL) = 96.5 meters

Okay




Finalize Position of Foundations

A sg th ub f s qu, th sz f th fu ftpt s kw. Ths stp

w vfy th yut sg. If ft f fu suvy pts ‘L’ ‘R’ ust b v, tk

t t suvy t st.

• Vfy qut sp g st f sp (Volume 2 Topographic Survey )

Mxu 35 g sp s Mxu 60 g sp k

or u 3.0 ts f g or u 1.5 ts f g

• Vfy sp ss th 120 ts btw ss

• Vfy hght f tp f s (∆H) < L / 25

• Tk sp ut Dsg Sg, B. Vfy w pt ‘f’

• Cut Fb

• Vfy gt th u w

Flood Plains: 2.0 meters Mountainous gorge: 3.0 meters

Soil Rock




2.6 Select Tier & Anchor Designs

Th tw typs f h sgs; Gvty Ahs Du Ahs. Gvty Ahs y b

us y s k s thy y ‘wght’, t p v th h.

As suh, th xv qu s sb.

Du Ahs qu k s s thy y f btw th k f th pu

t u. As suh, y h ftu k s ptb. S Volume 2: Feasibility

& Topographic Survey f f.

Gvty Ah ps spt t tw subtgs; 0 - 60 t sps, 61 - 120 t

sps. Eh ss us (1), tw (2), th (3) tvs. A suy f

Gvty Ah Ps fu Volume 3 Part 2: Suspended Bridge Drawings s fws:

0 - 60 1 T Gvty Ah 1G60

0 - 60 2 T Gvty Ah 2G60

0 - 60 3 T Gvty Ah 3G60

61 - 120 1 T Gvty Ah 1G120

61 - 120 2 T Gvty Ah 2G120 61 - 120 3 T Gvty Ah 3G120

Du Ah ps s spt t tw subtgs; 0 - 60 t sps, 61 - 120 t

sps. N futh ss s s k hs t thsvs t th

. Ths s u t th sht st btw th h th ss, qu u t sp

k s. T s th ub f s wu qu t st h ppy futh bk

t th k, thus sg uty. Th th szs f u hs; s, u

g. S (0 - 40 ts) Mu (41 - 60 ts) hs u 1D60, Lg (60

-120 ts) y b fu 1D120. A suy f Du Ah Ps fu Volume 3 Part 2:

Suspended Bridge Drawings s fws:

0 - 60 1 T Du Ah Rk 1D60

61 - 120 2 T Du Ah Rk 1D120

2.7 Select Cable Sizes: Cable Look-Up Tool

Bgs t Pspty t Ms Ex Cb Lk-up T, vb t th wbst t www.

bgstpspty.g/sus.

Th Cb Lk-up T qus th us t put th bkg stgth ( f t s bkg

f) f vb b pus, bs y ub f b ub bs, utputsth xu sp wb f gv k wth. Bf usg th t, sh vb st

b qust Pf Iv stg bkg stgths f gv bs.

Th Cb Lk-up T ssus tht th b hs v g f 0.325% s t f

us wth -pstth b.




Step 1Rsh vb b bkg stgths. If pt t ts kwts (kN),

vt t pus usg th fwg shps:

Step 2

Iput Bkg Stgth vus ( pus) s ub f bs (red txt).

Step 3

Mfy bs u s k wth hs vu t st s g s bg sp (yw).

Exp:

Iput 2 wkwy bs 2 h bs. Ty g wth 4 wkwy bs 2

h bs.

Step 4

Cut quty f b. Cs th sts f sv bs f b bf vg

. O b s s by th f 500 ts, s f b qus sghty

th 500 ts, t y b wth th st t s th sz f th b t u

th ub f bs thus th tt qu gth.

Cut th quty f b t ; wh th st btw hs, wth

14 ts 4 pt gy t ut f b sg wp-bk wth th

hs. F th st vus f th Cstu Dwgs.




2.8 Select Construction Drawings

F gv sp, gg s ub f s, tw (2) Abutt T & Ah wgs

ust b st, f h s f th v. Th Tw wg ts th 1.0 t k wth

tw s qu. Th (3) Dkg wgs ust b st f th 2 4 wkwy bs,

wth tvs btw ssb s s spvy.

Abutt T & Ah (Rght L s qu)

Gravity Anchors

0 - 60 1 T 1G60

0 - 60 2 T 2G60

0 - 60 3 T 3G60

61 - 120 1 T 1G120

61 - 120 2 T 2G120

61 - 120 3 T 3G120

Rock Drum Anchors

0 - 60 1 T 1D60 61 - 120 2 T 1D120

Tw 1.0 k wth T1

Dkg P 2 wkwy bs W21

4 wkwy bs W41

Dkg S 2 wkwy bs W22

4 wkwy bs W42

Dkg DtWith Nailer

2 wkwy bs W23

4 wkwy bs wth N W43

No Nailer

2 wkwy bs N N W24

4 wkwy bs N N W44




2.9 Compile into Final Drawings

Cpt th bg sg by pg qu bg wgs g bg p f

th pjt. Iu ss ug sp, pth f h, st t th bk f th

h. St th fwg wgs;

Gravity Anchor Right Side 1G60

Gravity Anchor Le Side 1G60

Tower 1.0 k wth T1

Decking Plan W21

Decking Secon W22

Decking Detail With Nailer W23




2.10 Design Example

A p vy wth 60 t sp ws suvy. C pts f th suvy s fws:

• Pt ‘L’ Ev (w s) = 100.0 ts

• Pt ‘R’ Ev (hgh s) = 102.0 ts

• HWL = 96.5 ts

T ut th u ub f s, fy u fb (Fb) s gt th 2.0 t

u s sp f vy. Stt by ssug (1.0 t hght pus 0.4 t s

vg hght).

Span (L) = 60 ts

Elevaon low side walkway saddle =

Elevaon high side walkway saddle =

Height dierence (∆H) =

Verify:

Cable Design Sag (Bd)

Low point ‘f’

Css f sp ∆H Dsg Sg Ev Cht = 2.08 ts




Verify Freeboard ‘Fb’

Select Cable

Th b supp pv sps f 26 IWRC b wth bkg stgth f

30.0 t ts (68,343 pus). Usg th Cb Lk-up T, 4 wkwy k bs 2

h bs qu, s thy sut t 64 t sp.

Select Drawings

O , 60 ts ss Rght butt = 1G60O , 60 ts ss L butt = 1G60

Tw Dwg= T1

Dkg P, 4 b = W41

Dkg S, 4 b = W42

Dkg Dts, 4 b N = W43

Compile into Final Drawing




Section 3:Material Estimate

3.1 Cable & Clamps

St st b bs th t bkg stgths, usg th Cb Lk-up T www.bgstpspty.g/sus. A sg th pu b, ut th quty

t by upyg th ub f bs by th fwg qu:

Th quty f ps p b s pt th sz f th b th typ f p st.

Th tb bw s th Bgs t Pspty st f tqu quts f p-fg

b b ps t gv b p ts. Cb p uftu pv

sps tht ust b v s ths ht s y gv s gu.

Drop-forged clamps are of superior quality and must be purchased whenever possible.




3.2 Steel Reinforcement Bar

Towers

- 4 ps st b, 16 x 4.50 ts gth

- (# f wkwy bs + 2) ps, 16 x 20

Decking Suspenders

- (Tw th (Sp + 1) ps), 8 sth, ut t 1.80

Gravity Anchors

- Sps 60 ts ss (S Mu)

- 4 ps st b, 20 , 2.90 gth;

- 11 squ gs, 10 , ut t 2.20 h,

bt t squs 0.50 p s

- Sps 61 -120 ts (Lg)

- 8 stght bs, 20 , 2.90 gth;

- 11 squ gs, 10 , ut t 3.35 h,bt t squs 0.80 p s

Rock Drum Anchors

- Sps 40 ts ss**

- Ah s, 16 ps, 25 , ut t 1.50 ts

- I u: 8 ps, 10 , ut t 3.40 ts, bt t 0.90 t

- Out u: 8 ps, 10 , ut t 5.25 ts, bt t 1.50 t

- Sps 41 - 60 ts

- Ah s, 20 ps, 25 , ut t 1.50 ts

- I u: 8 ps, 10 , ut t 4.15 ts, bt t 1.15 t t- Out u: 8 ps, 10 , ut t 5.90 ts, bt t 1.70 t t

- Sps 61 - 120 ts

- Ah s, 40 ps, 25 , ut t 1.50 ts

- I u: 8 ps, 10 , ut t 4.15 ts, bt t 1.15 t t

- Out u: 8 ps, 10 , ut t 5.90 ts, bt t 1.70 t t

3.3 Cement

Qus gv wgs. Su tgth th qus f T & Ah wgs f bth L

Rght butt th quty f th Tws.

If t s t b us t xpt th ug , tk t t th v 28 y stgth

u . It s t th s f f h pus. Th quty qu

s sp th put.




3.4 Decking

Bgs t Pspty hss t us w kg wh v w s vb p. Th

tw typs f w kg tvs: wth wthut ‘’. Th ‘’ s th s wth s

th kg ps, s h t th tp f th w ss-b t s th ut f

suf vb f g th kg ps. Th ‘’ pvs stutbty ws

f s ssb sz but ss th tt gth f kg ps qu. It s up t th

sg g t f th st s wt.

Dkg ps ut t 3.0 ts f y sp v 60 ts pfby sps. If th bg

s sht th 60 t sp, 2.0 t kg ps wb. Th tt ub f kg

ps s qu t [sp v by gth f h b (th 2.0 3.0)] up by v (5), s

th w b v kg ps ss, h 15 - 25 w. If ‘s’ t b us,

(Sp pus ) ts f kg ps w b qu, ut t 1.0 ts.

Cssbs: (Sp + 1)

Dkg: (Sp / gth f h b (th 2.0 3.0) x 5)

Ns (p): (Sp + 1)

3.5 Other Materials

• Fxb Ps tubg: 5 t* 3.5 t p b (Ah)

• Fxb Ps tubg: 5 t* 2.0 t p b (Tw)

• Tyg W 10 kg

• Ns: 5” 1 kg p t

• U-s 1 kg p 10 ts

• Sws: 5/16 x 10 (4”) 1 p k p

• A-sv pt 1 g (3.8 L) p 50 ts

• Fg: 1.50 hgh Bg sp x 2

• Rg T 4 gs• H Ss 4 ps

• Pt f tws 6 gs

• S/Gv

• Msy Bk

* The best product for this purpose is reinforced sucon tube used by water trucks.

Nailer (Recommended) No Nailer




3.6 Material Quantities Example



Bridge Name:

Span:

Material List

All prices are estimations, prices can change at moment of purchase, always verify

Item Unit Units required Estimated Unit Price

Cable and clamps

Cable 26mm m

Clamps 26mm piece

Cable 32mm m

Clamps 32mm piece

-$

Construction MaterialsCement (6.4 x volume for concrete, 1.1 x area for mortar) bags of 40kg

Concrete Blocks = 40 x 20 x 15 (cm) unit

Rebar 12mm (1/2") (9m)

Rebar 16mm (5/8") (9m)Rebar 20mm (3/4") (9m)

Rebar 25mm (1") (9m)

Handrail saddles unit

Walkway saddles - 2 cable unit

Walkway saddles- 4 cables unit

Tying wire kg

Plastic suction tube 3" mts

Roofing Tar gal-$

Deck

Wood crossbeams - (10cm x 10cm) x 140cm piece

Wood nailing panels - (5cm x 20cm) x 100cm piece

Wood crossbeams - (10cm x 20cm) x 140cm piece

Wood platform - (5cm x 20cm) x 200cm piece

Screw - 8mm x 10cm(nailing panel to crossbeam connection) unit

Nails - 15cm kg

Smooth iron bar 10mm (5/16") (suspenders) (9m)

Smooth iron bar 12mm (1/2") (j-bolts) unit

Anti-rust paint (suspenders) 0.5gal Anti-rust paint (j-bolts) 0.5gal

Safety fencing = 1.5m in height mts

U-shaped nails kg

Tying wire kg

-$

Local Materials

Sand m³

Gravel m³

River rock m³

Dressed Stone m³

-$

Transportation

Transportation of materials (City - City) per trip

Transportation of materials (City - Village) per trip

Transportation of materials (Village to site) per trip-$

Misc. Tools and Tool Rental

Misc. Tools* (listed below)

Tool rental (winch and/or drill)-$

Labor and Technical Support

Mason daily

Carpenter daily

Supervision dailyLogistical Support per visit

Logistical Support per visit

Estimated Sub-total for Labor -$

Total -$

Contingency 10% -$

Total with 10% Contingency -$

Bridge Location:

Documents

Design Manual of Suspension Bridges