Gumjae Bridge - Extradosed Bridge Parametric Study

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Modeling, Integrated Design & Analysis Software

Extradosed Bridge Design and Construction Construction Naga Ravi Kiran MIDAS Information Technology Technology Co., Ltd.

Structural Engineering Seminar

Contents

1

Extra Dosed Bridge – A Introduction

2

Gyumjae Bridge Project


Introduction

Cable Stayed Bridge

Extradosed Bridge

What is the difference?


Introduction

Tension Tension Prestress Compression Cable Stayed Bridge

Compression Extradosed Bridge


Structural Behavior

Cable Stayed Bridge

Extradosed Bridge

Stay cables cables ve verr ti call y support support the gir de derr l ik e

Ex tr ados adose ed cab cabll es tr ans ansmi mi t longitu lon gitu din al f orce

el as asti ti c bear bearii ngs to th the e gi girr de der r

to the gi gi r de derr l i ke pos post-tens t-tensii oni ng tendons wi with th verr y lar ge ecce ve ccent ntrr i cit citii es.


Design Criteria for Geometry



Span by depth ratio: L/hc = 30-35



Span by tower height ratio: L/Ht = 15



Side span to main span ratio: L1/L = 0.6-0.8



Cable arrangement: Semi-fan or harp cable arrangement


Advantages

uitab ble fo forr spans of 100-2 -20 00 m  Suita nee ed for diap iaphrag hragms ms at anc ncho horag rage e loc loca atio tions ns  No ne Use e of norma normall pre pres stre tres ssing anc anchorag horage es  Us nee ed for te tend ndo on ad adjus justm tme ent  No ne malle llerr stre tres ss cha hang nge e in cable bles s due to live loa load ds  Sma

ompa pac ct py pylons lons  M ore com Les ss cha hang nge es in de dec ck de defle flec ctio tion n du during ring con ons struc tructio tion n by Bala Balanc nce ed Ca Cantile ntilev ver M etho thod d  Le implif lif ie ied d con ons struc tructio tion n due to Lowe Lowerr he height ight of pylons lons..  Simp


Analysis Procedure Analysis for an Extradosed bridge is done in 2 steps:

1. Pre Prelimi liminary nary analys analysis is to find cable cable forces forces or Final Final Stage Stage Anal Analysis: ysis: a) Full Mode Modeling ling witho without ut Cons Construc truction tion stag stages es b) Sim Simple ple lin linea earr stat static ic anal analysi ysiss c) Calc Calculat ulation ion of Unkno Unknown wn Load Load factors factors for for Initia Initiall Cable Cable force. force.

2. Des Design ign Stag Stagee Const Constru ructi ction on Ana Analys lysis: is: a) Full mode modell along along with the Cons Construc truction tion stag stages es b) Appl Applicat ication ion of Initia Initiall Cable Cable pre pretens tension ion c) Co Cons nstr truc ucti tion on Sta Stage ge analysis d) Ti Time me depend dependen entt Materia Materiall Anal Analysi ysiss


Analysis Procedure Final Stage Analysis: The starting point for design of a cable stayed bridge is an idealised stressed stat e at a given time 

This is defined as the “Final Stage”

Static and Dynamic analyses

The construction sequence and cable

and section design are

installation forces are developed such

---------undertaken --------undertaken using th

that the final stage is achieved at the

e final stage

given time


Analysis Procedure 

Cable bridges are highly redundant structures •

This gives the designer flexibility to prescribe a set of cable forces that will achieve a preferred final stressed state for the deck, pylons and cables under a given loading condition (dead + SDL)

Instantaneous Dead Load

Instantaneous Dead Load + Cable Prestress Forces

Deflection

Deflection

Deck Moment Distribution

Deck Moment Distribution


Analysis Procedure Design Stage Construction Analysis: Analysis: •Objectives of design stage construction analysis •

To determine the forces in the cable stays at each construction stage

•

Check stresses in the girder, girder, pylon and cables at each construction stage

•

Check deformations of the structure at each construction stage

Arrive at the design design final stage condition •Assumptions •Adopt an assumed construction sequence •Assumed construction loading and ambient conditions


Contents

1

Introduction to Extra Dosed Bridge

2

Gyumjae Bridge Project


2. Project outline Name

Location

Gyumjae Bridge Basic Design of Construction [Developed by: Seoul Department of Transportation]



The Bridge is located between the three way of Hweekyung Middle and High

School of Dongdaemungu Hweekyung dong, and four way of Junglanggu Myunmok dong Dong 2 Street. Goal



Construction of a Bridge and Highway to connecting Dong Dae Moon Gu Hwui

gyung dong and Jung Lang Gu Myun Mok Dong and deal with the expected development and traffic flow with Mang Woo Woo Ro, Sa Ga Jung Gil, Gil , Dong 2 Ro, Ha Chun Ro, and etc. Construction scale



Construction scale - Total span: 1,085M - Bridge Length : 393M Across length of Jung-lang stream: Width 24M, Total Total Length 225M Connecting bridge: Width 15M, Length 168M - Expansion Expansion of road: Width Width 30M, Length Length 692M


3. Project Location

Total To tal L ength: L =108 =1085m 5m Road expansion: expansion: B=30m, L =692m M ain Br idge idge:: B=24m, L=225m L=225m Connection Conne ction Br idge idge:: B=15m, L=168m


4. Structure of Steel Arch Bridge Transverse Section P l a n

S e c t i o n

◎ Bridge Dimension D i s c u s s i o n

L = 40.0 + 140.0 + 40.0 = 220.0m, B = Nielsen Arch : 24.9m  Interference between the bicycle path and pier  Irregular span ratio of the main a nd the connected Bridge (1:3.5:1)  Lack of originality since Ihwa Bridge which is preliminary designed has the same structure

Estimated cost of Construction Budget assumed : $19.87 Million (Nielsen Arch : $4500/㎡ $4500/ ㎡) Underestimated Construction budget at preliminary design $13.54 Million (Arch : $3200/㎡ $3200/ ㎡)


4. Structure of Extradosed Bridge Transverse Section P l a n

S e c t i o n

◎ Bridge Dimensions D i s c u s s i o n

Estimated cost of Construction

L = 60.0 + 105.0 + 60.0 = 225.0m, 225.0m, B=23.74m

About $18.16 Million 

The form as an Extrodosed Bridge will be the first trial in Seoul but has been imported actively recently  Maximizing the wide open view for the users by locating the Mai n tower and Cables in the center

(Unit Construction Construction cost: $3400/㎡ $3400/㎡)

Structural Engineering Seminar EXTRADOSED Bridge with main tower, 3 span

P r e l i m i n a r y D e s i g n

Cable arrangements

FAN arrangement Harp arrangement

Number of Cables 7 lines on one side (0.6”-27) (0.6”-27) (0.6”-29) (0.6”-29) (0.6”-31) (0.6”-31)

Main Tower Height

Section

Optimum Design of Bridge arrangement:: Cable arrangement

H=10,12,14m

L=105.0m (L/8~L/12)

Uniformed section

FAN arrangement arrangement

H=2.5m

Number er Numb

L=105.0m

Heightt Heigh

(L/30~L/60)

Section: Section:

of Cable Cables: s: 7 line liness (0.6 (0.6”-29EA)

of the the Main Main Towe Tower: r: H=12.0m H=12.0m (L/8.75) (L/8.75) Uniformed Uniformed Section Section 2.5m(L/40) 2.5m(L/40)


Bird’s eye view


Driver’s eye view


Side Perspective

Transverse section – section – M Main Bridge

Transverse section – Connected – Connected Bridge


5. Construction Method 1) Construction method of EXTRADOSED PSC BOX GIRDER Bridge The current construction methods of Extradosed PSC BOX Girder Bridges can be categorized in FSM (Full Staging Method) or BCM (Balanced Cantilever Method).

Construction Method

F.S.M

Full Staging Method

B.C.M

Balanced Cantilever Method

Characteristics Characteristics of the Construction Method Name

Restrictions

F.S.M

B.C.M

Duration

Economic

Constructability

Restrictions by the bottom Construction is fast due to conditions are crucial, the lumped pouring method. depending on the supporting system. Restricted by Weather

Economical efficiency is There are plenty of domestic determined by the height of the bridges constructed by this method. supporting. Easy to construct Lower pier is more cost-effective

Less restrictions by the bottom condition, weather, and environment

Cost-effective if higher pier or if there is limited space underneath the bridge. For instance, bridge over rail road, bridge over the sea.

Slow construction due to forward construction stage method

Construction management is complicated due to having measurements of each stage. Similar construction of each stage will increase the skill to construct another stage.


1) F.S.M F.S.M construction (1/2)

Introduction The F.S.M. construction applied for P.S.C Box Girder bridge is a method continuously pouring concrete on site. The method installs supports for the entire area till concrete gains its proper strength. The supports are intended to uphold temporarily the self weight of the concrete, concrete forms, and workbenches.

Characteristics Low cost of equipment, simple method of construction Cost effective for level ground and low bridges Fast construction, stable supports during construction Mostly used for PSC BOX Girder bridge

Classification

Fully supported

Partially supported

Girder Supported


1) F.S.M F.S.M construction (2/2)

The order of Construction Install supports

Install platform

Pouring concrete and cure

Install concrete form

Pre-stressing

Install Reinforcement, P.S steel

Grouting

Remove concrete form

Remove supports


2) B.C.M Construction (1/2) Introduction B.C.M construction applied for the P.S.C. Box Girder Bridge is a method method pouring concrete on site for each segment. The bridge construction is started with the construction of the cap of the pier and followed by forming forming segments of the bridge by using a special device named Form Traveler.

Characteristics Little effect of supporting conditions Possible for constructing long suspension bridge without heavy duty equipment Less weather effect Accuracy of the construction can be enhanced by the correction of errors at each construction stage. Precise construction and management needed due to changes in the structural system by each construction stage. High construction fee compared with F.S.M

Considerations Since the creep and shrinkage of concrete and the relaxation of the reinforcement reinforcement are considered, the follows should be taken into consideration.

Continuous arrangements of Sheath which places the reinforcement Accurate calculation of friction loss and CAMBER management for each construction stage Disperse of the stress applied to reinforcement connections Secondary stress due to creep and shrinkage of concrete If the assumptions change during construction, design should also change with reflecting Feed-Back to construction.


2) B.C.M Construction (2/2) Order of Construction Start of Construction Construct supports Assemble Construction Form Assemble reinforcement Assemble Sheath pipe Pouring/curing concrete

Completion of successive support construction Construct pier, temporary supporting system and the main tower Construction of SEGMENT Construction of side-span support

Tension of reinforcement Grouting

Assembling Construction vehicle (F/T)

Move and re-construct the form traveler Completion of the 1st span / move the form traveler Construct the connection Water proof of bridge surface Finish

t a e p e r

t a e p e r


6. Structural analysis of each construction method

1) Analysis of each construction based on Elastic Link (Compression (Compression only) of midas Civil

Approach 

Examine the principle role of Elastic Link (Compression Only) for midas Civil construction stage

analysis by using a simple example of Prestress Concrete structure with temporary support

Principle 

Explaining statically indeterminate structure with displacement method



Compression Only stiffness of the Elastic Link is the total force of Compression only added by

each construction stage


1) Analysis theory of each construction stage (1/5)

10.000



S A

0 5 8 0 5 1

M

The problem includes successive

construction model for P.S.C structure by FSM, which contains 10m beam, eccentric distance 350mm, and constant Prestressed

P

Force applied.

L E

M o d eling 

M O

K1

K2

K3

K4

K5

K6

K7

K8

K9

E las tic L in k (C (C o m p res sio n O n ly)

E

the supports as Elastic Link Boundary Conditions (Com (Compress pression ion Only K=∞) 

D

Mode Modeli ling ng is base based d on midas idas Civi ivil apply pplyin ing g

Compression Only is the total moment

when Dead Load and Prestressed Force D ead Lo ad & P restr estressed Fo rce Lo ad ing

L

Loading is applied as compressive condition is effective and the tension boundary

K3 K4 K5 K6 K7 E ffe c tive E la sti stic L in k (C (C o m p re ssio n O n ly)

condition is excluded. [ K3=K4=K5=K6=K7=∞ )



D ead Lo ad & P restr estressed F orce orce Lo ading ading

S A

Δ

M P

Δ

1

Analysis : Apply displacement method



Calculate the displacement Δ1 of the

statically determinate structure with the total

1 = D isplacem ent of D ead & P restr estrssed F orce orce L oa ding = K no w n value ( D isplacem ent of D eter eterm m ina te B eam )

L



of Dead & Prestressed Force Loading.

E

Δ

Calculate

springs

reaction

force

by

calcul calculati ating ng the displa displacem cement ent of Indet Indeter ermi minat natee

M O



2

F3 Δ

F4

F5

F6

F7

Force

2 = D isplace splace m en t of Ind etd etd erm erm inte nte F orce orce L oa ding ding

calculated

= f(F i) F un cti ctio n o f F i(in d eter eterm m in ate ate Fo rce )

D

 Δ

to t Δ

1 -

2

1

to t =

Δ

to t = f(K /F i) : F u n c tio n o f F i & K (stiffn es s o f sp rin g fo r b en ts)

Δ

the

indicated

displacement as

function

Unknown reaction force is analyzed by

calculating the secondary Indeterminate Δ

Δ

Δ

are

and

F3~F7. Δ2 = f(Fi)

E L

Loading,

2

Force (Fi) which occurs due to the mean displacements (Δtot=Δ1 (Δtot=Δ1--Δ2, Δtot=(K/Fi) ) of each springs (K3~K7)



S

10.000

1.500

A M P L

0 5 8 0 5 1

E

A p=

Φ

0 5 8 0 5 1

12.712.7- 3EA

F S M Tendon1

M O D E L Model that applied Elastic Link (Compression only) to each temporary support


1) Analysis Analysis theory of each construction stage (4/5)

D E A

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

8 . 3 -

D

1 4 25 0 (Stres s )

142 5 0(St res s)

+ P T

M O M E

-13.526

-13.526 -5.000

0 8 . 97

0.892

- 0.3 05

- 0.3 05

0. 0. 892

0.897

MIDAS/Civil POST-PROCESSOR


BEAM DIAGRAM

BEAM DIAGRAM

MOMENT-y

MOMENT-y

8.97181e-001

2.98548e+000

0.00000e+000

2.47056e+000

-1.72517e+000

1.95564e+000

-3.03634e+000

1.44073e+000

-4.34752e+000

9.25809e-001

-5.65869e+000

4.10892e-001

-6.96987e+000

0.00000e+000

-8.28104e+000

-6.18942e-001

-9.59221e+000

-1.13386e+000

-2.679

-5.000

-2.679

-1.09034e+001

-2.679 -0 -0. 45 3

- 0. 45 3

-2.679

-1.64878e+000

2.857

-1.22146e+001

N

2.857 2.985

-1.35257e+001

T

-2.67861e+000

STAGE:CS1 CS: Summation Last Step

STAGE:CS1 CS: Dead Load Last Step

MAX : 8 MIN : 1

MAX : 9 MIN : 7

FILE: PSC BEAM-B~

FILE: PSC BEAM-B~

UNIT:

UNIT:

tonf·m

DATE: 11/09/2005

Moment Summation

tonf·m

DATE: 11/09/2005

VIEW-DIRECTION

(1)

-2.16369e+000

2.985

VIEW-DIRECTION

X: 0.000

X: 0.000

Y:-1.000

Y:-1.000

Z: 0.000

Z: 0.000

Dead Load Moment


1) Analysis Analysis theory of each construction stage (5/5)

M O M - 13 5 . 26

E

-13 .5 26

-13 .52 6

-1 3. 52 6

- 13. 52 6

- 13. 52 6

- 13. 52 6

-1 3.5 26

-1 3. 526

-13 .5 26



BEAM DIAGRAM

BEAM DIAGRAM

MOMENT-y

MOMENT-y

-1.35257e+001

1.70065e+001

-1.35257e+001

1.54604e+001

-1.35257e+001

1.39144e+001

-1.35257e+001

1.23683e+001

-1.35257e+001

1.08223e+001

-1.35257e+001

9.27625e+000

-1.35257e+001

7.73021e+000

-1.35257e+001

6.18416e+000

-1.35257e+001 -1.35257e+001

4.63812e+000 5.669

5.669 11.338 17.006

-1.35257e+001

N

17.006

13 13. 73 2

1 3. 73 2

3.09208e+000

11.338 17.006

17.006

1.54604e+000

-1.35257e+001

T

0.00000e+000

STAGE:CS1 CS: Tendon Prima~ Last Step

STAGE:CS1 CS: Tendon Secon~ Last Step

MAX : 1 MIN : 1

MAX : 3 MIN : 1

FILE: PSC BEAM-B~

FILE: PSC BEAM-B~

UNIT:

UNIT:

tonf·m

DATE: 11/09/2005

(2)

tonf·m

DATE: 11/09/2005 VIEW-DIRECTION

VIEW-DIRECTION X: 0.000

X: 0.000

Y:-1.000

Y:-1.000

Z: 0.000

Z: 0.000

Tendon Primary Moment

Tendon Secondary Moment

Axial Load of Springs (ton) Summation

Dead

Tendon Primary

Tendon Secondary

F3

-1.68

-10.62

0

8.94

F4

-4.74

-1.65

0

-3.09

+ Tension (tonf)

F5

-3.86

-3.5

0

-0.36

- Compressio Compression n (tonf)

F6

-4.74

-1.65

0

-3.09

F7

-1.68

-10.62

0

8.94

Remarks

F1, F2, F8, F9 are excluded


2) FSM construction stage analysis (1/4)

Steps of Construction 종 단 면 도 Profile

STEP 휘경여중고

74.500m

면목역

74.500m

1 단계

H.W.L17.05

1

A1

16.000m

15.000

동부간선도로 (B=14.0X4.7m)

휘경여중고

P1

74.500m

75.000m

A2


P2

면목역

74.500m

(1단계 타설)

(1단계 타설)

2 단계

2

A1

16.000m

15.000


휘경여중고

P1

74.500m

75.000m

(1단계 타설)

(2단계 타설)

A2


P2

면목역

74.500m (1단계 타설)

3 단계

3

A1

16.000m


15.000 P1

60.000m

P2

105.000m

A2


60.000m

Py lon1

P yl on1

휘경여중고

면목역

4 단계 4 A1

16.000m


15.000 P1

60.000m

P2

105.000m

A2


60.000m

휘경여중고

면목역

5 5단계

H.W.L17.05 A1


P1

P2


A2



Structural Analysis of each construction stage using MIDAS CIVIL

1st Construction Stage: Model and activate side span temporary supports by Elastic link and Support

2nd Construction Stage: Remove Remove side span temp. supports, and activate temp. supports of main span

3rd Construction Stage : Activate the main tower and place the diagonal tension-cables in order



Structural Analysis of each construction stage using Midas Civil

4th Construction Stage: Complete diagonal Tension Tension Cables, and remove temp. supports of main span

5th Construction Stage : Pavement and Finishing => Completion of Construction

Design Condition ① Structure Structure:: 3 span continuous continuous EXTRADOSE EXTRADOSED D P.S.C BOX BOX Bridge

② Grade: Excellent

③ Dimensions: L = 60.0 + 105.0 + 60.0 = 225.0 225.0 m ③ Bridge Width: B = 23.740 m (4 lanes both way) ⑤ Thickness: H = 2.50 2.50 m (equal (equal section) ⑦ Plane surface alignment: R = ∞

⑥ Inclination: S = ( ±) 0.5 % ⑧ Construction method: F.S.M (Full Staging Staging Method Method )

⑨ Prestress Prestress construct construction: ion: Post-Tensio Post-Tensioning ning Method


2) FSM construction stage analysis (4/4) Upper Combined Stress (Mpa) 

Allowa Allowable ble Tensile ensile Stress Stress:: 3.20 Mp 3.20 Mpaa Maxi Maximu mum m Tensi ensile le Stre Stress ss:: 0.24 0. 24 Mp Mpaa  Allo Allowa wabl blee Comp Compre ress ssio ion n Stress: -16.00 -16 .00 Mpa Maximum Compressi ssion Stress: -10.10 -10 .10 Mpa

Lower Combined Stress (Mpa) 

Allowa Allowable ble Tensile ensile Stress Stress:: 3.20 3. 20 Mp Mpaa Maxi Maximu mum m Tensi ensile le Stre Stress ss:: 0.88 0. 88 Mp Mpaa  Allo Allowa wabl blee Comp Compre ress ssio ion n Stress: -16.00 -16 .00 Mpa Maximum Compressi ssion Stress: -11.7 -1 1.75 5 Mpa


3) BCM Construction Stage Analysis (2/4)

Structural Analysis of each construction stage using Midas Civil

1st Construction Stage: Construct Main Pier and Pylon

`

2nd ~9th Construction Stage: Employ F/T Seg. Construct Diagonal cables

10th Construction Stage: FSM construction for Side Span and apply Pylon1girder Time Time Load as 255 days


7. Economical Analysis F. S. M

B. C. M

Equipment

Time

Construction time of temp. supports for Side-Span

20 days

Maintenance time of temp. supports for Side-Span

14 days

Maintenance time of temp. supports for Side-Span & Main Span Maintenance time of temp. supports for Main Span

21 days

Equipment 8Seg.

Equipment, Maintenance & Operation time

Cost

Net Construction Cost

×

Time

15 days (Time per each Seg.)

120 days

Side Span Key Seg. Connection

30 days

Main Span Key Seg. Connection

30 days

21 days

Maintenance time of temp. support placed in water

2.5 months

F/T Operation time

6 months

Quantity

Cost

Quantity

Cost

Temp. support

13M (USD)

1

1.2M (USD)

F/T(4 vehicle of 2 group)

1

1.8M

Set up, pull down (twice)

1

0.3M

Operation Cost

35 Seg.

0.05M

Camber

35 times

0.15M

14.1M (USD)


8. Conclusion 

Comparison and analysis of applicative and efficiency B.C.M. with F.S.M. F.S.M. is cost effective, easier to construct, structurally conservative than B.C.M.



For considering restrictions of lower part of o f F.S.M., F.S.M., midas Civil uses Elastic Link-Compression Link -Compression only function to

analyze each construction stage and optimizes the temporary support usage plan 

Analyzed for the considerations of constructing Gyumjae bridge which is co nstruction above Junglang river,

construction over east-west highway, highway, flood control.

Comparison and summary summary of analysis of F.S.M. and B.C.M.

using equal section height of 2.5m Extradosed Bridge.

Cost effective

Construction



For For appl applyi ying ng F.S.M .S.M.. ther theree has has been been 10% 10% redu reduct ctio ion n of the the cons constr truc ucti tion on Cost Cost..



B.C.M .C.M has has a long long term erm of con constr struct uction ion since nce it requi equire ress accu accurracy of manag anagin ing g Cam Camber ber and and

severa severall Seg. Constr Construct uction ion stage. stage. 

Appl Applyi ying ng F.S.M .S.M work workab abil ilit ity y incr increa ease sess and cons constr truc ucti tion on time time can can redu reduce ce


Structural analysis comparison(1/9 )

B.C.M: Maximum negative moment on supports are relatively greater than Maximum positive moment moment in the middle point. The moments moments are concentrated to the supports. F.S.M: The moment of the supports and the middle point are relatively balanced. 

Dead Load

Moment after 10,000 days Method

Dead

F. S. M

B. C. M

`

Load

Mid-point

255,900 kN-m

22,540 kN-m

Support

-384,800 kN-m

-531,500 kN-m


Structural analysis comparison(2/9)



Cable Force

Reac Reacti tion on forc forcee of the the mome moment nt forc forcee due due to Dead Dead load load

Since

on B.C.M posit sitive ive moment does not occur for diagonal cable forces and the res resista stance force of

cant cantil ilev ever er beam beam dead dead load load is requ requir ired ed,, the the stre stress ss dist distri ribu buti tion on to diag diagon onal al cabl cables es can can be high higher er than than F.S.M .S.M..


Cable

F. S. M

B. C. M

`

Force

Mid-Point

-212,000 kN-m

Support

297,900 kN-m

0 kN-m 449,900 kN-m



Positive

Dead + Cable

moment of B.C.M is twice smaller than Positive moment of F.S.M

 Negative

moment moment also occurs very small small and B.C.M shows profitable profitable stress distribution.


DEAD +

F. S. M

B. C. M

`

CABLE

Mid-Point

48,840 kN-m

27,560 kN-m [56.4%]

Support

-86,890 kN-m

-81,540 kN-m [93.8%]



For B.C.M construction Cantilever Tendon Tendon is added on the upper part to resist excessive negative moment. (Efficient to place internal tendon especially bottom tendon) F.S.M. construction it is difficult to place certain tendon at the negative and positive moment.  For F.S.M.  Comparing the sum of moment BC.M. shows more efficient aspect on Positive and Negative moment . 

Tendon Primary


F. S. M

B. C. M

Tendon Primary

Mid-Point

-70,400 kN-m

Total : -21,560 kN-m

-57,830 kN-m

Support

62,950 kN-m


80,620 kN-m

Total : -30,270 kN-m Total :

-920 kN-m





Tendon Secondary

Tendon Secondary Moment is decided by placement and the amo amount of tendon. F.S.M.

show showss effi effici cien ency cy in both both posi positi tive ve and and negat negativ ivee mome moment. nt. 

Howe Howeve verr, in the the tota totall sum sum B.C. B.C.M. M. show showss effi effici cienc ency y in anal analys ysis is..


F. S. M

B. C. M

Tendon Secondary

Mid-Point

33,390 kN-m

Total : 11,830 kN-m

Support

23,200 kN-m

Total :

-40 kN-m

38,940 kN-m

Total :

8,670 kN-m

5,500 kN-m

Total :

4,580 kN-m



Creep Secondary



Cree Creep p Seco Second ndar ary y Mom Moment ent beha behave vess sim similar ilar to the the case case of Dead Dead Load Load..



In the tota otal sum sum of posit ositiive momen omentt B.C. B.C.M M. show hows eff efficie icienc ncy y but but, in the nega negattive ive momen omentt

sinc sincee the the Cree Creep p Seco Seconda ndary ry acts acts F.S.M .S.M.. show show effi effici cienc ency y.


F. S. M

B. C. M

Creep Secondary

Mid-Point

4,639 kN-m

Total : 16,469 kN-m

Support

-16,950 kN-m


0 kN-m -35,730 kN-m

Total :

8,670 kN-m






Shri Shrinka nkage ge Seco Seconda ndary ry Mome Moment nt show showss simi simila lari rity ty in both both meth method. od.

Shrinkage



Similar to Creep Secondary moment the total sum of positive moment B.C.M. shows

Secondary

efficiency but, in the negat gative moment since the Shrinkage Secondar dary acts F.S.M. show efficiency. Moment after 10,000 days

Method

F. S. M

B. C. M

Shrinkage Secondary

Mid-point

9,980 kN-m

Total : 26,449 kN-m

9,177 Kn-m

Support

-13,230 kN-m


-15,060 Kn-m

Total :

17,847 kN-m




Str Structu uctura rall anal nalysis sis show hows that hat on the final inal com combina binattion both oth Met Method hod of cons consttruct uction has has similar similar results. results. Forr str stress ess as aspe pect ct F.S .S.M .M.. sho shows ws gr grea eater ter an and d co cons nser erva vati tive. ve. Ho Howe weve verr si sinc ncee th thee pl plac acem emen entt  Fo of Con onti tinu nuit ity y Ten endo don n is fu func ncti tion oneed to grea eate terr se seccti tion on for orce ce,, it is in inef effi ficcie ien nt fo forr pl plac acin ing g tendon. 

Conclusion of Stress analysis

Special Loads (D + CF + LI + PS1 + PS2 + CRSH2 + SD) Method

Upper limit stress (MPa)

Bottom limit stress (MPa)

F. S. M

B. C. M


Structural analysis comparison(9/9 )

Diagonal stress



The The resu result ltss of equa equall lly y sect sectio ione ned d (H=2 (H=2.5 .5m m) and and 7 (0.6 (0.6””-29E -29EA) A) diag diagona onall cabl cables es plac placed ed show showss

that B.C.M. contains construction stages that exceed the allowable stress and becomes

of each

cons conser ervat vativ ivee at the the final final stage stage.. Construction stage



Ther Theref efor oree for for equa equall sect sectio ion, n, diag diagon onal al force orce is grea greate terr in B.C. B.C.M. M. and and beco becom mes cons conser erva vati tive ve

after constructi constructing ng continuous continuous

Method

Forr ap Fo apply plyin ing g B. B.C. C.M M va varin ring g sec sectio tion n is mo more re ef effic ficien ient. t.

F. S. M

B. C. M 4800.0

4800.0 4600.0

4600.0

허용응력

허용응력

PY-1 Mid-span Diagonal

4400.0

C8

) N k ( 4200.0

C9

력 4000.0 장 재3800.0 사

C10

3600.0

C13

C11 C12

C8

) N k 4200.0 (

C9

력 4000.0 장 재3800.0 사

C10

3600.0

C13

C11 C12

C14 3400.0

Stress

4400.0

C14 3400.0

3200.0

3200.0

계 계 계 계 계 계 계 계 계 계 계 계 단 단 단 단 단 단 단 단 단 단 단 단 1 2 3 1 2 3 4 5 6 4 5 공 3 3 3 3 3 3 완

계 계 계 계 계 계 계 계 계 계 계 계 계 단 단 단 단 단 단 단 단 단 단 단 단 단 1 2 3 4 5 6 7 8 9 0 1 2 공 1 1 1 완

시공단계

시공단계

Construction

Allowable ble

Max: 4,221k 21kN Min: 3,5 3,554kN

Allowable

Max: 4,746kN Min: 3,687kN

Finish

4,585 kN


4,585 kN


Q&A

Gumjae Bridge - Extradosed Bridge Parametric Study

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