Cablestayed Bridge
Short Description
Cablestayed Bridge...
Description
UNIVERSITY OF NIŠ Faculty of Civil Engineering and Architecture
Design and Calculation of Cable-Stayed Bridge Diploma Thesis
Ana Spasojević
Task Design a pedestrian concrete bridge over the river Nišava in Niš, according to the conditions defined by: – cross section of the regulated river channel (waterways) – site plan (location plan) – technical solution for the bridge substructure
Technical data: – – – –
span of the bridge: 70.0 m available deck width: 4.0 m free height above the flood flow: 0.70 m installations on the bridge: electrical installations for bridge illumination – material of the deck: reinforced concrete, prestressed
2
Content of the presentation
Task General data of the bridge Description of bridge structures – superstructure:
girder pylon stay cables
– substructure
Analysis of bridge structures – static analysis – dynamic analysis
Some details – reinforcement plans – assemblage of main girder 3
General data of the bridge
According to the given conditions and the accepted concept of precast superstructures the bridge is designed as a cable-stayed beam, with two spans 14.0+56.0=70.0 m The superstructure of the bridge consist of: prestressed concrete deck with 3+2x3 stay cables and one pylon placed on the left river flood plan. Finished road level is set low in the bridge zone; to respect the conditions of free opening above the flood flow, the designed solution has small constant height of the deck: 77.0 cm between the finished road level to the bottom surface of the structure. The bridge is of constant height along the whole span
Desna obala 197.450
Leva obala
196.300 195.60
195.600
193.200
193.125
193.125
M .V. 190.525 190.025
4
General data of the bridge view of the bridge: upstream side
Desna obala 197.450
Leva obala
196.300 195.60
195.600
193.200
193.125
193.125
M .V. 190.525 190.025
Beside the functionality, strict vibration’s and stability conditions, the aesthetic appeal of the bridge was important design constraint. Finished road level is straight and inclined longitudinally towards the left river bank (i=1.37%) 5
General data of the bridge plan of the bridge
TOK 197.45
420
9 197.31 10 10
2%
2%
25
9 197.35
330 1400
25
25
25
6 197.11
8 196.86
520
420
1400
1400 25
1.375 %
25
6 196.39
350
196.30
175
175
7660 1400
350
1400 330
The center line of the bridge is straight, while the center line of the river flow in the bridge zone has curvature of 400.0 m in radius, and intersects the center line of the bridge almost perpendicularly. The deck width is 4.2 m, with both side lateral inclination of 2.0 % from the center line Free profile is 2x2.0/2.5 m along the whole span - passing beside the pylon or stay cables.
6
Description of bridge structures superstructure: girder
Spanning structure: – – –
prestressed concrete girder (C 45), boxed cross section. formed of precaste segments, 14.0 m of length. the height of the girder is constant along the span, with 73.0 cm in the center line, and 68.5 cm form the bottom edge of corona to the bottom surface of girder (intrados) 215.119
D esna obala L eva obala 195.600 195.626
193.125
193.125 192.525
Nasuto tlo
195.60
V. V .195.00
195.619
193.200
196.589
196.549
196.346
196.098
195.819
195.000
197.359
197.319
197.116
196.868
196.589
196.396
192.525
193.200 192.313
192.219
190.500
NPV
Nasuto tlo
M .V .190.525
190.419
190.025
Peskoviti {ljunak 186.700
2 x HW O120 /
2 x HW O100 /
Laporovita glina
l= 22.0 m
l= 10.0 m
Zaglinjeni pesak
330
1400
1400
1400
1400
1400
330
7000
7
Description of bridge structures superstructure: girder
beton in situ 420
montazni nosac N1 985
b. in situ 130
montazni nosac N2 1225
b. in situ 80
montazni nosac N3 1320
montazni nosac N4 1320
b. in situ 80
b. in situ 80
montazni nosac N5 1485
nepokretna lezista pokretna lezista
200 460
25
200
40
16
16
16
25
16
16
292
600 260 260 60 115 115 60
16
25
40
pokretna lezista
100 100 75 75 230 70 70
350
350
350 1400
350
5565 6555 120 120
230 10 8030120 120 120
230 350
350
350 1400
350
230 10 8030120 120 120
230 350
350
350 1400 7000
350
230 10 8030 150 120
230 350
350
350 1400
350
200 350
350
350
350
1400
70 70
– The part of the girder at the left pier, 0.7+3.5 m long, is cast-insitu solid deck. – The cross section of the girder is of shape of trapezium, consisting of two chambers, bordered by the upper deck, two side ribs and one middle rib (in the center line of the bridge). 8
Description of bridge structures superstructure: girder
Cross sections of the girder :
section in the span
2%
2%
Section in the support zone
2%
Section in the pylon zone
2%
2%
2%
9
Description of structures superstructure: girder
215.119
Desna obala Leva obala
196.396
195.600 195.626
196.098
195.819
195.000
195.619
193.200
197.116
196.868
196.589
196.346
197.359
197.319
196.589
196.549
193.125
193.125 192.525
Nasuto tlo
195.60
V. V.195.00
192.525
193.200 192.313
192.219
190.500
NPV
190.419
Nasuto tlo
M .V .190.525 190.025
Peskoviti {ljunak 186.700
2 x H W O120 /
Laporovita glina
l= 22 0 m
l= 10 0 m
Transversal girders:
2 x H W O100 /
main stiffener plates in the load bearing zones are 240 cm width. secondary stiffeners, in the main span, are 16 cm width
Bearing pads:
Fixed end bearings are placed on the left shore pier, designed as prestressed linear hinges (pin joints) Free end bearings (in direction of bridge’s center line) are placed – on the foundation pier of the pylon - elastomer, type NALb 200/250/41 10 – on the right shore pier - elastomer, type NALb 200/250/107
Description of bridge structures superstructure: girder prestressing
After assemblage of the parts of main girder, the girder is made longitudinally continual by means of longitudinal prestressing of cables:
2%
2%
2%
2%
2%
2%
2%
2%
2%
2%
11
Description of bridge structures superstructure: girder prestressing
Cross section of the main girder in IV i V field 2%
2%
2%
2%
12
Description of bridge structures superstructure: girder prestressing
Anchorage zone at left shore pier
2%
2%
2%
2%
Anchorage zone at right shore pier 2%
2%
13
Description of bridge structures superstructure: pylon
215.119
Desna obala Leva obala 195.600 195.626
196.589
196.549
196.346
196.098
195.819
195.000
193.125
193.125 192.525
Nasuto tlo
195.60
V. V .195.00
195.619
193.200
197.359
197.319
197.116
196.868
196.589
196.396
192.525
193.200 192.313
192.219
190.500
NPV
Nasuto tlo
M .V .190.525
190.419
190.025
Peskoviti {ljunak 186.700
2 x H W O120 /
2 x HW O100 /
L aporovita glina
l= 22.0 m
l= 10.0 m
Z aglinjeni pesak
330
1400
1400
1400
1400
1400
330
7000
Central concrete pier, (concrete grade 30), is placed 14 m on the left from the left abutment The pylon height (measured from footing to the top) is 19.5 m The pylon relies on the foundation pier, dimensions b/d/h = 140/ 400 /340 cm which relies on pile helmet (cushion head); piles are φ1200 mm in diameter, l=22.0 m 14 (2HW drilled-in piles)
Description of bridge structures superstructure: pylon
600 150 1950 1200
560 220
60 60
220
196.589
195.819
20 77
195.619
70
130
130
M B 30
100
200
70
200
100
520
340
192.525 192.219 180
First 1.5 m of pylon height the cross section of square shape, solid concrete, following 10.5 m the cross section is voided and mould, 120 x 120 cm, next 1.5 m – the transition to the pylon head (solid mould cross section) head of pylon - solid mould cross section 160.0 x 160.0 cm
80
M B 30
80
215.119
M B 30 190.419 15
60 60
165
165
60 60
15
600
15
Description of bridge structures superstructure: stay cables
Desna obala 197.450
Leva obala
196.300 195.60
195.600
193.200
193.125
193.125
M .V. 190.525 190.025
Three pairs of cables are placed between the left shore pier and the pylon, and they are bonded to the girder in the zone of bearing Between the pylon and the right shore pier three cables are placed, in the center line of the bridge. They are bonded to the girder at the main cross girders
Stay cables are designed for the Freyssinet prestressing system
16
Description of bridge structures superstructure: stay cables, type Freyssinet
17
Description of bridge structures superstructure: stay cables
Anchorage types :
DETALJ ANKEROVANJA KA BLOVA TI PA 12 H TI P PODESAVA JU CI H KOTVI 12 HDE 15 R
– the cables are anchored in the girder at the zone of main transversal girders, transferring force by adjustable anchorage – anchorages at the pylon are fixed.
' 2
' 3
' = 50.485 1
' 1
K 3'
3 = 51.463
15 0
'
20
' 2 = 51.017
K 2'
12 .5
K 1'
22
70
30
20 20
40
70
50
30
30
30
5
40
20
10
40
M ETA LNA M A SKA 5
65
35
70
65
35
100
65 100
α3 =21.812
α3 =51.463
DETA LJ A NKEROV A NJA KA BLA K1 TI P KA BLA 19 H TI P PODESA V A JUCE KOTVE 19 HDE 15 R
1
α2 =28.969
20
14 α2 =51.017
0 17
1 = 45.392
.5 24 α1 =45.392 α1 =50.485
5
16 38 19 4 41.5 31.5 73
35 50 24
M ETA LNA M A SKA 10
80 120
30 5
80 120
18
Description of bridge structures superstructure: stay cables
Details of adjustable anchorage
DETA LJ ANKEROV ANJA KA BLA K2 TI P KABLA 19 H TI P PODESA VA JU CE KOTVE 19 HDE 15 R
DETA LJ A NKEROV A NJA KA BLA K3 TI P KA BLA 19 H TI P PODESA VA JU CE KOTVE 19 HDE 15 R
2
3
20 14
20 14
3 = 21.812
170
80 120
30
15
115 120
50 24
24
10
5
10
50
35
16 38 19 4 41.5 31.5 73
5 35
16 38 19 4 41.5 31.5 73
24. 5
170 24.5
2 = 28.969
10
80 120
30
25
145 130
19
Description of bridge structures superstructure: stay cables design
The criteria considered for structural design of stay cables: ULS: load bearing capacity (maximal tensile force) SLS: deformation of spanning structure SLS and ULS: deformation and stability of pylon building and assemblage ability of structural segments possibility of replacing one cable the verification of the fatigue strength is not necessary done for pedestrian bridges, according to EUROCODE-2, appendix 107-cablestayed bridges Ultimate limit state is defined following EUROCODE-2, with safety factor γs=1.50 for nominal tensioning stress for prestressing steel Serviceability limit state is defined following EUROCODE-2, for frequent constellations of loads, so that the tensile stress in cables does not overcome 0.45 fpk
20
Description of bridge structures superstructure: stay cables design
Prestressing forces inserted into structure by the stay cables, are designed according to the following constraints : the pylon is kept vertical under action of dead load admissible stress and strain range in structural elements (mainly for main spanning structure mostly)
The prestressing of stay cables is performed following the specific prestressing program
21
Description of bridge structures substructure
Substructure of the bridge consists of two shore piers (abutments), and the foundation of the pylon.
88
196.396
F
A
195.600
320
320
195.000 NV V
290
195.626
430
M B 30
192.700
50 50
50 50
193.200
100
450
F
186.700
100
600
450
190.500 NPV
M B 15
280
Presek A -A
700 100
185
320
50 400
A 330
50
185
400
Presek F-F PLA N OPLA TE Levog obalnog stuba
22
Description of bridge structures substructure B 25
420
50 70 5
25
380 155
100
30 20
196.389
25
C D
20
80
20
160
89
50 10
193.200 192.313
195.60
55
211
408
430
20 20 136
370
300
20 30
108 20 77
68 25
197.359
360 280
100 230 100 50 165 165 50 430
HW [ ip O100 / l= 10.0m
A
100
Presek A -A 380 50 75
430
155
100
30
430
430 30 70
230
470
370 25 25
Presek C-C
200
430
200
100 2060 80 20 100
25 25
370
Pogled B-B
70 30
PLA N OPLA TE DESNOG 380 280
OBA LNOG STUBA
20 80
380
30
Presek D-D 430
23
Analysis of bridge structures static analysis
Three calculation models have been created to serve static analysis of the bridge, with element properties according to the building phase
calculation model 1 - space frame, (with decomposition of the main girder in three girders)
24
Analysis of bridge structures static analysis
calculation model 2 - space frame, with
composed main girder
calculation model 3 - plane frame model 3 is used for calculation according to the Second odred theory 25
Analysis of bridge structures static analysis
calculation model 1
- geometry of the system
26
Analysis of bridge structures static analysis
Calculation model 1 - deformation of the system in the phase of assembling (F02), before longitudinal continuity is done
27
Analysis of bridge structures static analysis
Calculation model 1 - deformation of the
formed system under dead load action, in time t=t0
28
Analysis of bridge structures static analysis
Calculation model 1 - deformation of the
formed system under dead load and service load, in time t=t0
29
Analysis of bridge structures dynamic analysis
Three calculation models have been designed to serve dynamic analysis. Continual masses have been represented by system of discrete masses:
calculation model D1 - space frame, with 11 + 6 oscillating masses
30
Analysis of bridge structures dynamic analysis
calculation model D2 - space frame, composed
main girder with 11 + 6 oscillating masses
calculation model D3 - plane frame, 11 + 6
vibrating masses
31
Analysis of bridge structures dynamic analysis
calculation model D3: modes of vibrations of the structure, vertical direction Natural frequency of principal mode f=1.026 Hz (Q=G) f=0.868 Hz (Q=G+p)
III vibration mode
I vibration mode
IV vibration mode
II vibration mode
32
Some details...
• reinforcement plans • assemblage of structures
33
Reinforcement plans
Reinforcement of the pylon
6Rφ25 9Rφ25 Rφ16
3 URφ10/15
1 URφ10/30 2 URφ10/30
34
Reinforcement plans
Reinforcement of the main girder
35
Reinforcement plans
Reinforcement of the main girder
36
Assembling of main girder [ EM A TSKI PRIKA Z JA RM A
Hidrauli~ka presa
Radna platforma
Cev O193 /
2900 h= promenljivo (5900)
For the accepted concept of precast building, during the phase of assemblage the girder relies on the temporary bearings - yokes
1500
h= promenljivo (1500)
Popre~ni presek
190.025
Cev O400 / Dubina zabijanja {ipa min. 5.0m 2500
37
Assembling of main girder
[ EM A TSKI PRI KA Z JARM A Faza utezanja poduznih kablova i Faza utezanja kosih kablova-zatega Podu` ni presek
[ EM A TSKI PRIKA Z JARM A Faza betoniranja spoja montaznih nosaca
h= promenljivo (1500) Cev O193 /
1500
Cev O193 /
Radna platforma
2900 h= promenljivo (5900)
Radna platforma
H idrauli~ka presa
1500
H idrauli~ka presa
2900 h= promenljivo (5900)
h= promenljivo (1500)
Podu` ni presek
190.025
190.025
Cev O400 / Dubina zabijanja {ipa min. 5.0m 2000
Cev O400 / Dubina zabijanja {ipa min. 5.0m 2000
38
Pedestrian bridge over the river Nišava in Niš
Desna obala 197.450
196.300 195.60
195.600
193.200
193.125
193.125
M .V. 190.525 190.025
TOK 197.45
420
9 197.31 10 10
2%
2%
25
197.359
330 1400
25
25
25
6 197.11
196.868
520
420
1400
1400
25
1.375 %
6 196.39
25
Leva obala
350
196.30
175
175
7660 1400
350
1400 330
39
View more...
Comments
