- Need to conduct experimental testing off steel cable in accordance with the requirements of design documents for the target: Max tension load, modulus of elasticity, yied strength, elo
Trang 1Order of installation, tension cable girder i24m
I Some provisions of materials and equipment trension cable
I.1 Main section
- Compressive strength of samples prismatich 28 days: f’c=40MPa
I.2 Cable.
- Cable use type strand 7 plys Garde 270 by standard ASTM A416 with specs as follows: + Nominal diameter
+ Nominal area
+ Yied strength
: D = 12.7 mm
: A = 99.5 mm2 : fpy = 1717.07 Mpa
Trang 2+ Tensile strength
+ Max tensile load
+ Modulus of elasticity
: fpy = 1957.7 Mpa
: Ppu = 174.7 KN
: Ep = 1.98x105 Mpa
- Cable
Name Number strand
12.7mm in cable
Anchor Load tension (KN) Nomianal area
(mm2)
- Cables must be preserved in sheltered, dry ventilated area, 30cm stats above the ground
- Cable while being used must have a certificate used by the manufacturer, the Owner and design consultant approved
- Need to conduct experimental testing off steel cable in accordance with the requirements
of design documents for the target: Max tension load, modulus of elasticity, yied strength, elongation, the size of each wire in the strand, surface current Any change that does not comply with the provisions of design documents that must be design agency, investor, concultant supervision accepted in writing may be used
I.3 Anchor
- Use anchor -12 of firm QVM produce cable 12.7mm
- Anchors has to enter on the centificate of quantity manufacturers
I.4 Jack
- Use 2 jacks 250T symbol YCQ 250Q
- Some feature of the jack:
+ Max tension force : 248 TÊn
+ Max tension stroke : 200 mm
+ Tension piston area : 459.20 cm2
+ Revenues piston area : 280.40 cm2
- Pump model ZB4-500
- All jacks, pump before being used must be tested
II Order rension.
II.2 Order.
- Calculation force tension cable
- Calculation elongation
- Execution cable passing
- Tension cable
Trang 3- Finish.
III.Work.
III.1 Calculation tension cable.
The actual force that the tension cable designed as to adjust the jack and gauge
a Actual tension cable regardless of the friction adjust jack
Jack
Pump
Gauge
:YCQ250Q :ZB4-500
Symbol Symbol
:Z06139 7013.119
No Grade of
force
Reaquired tension force
Calculation pressure
Actual tension force
Fiction factor
Jack
Pump
Gauge
:YCQ250Q :ZB4-500
Symbol Symbol
:Z06180 7030.119
No Grade of
force
Reaquired tension force
Calculation pressure
Actual tension force
Fiction factor
b Actual cable tension regardless of meter calibration
Jack
Pump
Gauge
:YCQ250Q :ZB4-500
Symbol
Symbol
:Z06139
7013.119
No Garde of force Reaquired tension
force
Actual tension force
Trang 41 0.10P 159.6 3.85
Jack
Pump
Gauge
:YCQ250Q :ZB4-500
Symbol Symbol
:Z06180 7030.119
No Garde of force Reaquired tension
force
Actual tension force
III.2 Calculation elongation.
a Theory elongation:
Formula:
- L:Elongation of cable (mm)
- Ln: Length of cable (mm)
- Ep: Modunlus elasticity, follow testing : Ep =1.96x105 Mpa
- n, n+1: Stress of cable at point n and point n+1
n = Pn/Ap
n+1 = Pn+1/Ap
- Pn, Pn+1 Force tension cable at point n and point n+1
- Pi: Force tension cable
p
1 n n n
E 2
( l
Δ
l) exp(
(1
P
n
λ α μ γ)
Trang 5- Area cross section of cable: F = 1185(mm2).
- : Fiction between anchor and jack
- : Friction of line cable, (rad-1)
- : Angle of the cable line from the anchor point jack(degrees)
- : The coefficient of friction between the cable to the pipe, = 0.004 rad/m-1
- L=Ln: Length of cable
Calculation length of cable: L(Ln) = 2*(Ltc+L1+L) (with tension)
+ Ltc: Length of cable consstruction in jack =740 (mm)
+ L1: The length from the edge girder to the jack ( head jack)
- + L: Distance cable length in the girder
b Calculation:
- Calculation elongation from grade force 0.1P
+ Elongation of cable form grade 0.1P-1.1 when use type jack YCQ250Q-06139
elongation of cable from grade force
Độ dãn dài theo cấp lực calculating sheet/bảng tính:
elongation of prestressing cable of pci l=24m
độ giãn dài cáp dự ứng lực dầm pci l = 24(m)
No/
Thứ
tự
Grade of
tension
force/Cấp
lực căng kéo
Required tension force/
Lực căng kéo yêu cầu
Actual pressure/ áp suất căng kéo thực tế
Cable No.1 Bó
số 1
Cable No.2 Bó
số 2
Cable No.3 Bó
số 3
1 0.1P 159.6 3.85 hồi kíchSo dây hồi kíchSo dây hồi kíchSo dây
2 0.1P 159.6 3.85 đo dãn dàiĐánh dấu đo dãn dàiĐánh dấu đo dãn dàiĐánh dấu
3 0.2P 319.2 7.33 1.75 1.74 1.61
4 0.4P 638.4 14.33 5.25 5.22 4.82
5 0.6P 957.6 21.32 8.75 8.70 8.03
6 0.8P 1276.8 28.32 12.25 12.17 11.24
7 1.0P 1596.0 35.32 15.76 15.65 14.45
Trang 68 1.05P 1675.8 37.07 16.63 16.52 15.26
9 1.10P 1755.6 38.82 17.51 17.39 16.06
+ Elongation of cable form grade 0.1P-1.1 when use type jack YCQ250Q-06180
elongation of cable from grade force
Độ dãn dài theo cấp lực calculating sheet/bảng tính:
elongation of prestressing cable of pci l=24m
độ giãn dài cáp dự ứng lực dầm pci l = 24(m)
No/
Thứ
tự
Grade of
tension
force/Cấp
lực căng kéo
Required tension force/
Lực căng kéo yêu cầu
Actual pressure/ áp suất căng kéo thực tế
Cable No.1 Bó
số 1
Cable No.2 Bó
số 2
Cable No.3 Bó
số 3
1 0.1P 159.6
3.85
So dây hồi kích
So dây hồi kích
So dây hồi kích
2 0.1P 159.6
3.85
Đánh dấu
đo dãn dài đo dãn dàiĐánh dấu đo dãn dàiĐánh dấu
3 0.2P 319.2
7.33 1.75 1.74 1.61
4 0.4P 638.4
14.33 5.25 5.22 4.82
5 0.6P 957.6
21.32 8.75 8.70 8.03
6 0.8P 1276.8
28.32 12.25 12.17 11.24
7 1.0P 1596.0
35.32 15.76 15.65 14.45
8 1.05P 1675.8
37.07 16.63 16.52 15.26
9 1.10P 1755.6
38.82 17.51 17.39 16.06
c Limit elongation:
Limit elongation was built from the elongation with the theoretical error
(specifications of the project) The value of to determine the upper limit, the theoretical approach
Trang 7IV Order.
- Cable 1
- Cable 2
- Cable 3
When pulling cable 2 bundles, the pressure jack in not a difference of more than one level Before tension to make sure the size axis coincides with the axis of the tendon at the anchor and head size spleen at night
c Order tension and monitor elongation
Installation into a cable tension by following the steps order
Step 1: First.
1 Pump 0,1P0
2 Close the node anchor on the passive ( tubes closed anchor button and hammer )
3 Installation cursor measured in the first two active and passive
Step 2:Pump to 0,2P0 Marked point track elongation
Step 3: Pump to 0,4P0 Measurement of elongation at the initiative, which moved the cursor at the passivity of the tractor, check the results on graph stretched and record monitoring results on the table
Step 4: Pump to 0,6P0 Measurement of elongation at the initiative, which moved the cursor at the passivity of the tractor, check the results on graph stretched and record monitoring results on the table
Step 5: Pump to 0,8 P0 Measurement of elongation at the initiative, which moved the cursor at the passivity of the tractor, check the results on graph stretched and record monitoring results on the table
Step 6: Pump to 1,0 P0 Measurement of elongation at the initiative, which moved the cursor at the passivity of the tractor, check the results on graph stretched and record monitoring results on the table
Elongation is calculated by taking elongation at the top of the active minus the
displacement of the cursor at the lower size chart stretched to 0 and click to remove
The final elongation A0
In the value of elongation in the lower size chart stretched to 0 and click to move
The strand is cut the tail and the sleeves of the nozzles are welded
Elongation of cbale: Elongation of the tendon to re-adjust based on the area and the actual elactic modulus of the strand from the experimental results
Remove jack
Exhaust jack to 0 pull jack
III.5 Grout pump, finish.
a Cut the cable anchorages covering
b Pump groupting protecting cables
+ Mix the grout according to gradation of the experiment
+ Pump grouting