Ⅰ. CKPZ Series Bridge pot bearing's specification.
1. |
① bridge (2007) 8360-CKPZ series of simple supported girder bridge bearings have 12 grades in terms of capacity of reaction force (vertical load): 1000, 1500, 2000, 2500, 3000, 4000, 5000, 5500, 6000 and 7000KN; |
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② bridge (2007) 8360-CKPZ series of multi-span continuous girder bridge bearings have 35 grades in terms of capacity of reaction force (vertical load): 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 22000, 24000, 26000, 28000, 30000, 35000, 40000, 45000, 50000 and 60000 KN; |
2. |
Design turning angle: 0.02rad |
3. |
Horizontal load of bridge bearings |
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(DX) Multi-way movable bearings withstands 3% of the design reaction force Under vertical load, horizontal design force of every direction of fixed bearing, vertical movable bearing in cross-bridge direction and horizontal movable bearing in bridge axial direction: |
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① bridge (2007) 8360-CKPZ series of simple beam bridge bearings:
15%---- region's ground motion peak acceleration Ag ≤ 0.1g
30%----region's ground motion peak acceleration 0.15 < Ag ≤ 0.2g |
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② bridge (2007) 8360-CKPZ series of multi-span continuous beam bridge bearings:
15%---- region's ground motion peak acceleration Ag ≤ 0.1g
22.5%----region's ground motion peak acceleration 0.1 < Ag ≤ 0.15g |
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Notes: when the region's ground motion peak acceleration is faster, the bridge bearing can be made specially. |
4. |
Design displacement of bearings |
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① bridge (2007) 8360-CKPZ series of simple beam bridge bearings: Multi-way movable bearings and vertical movable bearing in bridge axial direction :
1000~3000 ± 50mm
3500~7000 ± 60mm
Multi-way movable bearings and horizontal movable bearing in cross- bridge direction :
± 10mm |
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② bridge (2007) 8360-CKPZ series of multi-spam continuous beam bridge bearings:
Multi-way movable bearings and vertical movable bearing in bridge axial direction :
3000~10000 ± 100mm
3000~10000 ± 150mm
Multi-way movable bearings and horizontal movable bearing in cross- bridge direction :
± 25mm |
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Notes: when the required movement factor is different from the factor mentioned above, the bridge bearing can be made specially |
5. |
Movable bearing's design friction coefficient: |
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Normal temperature : 0.03
Cold resistant: 0.05 |
6. |
CKPZ series of bearings with mechanical adjusting height: 0 ~ 20mm |
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Notes: when the required capacity of adjusting height is bigger, the bridge bearing can be made specially. |
7. |
Temperature scope of application |
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Normal temperature (natural rubber): -25 ~ + 60 ℃
Cold resistant (natural rubber or ethylene propylene diene monomer ): -40 ~ + 60 ℃ |
8. |
Scope of track gradient : 0 ~ 20 ‰ |
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① bridge (2007) 8360-CKPZ series of simple beam bridge bearings adopt changing the top surface of top anchor plate to fit the requirement of gradient:
0≤ i ≤4 ‰, no gradient.
4 ‰ < i ≤12 ‰ gradient: 8 ‰
12 ‰ < i ≤20 ‰ gradient: 16 ‰ |
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② bridge (2007) 8360-CKPZ series of cast in place simple beam bridge bearings and multi-spam continuous beam bridge bearings: no gradient on the top surface of top anchor plate, adopt adjusting the concrete of mudsill. |
Ⅱ. CKPZ Series Bridge pot bearing's design allowable stress of main material.
Confined rubber plate: 25MPa
CKPZ Series bearings adopt UHMW-PE (Ultra-high molecular weight polytetrafluoroethylene ). Average allowable stress: 45MPa
Steel parts adopt Q345 low-alloy high strength constructional steel or forgings, which reaches the standard of GB/T1591.
SF-1 three-ply cladding sheet: 65MPa
40 Cr anchor bolt allowable shearing stress: 280MPa
Ⅲ. CKPZ Series Bridge pot bearing's requirements of materials
1. Metal material (attach material specification)
Plain carbon structural steel meets the requirement of GB700; 35# or 45# high quality carbon structural steel meets the requirement of GB/T699; 40Cr steel's performance satisfies the requirement of 《 Alloy Structural Steel -GB/T3077 》 .
Main steel parts adopt Q345 low-alloy high strength constructional steel or forgings, which reaches the standard of GB/T1591. Processed forgings are carrying with ultrasonic inspection .
Stainless steel of bearings adopts 0Cr17Ni12Mo2 or 00Cr17Ni14Mo2, which meets the requirement of cold rolled stainless steel plates -GB3280; Surface roughness Ra ≤ 0.1 μm.
Inner ring adopts Hpb59-1, lead brass, its chemical constituents satisfy the standard of GB/T5231-2001.
2. Nonmetallic material
Physical and Mechanical properties of Elastomeric Bearings:
Item |
Natural Rubber |
Test Measure |
Hardness (IRHD) |
55±5 |
GB/T6031 |
Tensile strength (MPa) |
≥17.5 |
GB/T528 |
Elongation at break (%) |
≥400 |
GB/T528 |
Brittleness temperature ( ℃ ) |
≤-55 |
GB/T1682 |
Permanente deformation by Constant compression ( 70 ℃ *22h)% |
≤30 |
GB/T7759 |
Ozone aging ( 40 ℃ *96h, 25pphm, 30% elongation ) |
Crack-free |
GB/T7762 |
Hot air aging experiment |
Experimental condition ( ℃ *h) |
70*168 |
GB/T3512 |
Tensile strength reduction rate (%) |
≤15 |
Elongation at break (%) |
≤20 |
Hardness change (IRHD) |
±10 |
bearings adopt UHMW-PE (Ultra-high molecular weight polytetrafluoroethylene ) to frictionates with stainless steel plate
The minimum thickness of UHMPE plate is 7 mm , the deviation of exerted thickness meets the requirement of No. 4.4.2 in TB/T2331-2004.
Sliding surface of UHMW-PE plate has lipid groove to store silicone grease 5201-2. The plane dimension and arrangement of lipid groove meet the requirement of No. 4.4.2 in TB/T2331-2004.
Physical and Mechanical properties of UHMW-PE plate
Item |
Test measure |
Specification |
Density |
GB/T 1033 |
0.93~ 0.98 g /cm3 |
Elastic modulus |
GB/T 1040 |
850MPa (±20%) |
Tensile strength |
IS0527-1, IS0527-3 five types of samples, thickness- 2± 0.2mm , smooth surface, drawing speed 50mm /min |
≥ 30MPa |
Elongation at break |
GB/T 1040 |
≥250% |
Ball indentation hardness H132/60 (load 132N, sustained load 60s) |
GB/T 3398 |
33±20% MPa |
① Barings adopt UHMW-PE plate to frictionate with stainless steel plate within 5201 silicone grease lubrication:
Normal temperature: 21 ℃ ± 1 ℃
Compressive stress: 45MPa
Initial static friction coefficient : ≤ 0.008
Line attrition loss: ≤ 5μm/km
② Except the regular test of UHMW-PE plate, one of final products (less than 100) will be chosen to make standard samples to do density, ball indentation hardness , elongation at break and tensile strength test. The result needs to meet the standard requirement.
③ Polytetrafluoroethylene plate sticks with substrate steel plate, adhesive is insoluble and thermosetting, as well as, peeling strength is more than 5N/mm.
SF-1 three-ply cladding sheet is made from bronze, bronze powder and UHMW-PE by sintering. The thickness of substrate bronze plate is 2.0± 1.15mm ; the thickness of interlayer sintered from bronze powder is 0.25± 8.5mm ; surface is sintered from 20% plumbum and 80% Polytetrafluoroethylene , its thickness is 0.01± 8.02mm ; the thickness of composite plate is 2.4± 8.1mm .
SF-1 three-ply cladding sheet needs to be folded repeatedly. Folding angle is ±60°, there is no delamination . Physical and mechanical properties of SF-1 meet the requirement of TB/T2331.
Physical and mechanical properties of 5021 superior silicone grease lubrication meet the requirement of HG/T2505.
Ⅳ . Bearing making and quality control
1. After bearing making, dimensional precision and surface roughness is accordant with the design drawing:
Surface roughness between bearing pad and plug: Ra ≤ 1.6 μm.
Surface roughness between bearing pad, plug and rubber block:
Ra ≤ 3.2 μm.
Notes: dimension error of no-described parts is accordant with the grade M of GB/T1804-2000.
2. After ball throwing, bearing steel parts need to be processed in anticorrosion and coating within 2 hours.
3. Welding ring of bearing pad and linked caking should satisfy the followings:
Ring of bearing pad has the same materials as linked caking, bilateral inverted grooves and bearing pad need to be welded eventually, as well as, there are not crack, slag inclusion, stomata. Linked caking should carry with ultrasonic inspection , the quality meets the Grade I of GB50221.
4.Stainless steel cold rolling plate and substrate sheet adopt argon arc welding. Flatness of stainless steel is accordant with design drawing.
5.Anticorrosion and dustproof of bearings meet the requirements of 《 provisional specification of passenger dedicated bridge pot bearing 》 and design drawing.
Ⅴ . Assembly of bridge bearing
1. Each part of bearing has kite mark from department of quality determination, purchased parts attach certificate of soundness, as well as, its main specification has rechecked report.
2. Bearing sliding surface (stainless steel surface and PTFE surface) utilizes acetone or alcohol to clean up. Check arrangement of silicone grease groove. Silicone grease fully stores groove of PTFE surface without stomata.
3. Before assembly, clean up bearing pot inner and smear silicone grease. During assembly, using round mallet to hammer lightly attach the two closely without air interlayer.
4. After assembly, the following error satisfies the requirement of design drawing.
① The gap between bearing pad and plug ≤ 0.5mm
② The gap between the guide of single direction active bearing and the groove of sliding surface: 0.3mm ~ 0.7mm
③ Shear pin and sliding surface: H7/P6
④ The gap between shear pin and the top surface of top anchor plate ≤ 0.75mm
5. After assembly, non-parallelism of bearing upper plane and under plane is less than diameter or 2‰ of length edge.
Vertical load < 20000KN, error ≤ ± 2mm
Vertical load ≥ 20000KN, error ≤ ± 3mm
Ⅵ . Quality control of bearing
Quality control of bearing is divided into 3 classes- material inspection, factory inspection and modal examination. The item and period of inspection meet the requirement-No. 5.1, 5.2, 5.3 of 《 provisional specification's supplementary provision of passenger dedicated bridge pot bearing 》 ; The result of inspection meets the requirement-No. 5.3 of 《 provisional specification of passenger dedicated bridge pot bearing 》
Ⅶ . Mark, package, storage, transportation, handover of bearing meet the requirement- No. 6 of 《 provisional specification of passenger dedicated bridge pot bearing 》