Pretread.com, a reliable source for bridge bearing, neoprene bridge bearing , elastomeric bearings,  ptfe teflon sliding bearings, steel pot bearing, mechanical steel bridge bearings  sliding bearing ptfe Teflon  pipe supports, rubber modular elastomer expansion joint, rubber gaskets is established from 1999 in United Arab Emirates Dubai UAE with ISO certification for design and manufacturing offer products commonly known as bridge bearing, neoprene bridge bearings rubber bearing, steel mechanical bearing, pot bearing, guided mechanical bearing in neoprene, for  bridge building bearing applications replacement  manufacturer manufacturers design designing types supplier installation  

Mob: +971506268246 Mob: +971554784948 Mob: +971543224686 Mob: +971504670267

polymet@pretread.com arulsabu@pretread.com arjun@pretread.com pretread@eim.ae

Bearings Design & Load calculations

Home Services Bearings Design & Load calculations

Bearings Design & Load calculations

Bridge Bearing design calculation Bridge bearing design calculation starts with a bearing schedule and bridge designer is responsible to prepare bearing schedule, which should contain vital information like detailed list of forces, movements and performan

Bridge bearing design starts with a bearing schedule and bridge designer is responsible to prepare one, which should contain vital information like detailed list of forces, movements and performance characteristics which is directly from design of bridge or structure.

Bridge bearing designs have followed one or combinations of following specifications.

AASHTO LRFD Bridge Design Specifications, Customary U.S. Units, 7th Edition, with 2015 Interim Revisions. AASHTO LRFD Bridge Design Specifications are intended for use in design, evaluation, and rehabilitation of bridges, and are mandated by the Federal Highway Administration for use on all bridges using federal funding. These Specifications employ the Load and Resistance Factor Design (LRFD) methodology using factors developing from current statistical knowledge of loads and structural performance.

 AASHTO M215-2006

AASHTO M 251-2006 standard specification for plain and laminated elastomeric bridge bearings This specification covers material requirements for plain and laminated elastomeric bridge bearings. Elastomeric bearings furnished under this specification shall adequately provide for thermal expansion and contraction, rotation, lateral and transverse movements of bridge structure.

BS 5400 – British  Standards.

 BS 5400 is British Standard code of practice for design and construction of steel, concrete and composite bridges, which is applicable to highway, railway and pedestrian bridges. BS 5400  standard  includes  specification and calculation of standard bridge loads,  application of  limit state principles,[4] analysis, and fatigue load calculation[5] and  reservoir method for fatigue load cycle counting.[5]. BS 5400 standard also specifies  requirements and code of practice[1][2] on design of steel,[1] concrete (reinforced, prestressed or composite)[2] and composite bridges that use steel sections (rolled or fabricated, cased or uncased)[3] as well as  materials and workmanship in bridge erection.Some part of standard is partially replaced by BS EN 1337-2 (EN 1337-2), BS EN 1337-3 (EN 1337-3), BS EN 1337-5 (EN 1337-5) and BS EN 1337-7 (EN 1337-7), and replaced by BS EN 1337-4 (EN 1337-4) and BS EN 1337-6 (EN 1337-6) but remains current)

 BS EN 1337-3:2005

 After formation of European Union in 1999 BS 5400 has been amalgamated into BS EN 1337-5:2005 which specifies requirements for  design and manufacture of elastomeric bridge bearings, pot bearings and ptfe Teflon sliding bearings. 

 Australian Standard ™ Bridge design Part 4: Bearings and deck joints -AS 5100.4—2004  AP-G15.4/04.

This Standard was prepared by the Standards Australia Committee BD-090, Bridge Design to supersede HB 77.4—1996,  Australian Bridge Design Code Section 4: Bearings and deck joints and AS 1523, Elastomeric bearings for use in structures. The AS 5100 series represents a revision of the 1996 HB 77 series, Australian Bridge  Design Cod, which contained a separate Railway Supplement to Sections 1 to 5, together with Section 6, Steel and composite construction, and Section 7. AS 5100 takes the requirements of the Railway Supplement and incorporates them into Parts 1 to 5 of the present series, to form integrated documents covering requirements for both road and rail bridges. In addition, technical material has been updated. This Standard is also designated as AUSTROADS publication AP-G15.4/04.

Above standards are available to purchase from internet through authorized sellers as they all come under copy compliance- copyright requirements and please follow basic guidelines in copying them:

Bridge bearing design calculation starts with a bearing schedule and bridge designer is responsible to prepare bearing schedule, which should contain vital information like detailed list of forces, movements and performance characteristics which is directly from design of bridge or structure.

On receipt of above inputs in a formal Bearing schedule ( which can be downloaded from downloads, ) bearing designer -normally manufacturer side -  use  information received  to determine  design values with full specification. Most useful and informative  schedule  template  given for bearing design, is  in Table B.1 Annex B of BS EN 1337-1[1] or can find similar schedule in AASHTO LRFD.
 
 
For bridge bearing design calculations, required design criteria includes:
 
Longitudinal and transverse movement
Longitudinal, transverse, and vertical rotation
Longitudinal, transverse, and vertical loads
Shear modules used in structure design
Maximum vertical deflection – based on structure design
Longitudinal and transverse  shear stiffness 
 
To meet AASHTO or BS EN requirements following design steps - checks - are to be followed meticulously and a well-defined design calculation sheet will be submitted to bridge designer for approval of bearing type and size.
 
1 - Obtain Design Criteria
2 - Optimum Bearing Type
3 - Preliminary Bearing Properties.
4 - Design Method A or B as per AASHTO LRFD
5 - Compute Shape Factor - 
6 - Compressive Stress - 
7 - Compressive Deflection - 
8 - Shear Deformation - 
9 - Rotation or Combined Compression and Rotation
10 - Stability
11 - Reinforcement
12 - Design for Anchorage
13 - Design Anchorage for Fixed Bearing
14 - Draw Schematic of Final Bearing Design
 
Above bridge bearing design calculations steps clearly shows that bridge bearings sourced from any bridge bearing manufacture offering bearing sizes without design sheet will only end up Project in disaster. Indicative dimensions of bearings provided in our catalogue are only indicative and only for reference. 
 
Sourcing bearing size and structure designed by pretread.com- and later our  design calculation sheets of  pretread.com passed over to alternative manufacture has reported to end up in grave disaster, as our designs are based on many years of experience in design  manufacturing prototyping and  testing,  superior quality of rubber neoprene compound and rigorous  post production testing and bridge inspection followed. Contact us to design correct bearing for your Projects with bearing schedule.
 
Thank you