This document discusses bridge bearing pads and expansion joints. It provides details on: 1. The types of bridge bearings including elastomeric bearings, steel bearings, and pot bearings. It describes the purpose, design considerations, and testing methods for bearings. 2. A worked example showing how to design an elastomeric bearing pad. 3. The sources and calculation of movements in bridges that bearings and expansion joints must accommodate. 4. The types and design of expansion joints used in bridges including considerations for the range of movement, loads, and compatibility with bearings.

1. Bridge Bearing Pads Expansion Joints Dowel Bars Bridge Parapets Bridge Drainage System Fascia Contact us: Plot # 377, Nawab Siddiq Ali Khan Road, Lasbella, Garden West, Karachi-74550, Sindh-Pakistan Landline: 00.92.21.3223.2834 Fax: 00.92.21.3225.9779 Cell: +92.321.821.8443 Web: www.azizahmad.com - www.rainbowenterprise.org

3. BRIDGE BEARINGS

8. Details of Elastomeric Bearing Pad: Bridge spanning The plan size of bearing is normally governed by the width of the beam it supports and the width of the abutment seating in the direction of span. Outer Steel Plate Inner steel plate Inner Elastomer slab Outer Elastomer Slab Shape Factor: B = effective width of bearing L = effective length of bearing A = effective plan area of elastomer (BxL) Ao = actual plan area of elastomer T = total thickness of bearing t = actual thickness of an elastomer Σ t = total thickness of elastomer slabs tn = effective thickness of an elastomer slab in compression (tn = t for an inner slab, tn=1.4t for outer slab, tn=1.6t for pad or strip bearing) T B L

9. S = (BxL) 2(B + L) tn Behaviour of Elastomeric Bearing Pads: The Shape Factor: S = shape factor = ratio of effective plan area to force-free surface area of an elastomer.

11. Properties of Elastomer Values from AASHTO M251 ASTM D4014-03: Limiting Values ASTM (D4014-03 (2007) D2240

17. Rubber Pot Bearing Pads AASHTO M251: These bearings incorporate a disc of rubber trapped inside a shallow piston and cylinder assembly. The result is similar to a hydraulic cylinder containing a viscous fluid, and the rubber disc can support pressures. The piston can tilt within the cylinder without damage to itself or the rubber and rotation capacities can be achieved. Horizontal translation can be achieved by using a sliding bearing on one external face. Standard bearings are manufactured which offer a range of vertical load capacities of up to 30,000kN and cater for horizontal movements of more than 50mm.

19. Worked Example on Bearing:

20. Worked Example on Bearing:

21. Worked Example on Bearing:

22. TEST METHOD OF BRIDGE BEARING: Hardness: ASTM D 2240 Tensile: ASTM D 412 Elongation: ASTM D 412 Heat Resistance: ASTM D 573 Compression Set ASTM D 395 Ozone ASTM D 1149 Low Temperature Brittleness ASTM D 746 Instantaneous Thermal Stiffening ASTM D 1043 STANDARDS: ASTM D 4014-03: Specification for Plain and Steel-Laminated Elastomeric Bearings for Bridges ASTM D 5977-03: Specification for High Load Rotational Spherical Bearings for Bridges and Structures. AASHTO M 251-06 UL: Plain and Laminated Elastomeric Bridge Bearings.

23. EXPANSION JOINTS

26. Choice of Bridge Joints: Where the deck and substructure have been designed to incorporate deck joints then the following guidance is given in M 213 for the range of movements that can be accommodated by the various joint types: 3 * 25 7. Cantilever comb or tooth joint. 3 * 5 6. Elastomeric in metal runners. 3 * 5 5. Reinforced Elastomeric. 3 40 5 4. Nosing with preformed compression seal. 3 12 5 3. Nosing joint with poured sealant. 3 40 5 2. Asphaltic Plug joint. 1.3 20 5 1. Buried joint under continuous surfacing. Maximum (mm) Minimum (mm) Maximum Acceptable Vertical Mvement Between Two Sides of Joint (mm) Total Acceptable Longitudinal Movement JOINT TYPE

27. Types of Joints: This type gives a very comfortable riding surface, but the capacity of movement is restricted to 30mm. Only light or semi dense traffic can be carried. An elastomeric profile with steel plate inserts is fastened on two steel plates and anchored in the slab. Movements of up to 300mm are possible.

28. Types of Joints: Two thick and firmly anchored sheets slide one into the other. They are in the form of straight or biased teeth which allow movements of 25 to 350mm. Larger joints require intermediate support of the teeth.

30. DOWEL BARS

31. Dowel Bars AASHTO M 31 : Fixed end supports in bridges are provided for by dowel bars. At the free end, the support members can rotate and move horizontal whereas at the fixed end only rotation is allowed while all horizontal movements are restrained. The dowel bars pass from the beams to the abutment and are normally placed between bearings to facilitate easy replacement of bearings. Sometimes where space is restricted, elastomeric bearings are provided with holes for dowel bars to pass through. Design Criteria for Dowel Bars: Longitudinal movements of the deck will be accommodated by the bearings at the free ends and horizontal loads will be carried by the dowel bars at the fixed ends. The dowel bars shall be designed to resist a combination of horizontal loads due to tractive load (Tr), wind load (W) and loads due to shrinkage, temperature and creep (FSTC). The dowel bars are specified by suitable diameter and minimum embedded length ( usually made to reach the main reinforcement in the support).

32. é é é w w Dowel Bar (Plan View) 45 o 45 o Dowel Bars AASHTO M 31: Embedded length = l beam For Inverted T-beams, é = ½ (Total length of beam – effective length) For I-beams, é= ½ (thickness of end diaphragms)

34. BRIDGE PARAPETS

37. Rainbow Bridge Parapets: New Jersey Parapet with galvanized iron railing Standard kerb with railing The Design Manual for Roads and Bridges AASHTO M111 & M232 Specifies a Group Designation for various containment levels.

39. BRIDGE DRAINAGE SYSTEM

41. Drainage System:

43. FASCIA

45. Plot: 377, Street: Nawab Siddiq Ali Khan Road, Area: Lasbella, Garden West, City: Karachi. Postal Code: 74550 Province: Sindh Country: Pakistan Landline: 00.92.21.3223.2834 Fax: 00.92.21.32259779 Website: www.azizahmad.com - www.rainbowenterprise.org Email: [email_address] - [email_address] Contact us:

46. C a l e n d a r 2010 Contact us: Plot # 377, Nawab Siddiq Ali Khan Road, Lasbella, Garden West, Karachi-74550, Sindh-Pakistan. Landline: 00.92.21.3223.2834 Fax: 00.92.21.3225.9779 Cell: +92.321.821.8443 email: [email_address] - [email_address]