About Bridge pier.

Cheek this for learn about Bridge & bridge pier. It can helpful for know about various types of bridge pier.

1. Welcome To Presentation

2. Course Code: CE414 Course Title: Structural Analysis and Design Sessional II Course Teacher Shabbir Ahmed Osmani Senior Lecturer Department of Civil Engineering, Leading University, Sylhet .

3. Presentation On Bridge Pier

4. Prepared By Tajul Islam ID: 1512060013 Semester: 8 th Batch: 10 th Department of Civil Engineering Leading University, Sylhet .

5. Introduction Piers provide vertical supports for spans at intermediate points and perform two main functions transferring superstructure vertical loads to the foundations and resisting horizontal forces acting on the bridge. Although piers are traditionally designed to resist vertical loads, it is becoming more and more common to design piers to resist high lateral loads caused by seismic events. Even in some low seismic areas, designers are paying more attention to the ductility aspect of the design. Piers are predominantly constructed using reinforced concrete. Steel, to a lesser degree, is also used for piers. Steel tubes filled with concrete (composite) columns have gained more attention recently.

6. What is Bridge? A bridge is a structure that is built over a railway, river, or road so that people or vehicles can cross from one side to the other.

7. Component of Bridge Every bridge can be divided broadly into three parts. 1. Superstructure 2. Substructure 3. Foundation Superstructure Superstructure  that part of the structure which supports traffic and includes deck, slab and girders. All the parts of the bridge which is mounted on a supporting system can be classified as a Super structure. Substructure Substructure that part of the structure, piers and abutments, which supports the superstructure and which transfers the structural load to the foundations.

8. Foundation Foundation is the component which transfers loads from the substructure to the bearing strata. Depending on the geotechnical properties of the bearing strata, shallow or deep foundations are adopted. Usually, piles and well foundations are adopted for bridge foundations. Now let’s know about the five major parts of R.C.C bridge.

9. Beam / Girder Beam or girder is that part of superstructure which is under bending along the span. it is the  load bearing member which supports the deck. Bearing Bearing transfers loads from the girders to the pier caps. Bearing is a component which supports part of the bridge and which transmits forces from that part to another part of the structure whilst permitting angular and/or linear movement between parts. Pier Cap / Headstock Pier Cap / Headstock is the component which transfers loads from the superstructure to the piers. Pier cap provide sufficient seating for the Bridge girders and disperse the loads from the bearings to the Piers.

10. Pier  Pier is that part of a part of the substructure which supports the superstructure at the end of the span and which transfers loads on the superstructure to the foundations. Piers are compression members. Depending on the loading and bearing articulations, piers may be subjected to bending as well. Pile cap and Piles Pile foundation is the most commonly used foundation system for bridges. Pile is a slender compression member driven into or formed in the ground to resist loads. A reinforced concrete mass cast around the head of a group of piles to ensure they act together and distribute the load among them it is known as pile cap.

11. Now let’s discuss about “Bridge Pier”.

12. What is Bridge pier? Bridge Pier support the spans of the bridge and transfer the loads from superstructure to the foundation. Piers should be strong enough to take the vertical load and horizontal forces. Its main function is to transfer the load from the bridge superstructure to foundation. They are subjected to huge axial loads and bi-axial moments and shear forces in transverse and longitudinal direction. Said that, pier are usually compression elements of a bridge.

13. Types of Pier? Type of piers to be used in the bridge depends upon the type of bridge, sub-soil conditions as well as the procedure adopted for the construction of bridge. The bridge pier can be broadly divided into two parts: 1. Solid piers 2. Open piers 1. Solid piers These piers have solid and impermeable structure. The generally used materials used for the construction of these type of piers are bricks, stone Masonry, Concrete or RCC, etc. They may be further classified as: a. Solid masonry pier. b. Solid RCC pier.

14. Solid masonry pier Masonry piers are normally provided in residential buildings to support the ends of beams. Once the length of a wall becomes less than 3 times its thickness it is called a pier (or column) rather than a wall.

15. Solid masonry pier.

16. Solid R.C.C. pier The solid piers which are constructed with the reinforcement are called R.C.C. piers. These piers are generally rectangular in cross-section and are generally used where the height of the piers are more and the solid masonry piers. Solid R.C.C. pier.

17. 2. Open piers The piers which are open also allows the water to pass through the structure are called as open piers. Open piers can be classified into the following types: a. Cylindrical piers b. Column bents c. Trestle piers or Trestle bent d. Pile bents e. Special or typical framed piers

18. Cylindrical piers The piers which are constructed with the mild steels or cast iron cylinder in which the concrete are filled are known as cylindrical piers. These are used for bridges having moderate height. Sometimes horizontal and diagonal steel bracing are also provided for additional stability. Cylindrical piers.

19. Column bents A rigid frame commonly made of reinforced concrete or steel that supports a vertical load and is placed transverse to the length of a structure. Bents are commonly used to support beams and girders. An end bent is the supporting frame forming part of an abutment. The vertical members of a bent are columns or piles. Column bents.

20. Trestle piers or Trestle bent It consist of column with bent cap at the top. As per the latest recommendation the hinges may also be provided. It is generally used for flyovers and elevated roads. These are suitable for bridges where water current is slow and river bed is sufficiently firm. Trestle bent.

21. Pile piers or Pile bents These are used where the ground is unstable and the low piers are required. In these type of piers number of steel or RCC piles are driven into the ground provided with the cap at their top to support the main girder. It is the common variation of multicolumn bent. It is generally used for the type of bent on low height and short span structure. Pile bent.

22. Typical Framed Piers These are the latest type of piers used in the bridges. In these piers the effective span length for girders get reduced. Hence the construction will be economical. Typical Framed Piers.

23. Classification of Bridge Piers based on Force Transfer Mechanisms Based on the type of forces the pier is subjected to bridge piers are classified as: Fixed piers. Free piers. Fixed pier This is actually be R.C.C. pier. When a bridge pier casting with girder or slab simultaneously, this is call fixed pier.

24. Fixed piers.

25. Free pier. Free pier Free pier is one kind of timber pier. When a bridge pier be timber and the slab or girder just stay above in this pier without any fixed joint, this is called free pier.

26. Some other types of bridge piers Hammerhead piers It is also called as solid shaft piers. It have a single solid concrete cross section that support the cap. In this pier, it is seen that the major axis of the pier and the direction of steam flow is approximately same. It is recommended to use circular or small rectangular cross section when the flow is not in the same direction as the major axis. Spread footing are generally used for this type of piers.

27. Hammerhead Pier.

28. Multicolumn or Pile bent It has two or more column that support the cap. There is a problem of debris collection when the water is allowed to flow between the columns. Combined footing may be used where the column spacing is less & isolated footing where the spacing is greater. It also known as frame bent. Multicolumn or Pile bent.

29. Some other special shaped pier.

30. Special Shaped Bent.

31. V Shaped Steel pier

32. Architectural pier. Architectural pier A pier, in architecture, is an upright support for a structure or superstructure such as an arch or bridge. Sections of structural walls between openings (bays) can function as piers.

33. Requirements of Bridge Piers It should effectively transfer loads from Superstructure to foundation without failure. It should withstand all force actions. The material for the piers should be easily available It should have pleasant appearance. Its design should be simple. The piers should be durable against weathering, impacts and corrosion. The cost of construction should be cheap. It should have minimum repair and maintenance cost. It should have stability against the lateral and longitudinal force actions Seismic, Wind, Ice, Currents, Impacts .

34. Typical cross-section shapes of piers.

35. Loads and Force acting on Pier Dead loads. Live loads and impact from the superstructure. Wind loads on the structure and the live loads. Centrifugal force from the superstructure. Longitudinal force from live loads. Drag forces due to the friction at bearings. Earth pressure. Stream flow pressure. Ice pressure. Earthquake forces. Thermal and shrinkage forces. Ship impact forces. Force due to pre-stressing of the superstructure. Forces due to settlement of foundations.

36. Common Reinforcement distribution on pier Normal bar arrangement. Interlocking bar arrangement.

37. 2D view of normal and interlocking bar distribution.

38. Failure of Pier Weld failure of column longitudinal reinforcement, 1995 Kobe Earthquake

39. Shear failure of columns during the 1971 San Fernando earthquake ( Moehle et al., 2000) Fig. 17: Shear failure of a column of Shinkansen bridge. 2004, Japan, ( Moehle et al., 2000).

40. Bond failure of lap slices of bridge pier.

41. Failure for scouring. In river for scouring sometimes the support of pier will removed and this failure be occur, this is called scouring failure of pier.

42. Repair procedures of shear failure. The repair procedures were similar for all the damaged pier specimens and can be summarized as follows: (1) The damaged concrete in and around the damage region should removed, and the pier surface of the damage region cleaned using a high-pressure air gun. (2) The buckled longitudinal bars are straightened by pounding them with a rubber hammer, and then the fractured spiral bars in specimens are welded together using new similar reinforcing bars. (3) Early-strength concrete of damage region is cast, and the surface of the pier specimens is finished to their original shape and dimension. Note: This can be done in flyover bridge pier and building pier. But in river it might not done for due to some limitations.

43. Covering the failure pier with steel. The bonding failure can repair by covering the failure pier by steel materials although it’s costly . And it requires experienced people for work. Repair process of bond failure.

44. Selection criteria of pier. Selections of proper pier type depend upon many factors. First of all, it depends upon the type of superstructure. For example, steel girder superstructures are normally supported by cantilevered piers, whereas the cast-in-place concrete superstructures are normally supported by monolithic bents. Second, it depends upon whether the bridges are over a waterway or not. Pier walls are preferred on river crossings, where debris is a concern and hydraulics dictates it. Multiple pile extension bents are commonly used on slab bridges. Last, the height of piers also dictates the type selection of piers. The taller piers often require hollow cross sections in order to reduce the weight of the substructure. This then reduces the load demands on the costly foundations.

45. References: A.RAHAI and M.AREZOUMANDI The 14 th World Conference on Earthquake Engineering October 12- 17, 2008, Beijing, China “ EFFECT OF VERTICAL MOTION OF EARTHQUAKE ON RC BRIDGE PIER ” Atsuhiko MACHIDA And Khairy H ABDELKAREEM “ EFFECT OF SHEAR REINFORCEMENT ON FAILURE MODE OF RC BRIDGE PIERS SUBJECTED TO STRONG EARTHQUAKE MOTIONS ” Deyuan Zhou, Ruiwen Li, Juan Wang, and Changtuan Guo Received 29 November 2016; Revised 16 April 2017; Accepted 9 May 2017; Published 16 July 2017 Hindawi Shock and Vibration Volume 2017, Article ID 7085392, 12 pages “ Study on Impact Behavior and Impact Force of Bridge Pier Subjected to Vehicle Collision ” Kazuyuki Mizuguchi , Norimasa Higashida , Koji Osada , Gaku Ohashi , “ Design and Construction Highway Piers with Interlocking Hoops in Japan” Jain, J. K.; Saxena , A. K.; and Shrivastava , Sanjay Kumar, "Pier Failure of Bridge and Geotechnical Investigation − A Case Study"(1998). International Conference on Case Histories in Geotechnical Engineering . 11. Engr. Md. Abdur Rahman Bhuiyan , ” Strength and Ductility of Reinforced Concrete Highway Bridge Pier ” National Seminar on Performance Based Design of Reinforced Concrete Structures.