Published on August 13, 2017
1. DEPARTMENT COLUMBIA INSTITUTE OF EGINEERING AND TECHNOLOGY, RAIPUR
2. ANALYSIS OF PRE-STRESSED BRIDGE CONSTRUCTION Guided by:- Mr. K. Durga Prasada Rao civil department Team members KAMAL KISHOR NITESH KUMAR VERMA PRASHANT DIWAN VINAY ALOK MAKHIJA DEEPAK SHORI
3. What is bridge? A structure built to provide passage over a river, canal, road or any other physical hurdle . The function required from the bridge and the area where it is constructed decides the design of the bridge or A bridge is a structure providing passage over an obstacle without closing the way beneath. or The required passage may be for a road, railway, pedestrians , canal or pipeline.
4. Danyang–Kunshan Grand Bridge in china
5. The world's longest Rail-road Bridge is the Danyang–Kunshan Grand Bridge in China, part of the Beijing-Shanghai High-Speed Railway. The bridge, which is opened in June 2011, spans 102.4 miles (165 kilometers). China constructed the Danyang–Kunshan Grand Bridge in just 4 years, employing 10,000 workers, at a cost of about $ 8.5 million. It crosses low rice paddies, part of the Yangtze River Delta, with just a few miles of the bridge actually crossing the open water of Yangcheng Lake in Suzhou. The bridge elevates about 100 feet (31 meters) off the ground. The world's longest road bridge is the 34-mile (55-km) long Bang Na expressway in Thailand, a six-lane elevated highway that crosses only a bit of water, the Bang Pakong River. Constructing the massive bridge required more than 18,00,000 cubic meters of concrete.
6. 1.Classification of Bridges (According to form (or) type of superstructures) •Slab bridge •Beam bridge •Truss bridge •Arch bridge •Cable stayed (or)suspended bridge
7. 2.Classification of bridges (According to material of construction of superstructure) •Timber bridge •Concrete bridge •Stone bridge •R.C.C bridge •Steel bridge •P.C.C bridge
8. 3. Classification of bridges (According to inter-span relationship) •Simply supported bridge •Cantilever bridge •Continuous bridge
9. 5. Classification of bridges (According to method of connection of different part of superstructures) •Pinned connection bridge •Riveted connection bridge •Welded connection bridge
10. 6.Classification of bridges (According to length of bridge) •Culverts (less than 6 m) •Minor bridges(more than 6 m- less than 60m) •Major bridges(more than 60 m) •Long span bridges(more than 120 m)
11. 7.Classification of bridges (According to function) •Aqueduct (canal over a river) •Viaduct(road or railway over a valley or river) •Pedestrian bridge •Highway bridge •Railway bridge •Road-cum-rail or pipe line bridge
12. What Is Pre-Stressed Concrete Pre-stressed concrete is basically concrete in which internal stresses of a suitable magnitude and distribution are introduced so that the stresses resulting from external loads are counteracted to a desired degree. In reinforced concrete members, the pre-stress is commonly introduced by tensioning the steel reinforcement. The earliest examples of wooden barrel construction by force-fitting of metal bands and shrink-fitting of metal tyres on wooden wheels indicate that the art of pre-stressing has been practiced from ancient times. The tension strength of plain concrete is only a fraction of its compressive strength and the problem of it being deficient in tensile strength appears to have been the driving factor in the development of the composite material known as “reinforced concrete”. *The idea of pre-stressing to counteract the stresses due to loads was first put forward by the Austrian engineer Mandi in 1869. M Koenen, of Germany.
13. Types Of Pre-Stressing • Pre-Tensioning A method of pre-stressing concrete in which the tendons are tensioned before the concrete is placed. In this method, the pre-stress is impacted to concrete by bond between steel and concrete. • Post-Tensioning A method of pre-stressing concrete by tensioning the tendons against hardened concrete. In this method, the pre-stress is impacted to concrete by bearing.
14. What is Post-Tensioning Post-tensioning is a technique used for reinforcing concrete structures . In this technique high tension steel cables placed through plastic ducts or sleeves positioned before the concrete is placed. Afterwards, once the concrete has gained strength but before the service loads are applied, the cables are pulled tight, or tensioned, and anchored against the outer edges of the concrete. Pre-stressing simply means that the steel is stressed (pulled or tensioned) before the concrete has to support the service loads. Most precast, pre stressed concrete is actually pre-tensioned-the steel is pulled before the concrete is poured. Post-tensioned concrete means that the concrete is poured and then the tension is applied-but it is still stressed before the loads are applied so it is still pre stressed.
15. Components of Bridge
16. The various stages of the post-tensioning operation are summarised as follows. 1) Reinforcement and Placement of the tendons (High tension cables). 2) Casting of Bridge Deck. 3) Placement of the anchorage block and jack. 4) Applying tension to the tendons. 5) Seating of the wedges. 6) Cutting of the tendons
17. Post tensioning bridge Hydroullic tensioning jack
18. The essential devices for post-tensioning are as follows. 1) Casting bed 2) Mould /Shuttering 3) Ducts 4) Anchoring devices 5) Jacks 6) Couplers (optional) 7) Grouting equipment (optional).
19. FIELD DATA Construction of HL Bridge across Chhokra nalla on Saddu-Urkura Road Chhokra nalla on Saddu-Urkura Road SPAN NO-A1-P1 1 Area of Strands and value of ‘E’ as per test Report (Actual value) S. No. Coil No. Area of Strands Value of ‘E’ i 819287/3 99.45 mm2 20045.00 Kg/mm2 ii 819287/1 100.26 mm2 20010.00 Kg/mm2 iii 819287/3 99.51 mm2 19985.00 Kg/mm2 Average area 99.740 mm2 20013.33 Kg/mm2 Or 2.00x104 2 Area of Strands and value of ‘E’ as per Drawing No. 132/W/CE/ RYP 2015 Dated 31-03-2015 (i) Area of Strand (A) - 98.7mm2 (ii) Value of ‘E’ - 2.00x104 Kg/mm2 (Modulus of Elasticity) Modified Extension = Design Extension in mm x 98.7 x 2.00 x 104 (Actual area in sq. mm. x Actual (E) in kg/mm2 = Design Elongation X 98.70 x 2.00 x 104 99.923 x1.99 x 104 = Design extension X0.99455
20. 3 Modified Extension Cable group. Cable No. Extension as per Design in mm Modified Extension (mm) D 1,2,3 2 123.000 246.00 244.66 I 4,5,6 2 123.000 246.00 244.66 II 7,8,9 2 123.000 246.00 244.66 III 10,11,12 2 123.500 247.00 245.65 IV 13,14,15 2 123.500 247.00 245.65 V 16,17,18 2 122.000 244.00 242.67 VI 19,20,21 2 122.500 245.00 243.66 VII 22,23 2 75.000 150.00 149.18 VIII 24,25 2 52.000 104.00 103.43 IX 26,27 2 75.000 150.00 149.18 X 28,29 2 52.000 104.00 103.43 4 Calculation of Dial Gauge Reading (i) Force applied in each end as per drawing = 169.4 Tonne 14.11666667 Each cable force = 169.40/12 14.117Tonne (ii) Area of Ram of Jack (as per test certificate) = 482.400 cm2 Pressure on dial gauge = 169400 = 351.1608624 Kg/cm2 482.400 cm2 Say351 Kg/cm2 (a) Maximum Pressure = Design Pressure + 5% = 368.55 Kg/cm2 Say = 369.00kg/cm2 (b) Minimum Pressure = Design Pressure – 5% = 351 x 0.95 = 333.50 Kg/cm2 Say = 334.00 kg/cm2
21. Cable Stressing Testing Results Cable group. Cable No. Modified Elongation Total slip in mm ( 2x6 = 12 mm) Net elongation required in mm Maxi.+ 5% Mini.-5% 1 2 3 4 5 6 D 1,2,3 244.66 -12 232.66 244.29 221.03 I 4,5,6 244.66 -12 232.66 244.29 221.03 II 7,8,9 244.66 -12 232.66 244.29 221.03 III 10,11,12 245.65 -12 233.65 245.34 221.97 IV 13,14,15 245.65 -12 233.65 245.34 221.97 V 16,17,18 242.67 -12 230.67 242.20 219.14 VI 19,20,21 243.66 -12 231.66 243.25 220.08 VII 22,23 149.18 -12 137.18 144.04 130.32 VIII 24,25 103.43 -12 91.43 96.00 86.86 IX 26,27 149.18 -12 137.18 144.04 130.32 X 28,29 103.43 -12 91.43 96.00 86.86
23. Project Scope Location/Survey Final Design Construction Preliminary Design Bridge Design Process •Function (To bridge or not? Replace or remove?) •Who is User? •Where is best spot? •Many decisions. •Project Funding and Scope finalized. •Plans, Specs, Estimates.
24. PRELIMINARY SURVEY In General Bridge Preliminary Survey Involves Topography Catchment area Hydrology Geo-technical data Seismology Construction resources
25. Pile foundation and pile cap Pile foundations are the part of a structure used to carry and transfer the load of the structure to the bearing ground located at some depth below ground surface. The main components of the foundation are the pile cap and the piles. Piles are long and slender members which transfer the load to deeper soil or rock of high bearing capacity avoiding shallow soil of low bearing capacity The main types of materials used for piles are Wood, steel and concrete.
26. Piers of bridge Wherever possible slender piers should be used so that there is sufficient flexibility to allow temperature, shrinkage and creep effects to be transmitted to the abutments without the need for bearings at the piers, or intermediate joints in the deck.
27. Bearing Bridge bearings are devices for transferring loads and movements from the deck to the substructure and foundations. In highway bridge bearings movements are accommodated by the basic mechanisms of internal deformation (elastomeric), sliding (PTFE), or rolling. A large variety of bearings have evolved using various combinations of these mechanisms.
28. Deck Slab of Bridge : Deck Slab is the top most part of the bridge Structure . Which is the major element of the super structure it is directly take load and transfers into columns
29. Joints : The objective is to avoid the use of joints over abutments and piers. Expansion joints are prone to leak and allow the ingress of de-icing salts into the bridge deck and substructure. In general all bridges are made continuous over intermediate supports and decks under 60 metres long with skews not exceeding 30° are made integral with their abutments.
30. Parapet and drainage: Parapet as a safety barrier that is installed on the edge of a bridge or on a retaining wall or similar structure where there is a vertical drop, and which may contain additional protection and restraint for pedestrians and other road users.
31. MATERIALS USED FOR BRIDGE Concrete grade M25 for foundation work (1:1:2)(nominal) M30 for piers (Design mix) M35 girder and deck construction (Design Mix) Concrete is supply by RMC plant ( SKM) Reinforcement bar 6 mm & 8 mm in deck 8 mm & 10 mm in girder 10 mm & 18 mm in piers 10 mm & 25 mm use in piles High tensioned wire for stressing of girder.
32. INTRESTING FACTS ABOUT THE BRIDGE Total length of bridge is 144 meter 72 meter saddu side ,and 72 meter urkura side Deck elevated from ground level is 6 meter. There is 4 span and 3 piers , each span is 35.5 meter long and width of 12 meter. Each piers having 4 piles of 1meter dia. Total estimated cost of bridge is 9 carore but due some delay budget is increased by 14 carore . Bridge under constructed on PWD Raipur. For designing of bridge in working stress method.
33. BRIDGE AFTER COMPLETION