Presentation on rating & strengthening of bridges @ jntu hyd by raghavendra
Download as PPT, PDF2 likes1,390 views
The document outlines the process and methodology for rating the safety and load-bearing capacity of bridges, detailing various rating methods such as analytical, correlation, and load test methods. It includes procedures for calculating safe axle loads, strengthening techniques, and posting restrictions to ensure bridge safety. The conclusion emphasizes the importance of proper rating to prevent accidents and supports follow-up actions like repairs or demolitions as necessary.
![BONDING OF CFRP
PLATES :
Test results
Test Specimen Fbr [KN] Ybr [mm] Εbr
Specimen 1 Curing 161 70 6.61
without oscillation
Specimen 4 176 75 6.55
Curing with oscillation](https://image.slidesharecdn.com/presentationonratingstrengtheningofbridgesjntu-hydbyraghavendra-130401154604-phpapp01/85/Presentation-on-rating-strengthening-of-bridges-jntu-hyd-by-raghavendra-11-320.jpg)
Presentation on rating & strengthening of bridges @ jntu hyd by raghavendra
- 1. JNTU COLLEGE OF ENGINEERING, ANANTAPUR. PRESENTATION BY…. R.RAGHAVENDRA K.MADHAVULU III/IV B.Tech, Civil III/IV B.Tech, Civil
- 2. CONTENTS : 1. SCOPE 2. RATING METHODOLOGY 3. PROCEDURE FOR RATING 4. STRENGTHENING 5. POSTING 6. CONCLUSION 7. REFERENCES
- 3. SCOPE : INTRODUCTION… RATING… NECESSITY OF RATING… LOADS FOR RATING… Poor quality * DEAD LOAD * LIVE LOAD * IMPACT
- 4. RATING METHODOLOGY: GLOBAL PRACTICES LOADS STRESSES FATIGUE DESIGN PHILOSOPHY RATIING SYSTEM ANALYTICAL METHOD CORRELATION METHOD LOAD TEST METHOD
- 5. ANALYTICAL METHOD It is applicable when as built or contract drawings and specifications followed are available or when such drawings can be prepared by site measurements to an acceptable level of accuracy. CORRELATION METHOD This method is adopted when the safe carrying capacity of structure can be ascertained by correlating the sectional details of the DIFFERENT GRAPHS USED IN METHOD structure.
- 6. LOAD TEST METHOD It is applicable when no construction drawings and specification originally followed are available or when such details are not possible to be obtained an site. PROOF TEST FAILURE TEST VEHICLES FOR TESTING Test vehicles are chosen such that they are the next heaviest vehicle than the predominant heavy load presently passing over the bridge.
- 7. Study all available data, Detailed field or Where drawing, etc. lab investigation • Mcap : Moment resisting Compute section capacity in moment and shear at selected location Assess capacity of selected section. reduction factor (η) • Vcap : Shear resisting Compute Mcap and Vcap capacity at selected section. Compute effect of all loads • MDL and VDL : Moment and other than live loads at selected shear of all loads other than Compute MLL = ηMcap – MDL VLL = ηVcap – VDL At live loads at selected section. selected locations • MLL and VLL : Net resisting Compute maximum LL capacity minus effect due to moment and shear at selected locations all loads other than live loads. • MLL and VLL : maximum Compare Bridge rated For MLL ~ MLL corresponding IRC possible effect (moment and standard Live VLL ~ VLL Loading hear) including impact effect.
- 8. SPACING AND NUMBER OF VEHILES Closer spacing of vehicles in urban areas is a frequent possibility. Urban traffic is mixed and slow as against the heavy and fast traffic for which the rating is proposed and high impact percentage. SINGLE LANE BRIDGE SPACING Standard and heavy trucks 30 Mt Articulated vehicles 18.5Mt DOUBLE LANE BRIDGE Double lane bridges are those with carriageway width above 5.5m and up to 7.5 m for all spans. Vehicle arrangement
- 9. PROCEDURE FOR RATING CALCULATION OF SAFE AXEL LOAD RATING OF BRIDGES (IRC S.P.67) CLASS FOUR SIX CLASS FOR MORE WHEELERS WHEELERS THAN 6 MAX. SINGLE MAX. WHEELERS AXLE LOAD SINGLE AXLE MAX. SINGLE LOAD AXLE LOAD 3R 1.1 t 1.0 t 30 R 14.0 t 5R 3.4 t 2.2 t 16.0 t 40 R 9R 5.8 t 3.5 t 17.5 t 50 R 12 R 7.5 t 4.8 t 19.0 t 60 R 18 R 10.0 t 7.6 t 20.0 t 70 R 24 R 12.0 t 8.5 t
- 10. STRENGTHENING : ADDITION OF UNSTRESSED OR PRE-SRTESSED STEEL INSTALLATION OF EXTERNAL PRE-STRESSED REINFORCEMENT BONDED REINFORCEMENT INCREASE OF THE CONCRETE CROSS-SECTION CARBODUR CFRP PLATE SYSTEMS IT CONSIST OF CARBON FIBER Material properties of carbodur CFRP plates E – Modulus Tensile Strength Elongation @ Break N/mm2 N/mm2 Carbodur S 165’000 2’800 > 1.7 Carbodur M 210’000 2’800 > 1.35 Carbodur H 300’000 1’350 > 0.45
- 11. BONDING OF CFRP PLATES : Test results Test Specimen Fbr [KN] Ybr [mm] Εbr Specimen 1 Curing 161 70 6.61 without oscillation Specimen 4 176 75 6.55 Curing with oscillation
- 12. POSTING Posting is a method to restrict the loading on the existing bridge. CONDITION POSTING RATING > LOAD NOT REQUIRED RATING < LOAD REQUIRED TRAFFIC RESTRICTIONS 8 SPEED RESTRICTION 8 FOOT PATH LOADING 8 GEOMETRIC RESTRICTIION ALTERNATIVES TO POSTING 8 FRAME BARRIERS 8 FREQUENT INSPECTION 8 LANE LIMITS 8 REPAIR
- 13. POSTING SIGN Regulatory signs are installed on either Side of bridge ENFORCEMENT Restrictions in respect of Max. load, Geometrical limits, Speed for safety of brides.
- 14. CONCLUSIO • N : Rating helps to determine the safe carrying capacity of bridges, thus the structure can be made safe for use. • Accidents can be avoided due to collapse of the old bridges which have undergone deterioration by posting. • Follow-up actions can be taken according the rating of bridge such as and this current or future loading on the bridge repairs strengthening or demolition of old bridge and construction of new bridge.
- 15. REFERENCES : * Bridge Engineering – D.R.Phatak * WWW.GOOGLE.COM * WWW.ALTAVISTA.COM * Public works department, Nasik * Indian Road congress, Special Publication 37
- 16. ? R.RAGHAVENDRA