ASSESSMENT OF RESIDUAL LIFE OF GIRDERS OF BRIDGE No

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EXEC. DIRECTOR (WORKS) D.O. No. 2004/WI/WR/Girder New Delhi – dt. 30.04.2004 Dear Shri R. K. Gupta, Sub: Alternate use of released steel girders of Vasai Creek bridges on Borivali – Virar section of Western Railway. On Borivali – Virar section of Western Railway, Bridge No. 73 & 75 across Vasai Creek have been newly constructed. The old bridges built in 1916 have been abandoned. Member Engineering , has desired that a study may be conducted on the residual life of the released girders of the old bridges and also the extent of strengthening required with a view to use them on new branch lines where the traffic is going to be light in the beginning. A report prepared by Western Railway on this issue is enclosed herewith for considerations. In view of the above, I would request you to take up the study and submit report including cost of strengthening and loading standard permissible for these released girders for further consideration of the Board. With regards, Shri R. K. Gupta, Executive Director/B&S, RDSO, Lucknow. 22 Yours sincerely Sd/- (P. K. SANGHI) Annexure ABANDONED STEEL BRIDGE ON VASAI CREEK IN CCG – VR SECTION OF MUMBAI SUBURBAN.
1. The Vasai Creek is spanned by bridge nos. 73 & 75 in CCG – VR section of Mumbai Division on Western Railway. The Creek is in tidal zone, experiencing rise and fall in water level but the riverbed is never dry. 2. HISTORY: The abandoned bridge in question, which was in fact the second bridge, was opened for traffic on 22.01.1927. The bridge was built 122 feet (36.5 m) East of the first bridge. The bridge was designed to BG standard of loading 1916. The piers consisted of 6 nos. piles at 9 feet c/c spacing with 3 feet and 2.5 feet dia piles and had provision for future quadrupling . The substructure consists of fish bellied plate girders of 60 feet (18.3 m) span. There were 69 spans in south creek and 25 spans in north creek. There were 6.1 m span at either approach of the two bridges. The bridge was studied by RDSO in 1969 and was found to be weak in foundation and the CI piles and bolts were found to be overstressed . Subsequently, extensive field trials were conducted in association with IIT Bombay and based on same construction of new bridge was included in railway budget of 1981-82. The reasons for abandoning the bridge were as follows: a) The bridge being located on Bombay-Delhi Rajdhani trunk route, where double heading of locomotive was essential, the bridge was not found to be fit for normal speed. Even for the existing load, the foundation and the substructure stresses were found to be exceeded permissible limits requiring heavy speed restrictions. b) A number of CI piles were cracked and were continuing in service of clamps. c) Due to standing water at all times at the bridge location, the foundation could not be inspected thoroughly. There was heavy incrustation in the piles due to marine growth and the same indicated extensive loss of section. d) The most important and critical reason was that due to heavy sand dredging in the creek which was the most important source of sand for Bombay peninsula, the bed level from 1927 had gone down by 8 feet (2.45 m) and the pile grip in rock was reduced to near unsafe limits in some cases. In replacement of the bridge, new bridge was constructed on well foundations at an average depth of 29 m below the mean tidal level and PSC box type girders 65.10 m east of the second bridge and consisted of 1 x 20 m + 28 x 48.5 m PSC Box spans in bridge No. 73 and 11 x 48.5 m PSC box spans in bridge No. 75. The bridge was opened to traffic in year May 1993. 23
Page 1 and 2: Ministry of Railways Government of
Page 3 and 4: INDEX S.No Contents Page no. 1. Int
Page 5 and 6: 11x 48.5 m spans in bridge No. 75 w
Page 7 and 8: d) The fatigue life of standard spa
Page 9 and 10: slowly before failure, which shows
Page 11 and 12: k1 = ------------------------------
Page 13 and 14: Life = 120 / k1 m = 594 years Remai
Page 15 and 16: 15 Table -1 RU Loading : Annual tra
Page 17 and 18: Year GMT during the GMT Cum. GMT du
Page 19 and 20: Stress range in N per sq mm 1000 10
Page 21: No. of cycles 70 60 50 40 30 20 10
Page 25 and 26: vii) The girders are having sliding
Page 27 and 28: WEIGHT CALCULATION Calculation shee
Page 29: REFERENCES: 29 Annexure - III 1. Es

ASSESSMENT OF RESIDUAL LIFE OF GIRDERS OF BRIDGE No

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