Field data req1234 324324 uired_2.1.25.pptx

Yes

1. Report of field data format for HLB 1. Index Map Topo sheet from Survey of India - Scale -1:50,000 - show the proposed location of the bridge. 2. Key Map A2 size - showing the location of the bridge with respect to road km. 3. A KML/KMZ file has to be created for the proposed bridge alignment location. 4. Site Plan Scale -1:1000 – Extending not less than 100m on U/S and D/S and covering the approaches to a distance of not less than about 500m on either side. Showing bore location and TBM.

2. 5. Longitudinal Section along the alignment Horizontal Scale -1:1000, Vertical Scale – 1:100. 6. Longitudinal Section of the Stream Horizontal Scale -1:1000, Vertical Scale – 1:100. 7. Cross Section of the Stream, Horizontal Scale -1:1000, Vertical Scale – 1:100. At least 4 cross sections, each on U/S and D/S and one at site(approximately at 50m intervals ). **Drone videos and photos showing the river course on U/S and U/S for 500 m and also approach along the alignment on either sides.

3. 8. Sub surface exploration Report All bore report shall be verified and signed by the concerned Divisional Engineer. Bore report should have Reduced Level, Date of commencement and ending of bore, chainage , Ground water table level and as per as per IRC:78-2024. 9 . Combined Bore Chart A chart showing all the bores with the strata encountered along with their Reduced levels, depth of each strata, bore termination levels with chainages of each bore. 10 . General Arrangement Drawing Drawing showing the proposed and existing longitudinal profile, sill level, MFL, BOD and TBM .

4. 11.Specification report for high level bridges Name of Work (As per GO). Change in nomenclature, if any. Scheme and Authority The scheme under which the work is taken up. G.O number and date. AS amount   Location and classification of road Location of the bridge with respect to road km. Latitude and Longitude. Drone video & photos shall be attached in the proposal Classification of road (union road/ ODR/ MDR/SH) Maintaining authority.

5. Necessity Brief description of the necessity of the bridge. Whether unbridged or bridged crossing. Rainfall data. Cost benefit ratio. If bridged, Duration of interruptions in hours at a time due to overflow. Number of interruptions in a year.  

6. Details of existing bridges at site, Nearby bridges on U/S and D/S and in the approaches Year of construction and condition. Type of bridge Span arrangement. Carriageway/ Roadway. Type of super structure, sub structure and depth & type of foundation. Sill level, MFL level, BOD level, depth of flow, bed width, length of bridge, road level etc., (Discharge should be for the past 100 years data should be considered ). Benchmark with respect to Mean Sea Level. Photographs of the bridges such as U/S side, D/S side, bottom of deck, side faces and foundation, aprons, if any. Details of PWD structures in the vicinity. Flow obstructions like trees, outcrops, structures, deposits. Observed scour level. Digital FMB sketch of river for 500m on both U/S and D/S side. Bund to bund width of the river course.

7. Alignment selection criteria: The reach of the river upstream and downstream should be straight. The channel in the reach should be well defined and as narrow as possible. The average depth of flow should, in general, be large in comparison with maximum depth of flow. Firm, high and stable bunds which are fairly in-erodible shall be preferred. Right angle crossing is always preferred. This crossing offers minimum possible length and reduces chances of obliquity of flow with respect to the substructure. Crossing involving skew angle more than 30° shall preferably be avoided (as per cl. 105.3.3 of IRC-5-2015). Alignment shall not be selected at locations where the river changes its course or in bends. The site should be free from obstructions in river bed both on U/S and D/S Selection of site should also be away from confluence of tributaries.

8. The approaches on either side of the bridge shall have the same horizontal profile as that provided for the bridge for at least 15m.   Alignment shall consist of minimum number of curves. Sharp horizontal curves, broken back curves and reverse curves should be avoided as far as possible. Alignment should avoid forest land, archeological sites and water bodies. While forming alignment for HLB avoid super elevation, extra widening & longitudinal gradient. Three feasible alignments should be studied with merits and demerits and the best should be approved. Approved alignment including approaches by the alignment committee with date and recommendations of the committee with merits and demerits. Road safety audit to be performed in ease of curves in approach in the approved alignment.

9. Descriptive features of Approved Alignment. Total length, starting and ending chainages of alignment. Bund to bund width of the river course. Details of canals/any water bodies, if any crossing the alignment away from river course. If junction is present closer to the bridge approach, suitable junction improvement proposal along with alignment approval. Tower line, Pipeline crossing the alignment and other utilities etc. for designing the foundation.

10. Bench Mark RL taken on any of permanent structure located nearby. Exposure Based on humidity as per IRC: 112 - 2020. Distance from sea coast. Seismic zone

11. Hydraulic particulars Discharge, velocity, Maximum Flood Level, Sill level, Bund level and Depth of flow, bed slope, Bed width shall be o btained from the WRD authorities of rank not lower than Executive Engineer Discharge calculation using Area velocity method. Large Variation if any in WRD and AV method discharge shall be justified. FMB sketch showing the bed width at site. Discharge to be considered from the catchment area. Catchment area to be marked in topo sheet digitally. Any water body joining/ diverging the river in the U/S or D/S nearby . The Linear Water Way required as per design discharge (in m). Vertical clearance as per IRC 5 and also based on the approaches on either sides. Bridge width should be minimum of FMB width of river. Expert opinion from the hydrologist may be obtained in case of complicated works.

12. Scour depth Observed Scour level during past flood shall be reported. Calculation as per IRC:78-2024 For SDR, particle size with unwashed sample has to be reported with photos

13. Sub soil particulars Sub soil particulars shall be taken with reference to the permanent bench mark . The number of bores shall not be less than 4 for any work or at every 20m. If there is a substantial variation between any two adjacent bores then extra bores are required at midpoint of those two bores. Bore log chart and test results of the samples separately for each borehole. Videos and photos of all bore holes and samples should be attached.

14. The sub soil report shall comprise, Field test results. Lab test results. Abstract of the results. Combined bore chart. Check list. D uring boring undisturbed samples shall be collected and necessary testing has to be conducted. Soil test results shall be obtained preferably from HRS with cohesion and angle of internal friction values. The classification of SDR/Weathered rock shall be categorised based on core recovery. Generally for hard stratum N value is reported as greater than 50. Instead the penetration value in ‘mm’ corresponding to number of blows shall be reported.

15. Termination of Bore (as per IRC:78-2024 Part-I) Soil strata Depth in ‘m’ N-Value Weak rock 10 <200 Moderate rock 5 200 – 600 Hard rock 3 >600

16. Proposal in general 1. Type of bridge   2. Type of Superstructure   3. No. of spans   4. Crossing (Square/Skew)   5. Angle of skew   6. Carriageway   7. Overall width of road way   8. Footpath (Yes/No)   9. Span – C/C of expansion joint   10. Effective span   11. Overall span   12.Length of the Bridge (C/C of exp. Jt.)   13. Lowest bed level   14. MFL   15. Afflux   16. Vertical clearance   17. Bottom of deck   18. Depth of superstructure   19.Finished Road level @ centre  

17. Other details…. Protective Works Necessary protective works such as river training works, quadrant revetment, side slope revetment , guide bund etc., shall be provided as warranted by site conditions. Land acquisition details. Diversion road . Dressing the bed upto sill level - Quantity to be given by execution wing. Rock outcrops if any in U/S or D/S for minimum of 50m to be removed. Dismantling of existing structure – Quantity to be given by execution wing. Other specific condition if any. NOC from WRD for length of bridge & MFL. If there is any dismantling required at the site , quantity has to be furnished to design wing and the same will be included in the estimate. The quantity corresponding to the dressing the bed up to sill level shall be furnished to Design wing and actual quantity will be included in the estimate. If linear waterway is more than 150m, the bridge proposal shall be placed in the Technical Audit Committee as per the minutes of 179 th BOE, dated: 03.02.2022.