D.V.Bhavanna Rao. M.Tech., F.I.E.,Chief Engineer ,

Roads & Buildings Andhra Pradesh (Retired)

for more presentations on Roads and Bridges, please visit

http://aproadbuildqa.blogspot.combhavanna.r@egis-india.com

Important Aspects in Six Laning of Highways through PPP as per IRC:SP:87-2010

Generala)This manual is applicable for highways from

4 lane to 6 lane through PPP mode. In case ofwidening from 2 lane to 6 lane or new constructionof 6 lane highways, the general planning aspectsmay be different from those given in this manual,but the new 6 lane project highway shall meet thestandards specified in this manual .standards specified in this manual .

b)At least 2 weeks prior to commencement ofwork, concessionaire shall draw up a QualityAssurance Manual covering Quality System, QualityAssurance Plan and documentation of all aspects ofbridge and road works and send 3 copies to the IEfor review. The class of quality assurance shall notbe less tham Q-3 (Refer IRC:SP:47 and IRC:SP:57)

2

Nature of terrain

Cross slope of the

ground

Design speed (km/hour)

Ruling Minimum

Plain and Rolling

Up to 25% 100 80

Design Speed in Km/hour

Rolling

Mountainous and Steep

More than 25%

60 40

Short stretches (say less than 1 km) of varying terrain met with on the road stretch shall not be

taken into consideration while deciding the terrain classification for a given section of a Project

Highway. 3

Right of Way and Lane Width

A minimum Right of way (ROW) should beavailable for development of a 6 lane highway. TheAuthority would acquire additional land required, ifany. The land to be acquired shall be indicated inSchedule B of the Concession Agreement.

Where the alignment of 6 lane Highway is to beWhere the alignment of 6 lane Highway is to beretrofitted on to existing highway, the details ofROW width from centerline of LHS and RHScarriageway(s) shall be provided to theconcessionaire in Schedule A of ConcessionAgreement.

The standard lane width shall be 3.5m. 4

Type of section

Minimum width of median (m)

Plain and rolling terrain

Mountainous and steep terrain

RaisedDepressed

MedianRaised

Open country with isolated 4.5m 7.0m 2.0m

Minimum width of median

with isolated built up area

4.5m 7.0m 2.0m

Built up Area 2.0mNot

applicable2.0m

Approach to grade separated

structures4.5m

Not applicable

2.0m

Type and widths of median at various stretches shal l be as indicated in Schedule B of Concession Agreement. 5

Guidelines for medians

1) They shall have suitably designed drainage systemso that water does not stagnate in the median. All mediandrains shall be of RCC type.

2) in case of depressed median, a minimum 0.6m widthadjacent to carriageway in either direction shall be paved.

3) Uniform width of median is preferred throughout. Inunavoidable cases, a transition of 1 in 20 shall be provided .unavoidable cases, a transition of 1 in 20 shall be provided .

4) For depressed median, metal beam type crashbarriers shall be provided on either side of the median.

5) In case of median width of 2.5m and below or pavedmedians, crash barriers shall be provided and suitable antiglare measures such as plastic screens shall be consideredto reduce headlight glare from opposite traffic. Total heig htof screen including crash barrier shall be 1.5m

6) In case of unpaved median wider than 2.5m, suitableshrubs shall be placed as per section 11 of this manual. 6

Type of SectionWidth of shoulder (m)

Paved Earthen Total

Open country with isolated built up area

1.5m 2.0m 3.5m

Width of shoulders in Plain and Rolling Terrain

isolated built up area

Built up area 2.0m - 2.0m

Approaches to grade separated structures

2.0m - 2.0m

Approaches to bridges 1.5m 2.0m 3.5m

7

Width of Shoulders in mountainous and steep terrain (Hilly Area)

Type of SectionWidth of shoulder (m)

Paved Earthen Total

Open country with isolated built

up area

Hill side

1.5m - 1.5m

Valley 1.5m 1.0m 2.5mup area Valley

side1.5m 1.0m 2.5m

Built up area and approaches to

grade separated structures

Hill side

0.25m + 1.5m(raised)

- 1.75m

Valley side

0.25m + 1.5m(raised)

- 1.75m

Note: In case retaining wall with parapet is provid ed on valley side, earthen shoulders may not be provided 8

Type of shoulders1) In the built up section and approaches to

grade separated structures, the shoulder shall bepaved in full width.

2) Earthen shoulders shall be covered with150mm thick layer of granular material conformingto the requirements given in clause 401 of MORT&HSpecifications .Specifications .

3) In embankments with height more than 6m,the granular shoulder may be raised with provisionto kerb channel to channelize the drainage as anerosion control device.

4) The composition and specifications of thepaved shoulder shall be the same as that of themain carriageway. 9

Extra width of pavement and roadwayIn each carriageway

Radius of curve extra width

75 - 100m 0.9m

101 - 300m 0.6m

The cross fall on straight portions of roadcarriageway, paved shoulders and paved portion ofmedian shall be 2.5% for bituminous surface and 2.0%for CC surface.

Super elevation shall be limited to 7%, if radiusof curve is less than desirable minimum radius. Itshall be limited to 5%,If radius of curve is more thandesirable minimum. 10

Minimum radii of horizontal curves

Nature of terrainDesirable minimum

Absolute minimum

Plain and rolling 400m 250m

Mountainous and steep 150m 75m

The radius of horizontal curves for variousterrain conditions shall not be less than thedesirable minimum given above except forsections as indicated in schedule B. For suchsections, the radius shall not be less thanabsolute minimum. 11

Safe sight Distance

Design Speed Km/hour

Safe Stopping Sight Distance

Desirable minimum sight

distance100 180m 360m80 130m 260m60 90m 180m40 45m 90m

Vertical alignment should provide for asmooth longitudinal profile. Grade changes shall notbe too frequent as to cause kinks and visualdiscontinuities in the profile. IRC: 73 should be keptin view. 12

Ruling and Limited Gradients

Nature of terrain

Ruling gradient

Limiting gradient

Plain and rolling

3.3% 5.0%

Mountainous 5.0% 6.0%

Steep 6.0% 7.0%

Long sweeping vertical curves shall beprovided at all grade changes. These shall bedesigned as square parabolas.

Design of vertical curves and itscoordination with horizontal curves, shall be inaccordance with IRC:SP: 23. 13

Lateral clearance at Underpasses

1) Full roadway width at the approaches shall becarried through the underpass. This width shallnot be less than 12m (7m Carriageway + 2 × 2.5mshoulders) or as indicated in schedule ‘B’.

2) Guardrails/Crash barriers shall be provided forprotection of vehicles from colliding with theabutments and piers and deck of the structures.

3) The width of cattle and /or pedestrian underpassshall not be less than 7m.

14

Vertical clearance at Underpasses

1) For vehicular underpass: 5.5m Minimum

2) For pedestrian and cattle under pass:

3.0m (to be increased to 4.5m in casecertain categories of animals such aselephant/camel are expected to cross theproject highway frequently. This will be asspecified in Schedule ‘B’ of Concessionagreement)

15

Lateral and Vertical clearance at Over pass

Full roadway width shall be carriedthrough the overpass structure unlessotherwise specified in Schedule B. Crashotherwise specified in Schedule B. Crashbarriers shall be provided on abutment sideand on sides of pier to prevent collision.

Vertical clearance at Overpasses: 5.5m minimum at all points of the carriageway.

16

Cattle and pedestrian under/ overpassThese shall be provided as specified in Schedule B.

1) An under/overpass for crossing of cattle and pedestriansmay not be necessary within 2km from vehicularunderpass

2) Width of crossing shall not be less than 7m.3) Pedestrian crossings shall have provision for movementof physically challenged persons.of physically challenged persons.

4) Underpasses shall be preferred to Overpasses5) PUP/ POP shall also be provided within a distance of200m from a school or hospital or factory/ industrialarea.

6) Bus bay along with bus shelter shall be provided at thepedestrian underpass/ overpass location as specified inpara 12.5 of 6-laining manual.

17

Access ControlThere shall be no access to the main highway and

all access shall be from service roads provided on bothsides of the main highway and inter connected throughunderpasses, overpasses or grade separators.

Acceleration deceleration lanes1) length designed for a speed differential of1) length designed for a speed differential of

60kmph.2) width: 5.5m (Minimum)3) Taper at merge; 1 in 15 beyond design length

Median Openin gsMedian openings of not less than 20m shall be

provided for emergency and for repair/ maintenanceworks with detachable guard barrier at a spacing of 5km. 18

Service RoadsFormtion width of service roads shall be minimum

10m. Minimum paved width of service shall be 7m unlessthere is constraint of land width where a minimum width of5.5m would be permissible. Their length and location shall b eincluded in schedule B.

For stretches where bridge length is less than 60m andservice road is required on both sides of stream, serviceroad shall continue across the stream by providing 2-laneroad shall continue across the stream by providing 2-lanebridges.

For bridges length of 60m or more, separate bridgestructures may not be necessary. Service road shall bemerged with Project Highway at 50m before the bridgestructure unless otherwise specified in Schedule B.

Design speed is 40kmph.Service road crust shall bedesigned for 5 MSA of design traffic in 4-laning and for 10MSA in case of 6-laning with design CBR at project site. 19

At Grade InterchangesThere shall be no at-grade intersection of any road

with the main highway, but only with the service road. Theintersection with another NH or SH shall be grade separated.Existing direct intersections shall be closed and remodele daccordingly.

The other intersecting roads shall be designed tofacilitate all movements in following manner;

1) Through overpass/ underpass for crossing project1) Through overpass/ underpass for crossing projecthighway and then right turn through a ramp to merge withproject highway or service road if provided.

2) By merging with service road and crossing throughthe next available vehicular underpass.

There shall be interconnection between the serviceroads of both sides through underpass which will facilitatecross movement of local traffic from one side to the otherside and to facilitate change of direction of through traffi c.

20

Grade Separated Structures

All the details shall be specified in Schedule B.The approach gradient to the grade separatedstructure shall not be steeper than 2.5% (1 in 40).

Geometric design standards for variousGeometric design standards for variouselements of grade separators shall be as per IRC:92

Vehicular under/overpass shall be provided atthe intersection of project highway with NH and SH.Such under/ overpass shall be provided on otherroads carrying Average Daily Traffic of more than5000 PCUs on the date of inviting bids.

21

Important Features to be studied and finalized in Road Embankment design

Design of embankment in cutting or remedial/groundimprovement treatment where necessary as per section 300of MORT&H.

Embankment with height 6m or above shall bedesigned in accordance with IRC: 75 taking into account

Important Features to be studied and finalized in Road Embankment design

Design of embankment in cutting or remedial/groundimprovement treatment where necessary as per section 300of MORT&H.

Embankment with height 6m or above shall bedesigned in accordance with IRC: 75 taking into accountdesigned in accordance with IRC: 75 taking into accountslope stability, bearing capacity, consolidation, settlementand safety considerations.

Side slopes shall not be deeper than 2H:1V unless soilis retained by suitable soil retaining structure.

Side slopes and earthen shoulders shall be protectedagainst erosion by providing a suitable vegetative cover, kerbchannel, chute, stone/cement concrete pitching etc.

Design of pond ash embankment where use of pond isproposed as per IRC:SP:58.

designed in accordance with IRC: 75 taking into accountslope stability, bearing capacity, consolidation, settlementand safety considerations.

Side slopes shall not be deeper than 2H:1V unless soilis retained by suitable soil retaining structure.

Side slopes and earthen shoulders shall be protectedagainst erosion by providing a suitable vegetative cover, kerbchannel, chute, stone/cement concrete pitching etc.

Design of pond ash embankment where use of pond isproposed as per IRC:SP:58. 22

Important Features to be studied and finalized in Road Cut Section design

1) Type of cutting involved and proposedcut slopes.

2) Slope Stability measures like pitchingand breast walls.

Important Features to be studied and finalized in Road Cut Section design

1) Type of cutting involved and proposedcut slopes.

2) Slope Stability measures like pitchingand breast walls.and breast walls.

3) Details of erosion control measures.4) Drainage arrangement to divert

seepage water in case of cut sectionsin hilly terrain like deep side trains.Their slope shall not be flatter than 1 in200.

and breast walls.3) Details of erosion control measures.4) Drainage arrangement to divert

seepage water in case of cut sectionsin hilly terrain like deep side trains.Their slope shall not be flatter than 1 in200. 23

Method of Design of Pavementand design period

1. For flexible pavement, IRC;37 Guidelinesfor design of flexible pavement. Designperiod is 15 years or operation periodperiod is 15 years or operation periodwhichever is more.

2. For Design of Rigid pavement, IRC:58Guidelines for the design of Plain JointedRigid Pavements for Highways. Designperiod is 30 years 24

Flexible Pavement – Design and Strategy

1) Design of flexible pavement for designlife of 15 years or operation period, whicheveris more.

2) Stage Construction:a) Thickness of sub - base and basea) Thickness of sub - base and base

layers for full design period and initialbituminous surfacing for a minimum designperiod of 10 years.

b) Pavement shall be strengthened bybituminous overlay, determined on the basis ofIRC: 81, as and when required to extend thepavement life to full operation period. 25

Rigid Pavement – Design and Strategy

1) Design period: 30 years.2) Pavement Quality Concrete (PQC) shall

rest on Dry Lean Concrete (DLC) sub base of150mm thick.

3) DLC shall meet minimum cement and3) DLC shall meet minimum cement andcompressive strength requirements as specifiedinIRC:SP:49. It shall extend PQC by 0.5m on eitherside.

4) below DLC layer Granular Sub Base (GSB)layer 150 mm thick shall be provided throughoutthe road width. It shall be designed to obtain adrainage coefficient of not less than 30 m per day. 26

Performance Evaluation

1) Roughness of each lane for full lengthshall be measured bi-annually using approvedmethod and equipment.

2) Structural evaluation of the pavement2) Structural evaluation of the pavementshall be made by taking deflectionmeasurements every 5 years in accordancewith the procedure given in IRC:81, unlessneeded earlier for stretches exhibiting severedistress during the operation andmaintenance period. 27

Strengthening of existing pav ements

1) Extent of distress, nature of deficiencyand treatment required shall be assessed.

2) Necessary corrective measures to betaken as per schedule K.

3) Extensively damaged stretches are to3) Extensively damaged stretches are tobe designed as a new pavement.

4) Where the existing pavement built overan untreated expansive/ black cotton soil subgrade shall be treated separately and requirereconstruction.

5) No granular layer shall be providedover an existing bituminous surfacing . 28

Design of Overlay

1) Thickness of overlay shall be assessed on BBDdeflection technique as per IRC:81 and existingstructural layers.

2) Design period shall be the same as specified forthe new pavement.

3) Design traffic will be estimated as per the3) Design traffic will be estimated as per theprocedure described for new pavement.

4) Thickness of bituminous overlay for pavementstrengthening shall not be less than 50 mm BC, afterattending to the requirements of profile correction.

5)Specifications for overlay shall be as specifiedfor bituminous surfacing for pavement section.

6) Design of recycled mix shall conform toMORT&H 517. 29

Paved Shoulders

1) Paved Shoulders shall be provided fora width of 1.5m.

2) If the existing thickness of paved2) If the existing thickness of pavedshoulder, if any, is less than the thickness ofexisting pavement, the paved shoulders shallbe reconstructed to the pavement thicknessin the adjoining carriageway.

30

Construction, Workmanship and Qualityof works shall be as per section 900 ofMORT&H Standard Specifications for Roadand Bridge works.

In case of premature distress in the formof cracking, rutting, patching, loss of camberor any other structural or functional distress,necessary remedial measures shall beundertaken for conforming to the minimumrequirements prescribed in schedule K of CA.In case of repetition of distress,reconstruction shall be resorted to afterproper investigations. 31

Surface Drainage

1)The selection of type of road side drains shallbe based on the magnitude and duration of flow. Theyshall be designed on the principles of flow in openchannels.

2) Roadside drains shall not pose any problem totraffic, slopes of cuttings, embankment and pavementtraffic, slopes of cuttings, embankment and pavementstructure.

3) As far as possible, Longitudinal slope shall notbe less than 0.5% for lined drains and 1.0% for unlineddrains. Permissible non-erodible flow velocity forcorresponding earth surface as mentioned in clause 9.4of IRC:SP:42 shall be kept in view.

4) The side slopes of unlined drains shall be asflat as possible and shall not be steeper than 2H:1V.32

Necessity for providing RCC drains

1) When due to space restraint, the drains are located near the toe of embankment or near structures.

2) Drains located in built up areas.3) Flow velocity is more than 0.3m/sec to 1m/sec in silt

and sand: and more than 1.5m/sec in stiff clay.

In built-up areas, covered RCC drains, with removable cover at suitable intervals to desilt the drains, shall be provided.

Drainage system of cross roads shall be maintained. RCC box of sufficient size shall be provided across the cross road to maintain longitudinal drainage along the project highway.

33

Sub-Surface Drains shall be provideda) for lowering the water table for drainage of sub-

grade.b) for drainage of pervious sub-base in situations

where it may not be practicable to extend the sub-base across the shoulder.

c) for control of seepage flowd) for control of capillary riseSub surface drains outside the road pavement shall Sub surface drains outside the road pavement shall

be sealed at the top to avoid percolation of surface water into these drains.

Sub Surface Drains shall be:i) Close jointed perforated pipes or open jointed un-

perforated pipes in trenches with backlfill material around pipes.

ii)Aggregate drains consisting of free draining material in the trench without any pipe. 34

Aggregate Drains

1. The trench for aggregate drain shall be of minimum 300mm width and cut to a depth to expose the granular pavement courses to be drained.

2. Aggregate grading shall be as per table 8 of IRC SP: 42.

3. the aggregate drain shall be provided with a geo-textile wrap to act as filtration and separation layer. 35

Drainage of Embankment with height above 3 m

In high embankments and approaches tobridges, special arrangement for protection of slopesshall provided as per clause 7 of IRC: 42, in order toensure that embankment slopes maintain their shapeduring the monsoon season.

Drainage arrangement shall include provision ofDrainage arrangement shall include provision ofkerb channel at the edges of roadway to channelizethe water, and CC lined chutes along the slopes atdesired intervals to discharge water into sidechannels.

The chute drains and drains at toe of theembankment shall be of Plain Concrete (M15 grade) ,over proper bedding.

36

Median Drainage

The median should have adequate longitudinalslope to the nearest culvert to drain off transversely.

In case the carriageway is sloping towards unkerbed median (wider than 5 m), provision of a centralswale shall be made for the drainage of median. Theswale shall slope longitudinally for drainage, waterswale shall slope longitudinally for drainage, waterintercepted by inlets at intervals and dischargedthrough transverse drains into outlet channel.

Median width 7 m or less shall be turfed or pavedand could be crowned for drainage across thepavement.

In super elevated sections, proper arrangementshall be made without allowing water drain on theother carriageway. 37

Use of geo-textile

a) The sub surface drains may be designedusing appropriate geo-textile to serve thefunctions of filtration and separation.

b) The sub-surface drains can be providedb) The sub-surface drains can be providedwith geotextile either along the trench oraround the pipe or both.

c) The geotextile shall satisfy therequirements of MORT&H clause 702

38

Internal Drainage of Pavement Structure

1) Boxed type construction in which pavement ishoused in earthen shoulders shall not beprovided.

2) The sub-base shall be extended across theshoulders for efficient drainage of pavement.

3) The granular sub-base shall be of proper design3) The granular sub-base shall be of proper designand grading to perform satisfactorily as adrainage layer. The drainage layer shall not havematerial finer than 75micronsize.

4) A suitable filler of granular material or geotextileto act as filtration and separation layer shall beincorporated, where necessary, between sub-grade and sub-base to prevent clogging 39

General Requirements for Structures

1) All bridges shall have independentsuperstructure for each direction of travel unlessotherwise specified in Schedule B. culverts may havesingle or independent superstructure.

2) Viaduct spans shall be provided if the height ofsolid embankment in built -up sections is more than 5m.solid embankment in built -up sections is more than 5m.All bridges shall be high level bridges unless specifiedotherwise in Schedule B of concession Agreement

3) Width of median in the culvert and bridgeportion shall, as far as possible, be kept same as that inapproaches. In case median width is different from thatof approach section due to site constraints, suitabletransition shall be provided near approaches for guidingvehicular traffic. 40

General Requirements for Structures -continued

4) For median in structures portion, a suitablydesigned catch pit shall be provided to collect andcarry discharge from median drain. For bridges, wherethe median is more than 1.2 m wide, it shall be open tosky. Safety barrier on the median side shall besky. Safety barrier on the median side shall beprovided at a clear distance of 0.25 m fromcarriageway edge.

5) Suitable provision shall be made for retainingearth in median portion either by extending abutmentwall or constructing a new retaining wall.

6) Any utility service to be carried by thestructures shall be specified in Schedule B of C.A.

41

7.3 Width of Structures to be providedi) New Culverts: Overall width of all culverts shall be

equal to roadway width of the approaches. Outer most faceof railing/ parapet shall be in line with the outer most edge o fshoulder.

ii) New Bridges:1) Overall width of new bridge with a foot path on left

side shall be same as the roadway width of approaches. Allnew bridges shall have a footpath on left side of the traffic.

2) Crash barrier (raised kerb in case of bridges in built2) Crash barrier (raised kerb in case of bridges in builtup areas) shall be provided at the edge of the pavedshoulders with 0.25m shy distance.

3) However, in case a separate bridge is being providedfor service road at the same location, then footpath shall beprovided for the bridge on the service road. Overall width ofthe new bridge in such cases will be less than the approachwidth up to the crash barrier at the edge of paved shoulderwith 0.25m shy distance. 42

7.3 iii) Width of Structures – Existing Culverts1. All culverts which are structurally distressed or not

having sufficient vent/size or unsafe for design loadsshall be reconstructed as new structures of standardwidth as per sub-para 7.3 (i).

2. All existing culverts which are not to bereconstructed shall be widened equal to roadwaywidth of the approaches.

3. Culverts and Hume pipe structures shall be widenedto make the standard deck width mentioned sub-para7.3 (i). If the width of additional widening is less than0.5 m on either side, widening may be dispensed withand traffic shall be guided with the help of crashbarriers in a transition of 1 in 20 on either sideapproaches. List of culverts to be reconstructed and/or widened shall be specified in Schedule B of C.A. 43

7.3 (iv) Width of Structures – Existing Bridges1. All bridges which are structurally distressed shall be

reconstructed as new bridges as per sub-para 7.3 (ii).2. Bearings, expansion joints, railings, crash barriers,

wearing surface etc., which are not in sound condition,shall be replaced.

3. If the width of additional widening is 1.0m or less (0.5 mon each side) the widening may be dispensed with andtraffic shall be guided with the help of crash barriers intraffic shall be guided with the help of crash barriers ina transition of 1 in 20 on either side approaches.

4. Bridges having 2-lane carriageway particularly thosewith T-beam/ box type superstructure with well/ pilefoundations, which are in sound condition, may beretained and another 2-lane brdge constructed by theside of existing bridge effectively providing 4-lanebridge for a 3-lane one way approach.

5. List of bridge structures to be constructed and/orwidened shall be specified in Schedule B of C.A.

44

7.7 Culverts and Bridges using pipes

1. RC pipes for culverts and bridges shall be of NP-4type conforming to IS: 458 requirements . Minimumdiameter of pipes for new culverts shall be 1200 mm.

2. Existing culverts of diameter 900 mm and above,which are in sound condition and functioningwhich are in sound condition and functioningsatisfactorily, may be extended using the samediameter pipes. All culverts with pipe diameter lessthan 900 mm shall be replaced with minimum 1200mm diameter. Minimum depth of earth cushion overpipe excluding road crust shall not be less than 600mm for new/ reconstructed/ retained culverts. In caseof insufficient cushion, encasing of pipe in concreteshall be ensured. 45

Safety Barriers

1. For bridges without foot paths, concrete crashbarriers shall be provided at the edge of thecarriageway on all new bridges.

2. The type design for the crash barriers may beadopted as per IRC:5. The design loading for thecrash barriers shall be as per Clause 209.7 of IRC:6.

3. For bridges with foot paths, pedestrian railing shallbe provided on the outer side of footpath.

4. The railings of existing bridges shall be replaced bycrash barriers, where specified in Schedule B ofC.A.

5. Parapets/ Railings of the existing bridges/ culvertsto be repaired/ replaced shall be specified inSchedule B of Concession Agreement (C.A). 46

Road Over Bridge (Road over Rail)

1. Existing ROBs shall be retained with repairs, widened orreconstructed as given in case bridges in Para 7.3(iv).

2. In case the bridge is to be provided over an existing levelcrossing, twin 3-lane bridges shall be constructed with ove rallwidth as given in Sub-Para 7.3 (ii) of this Section. If thealignment of road at the existing railway crossing has skewangle more than 45 degrees, the alignment of road or of pier/angle more than 45 degrees, the alignment of road or of pier/abutment shall be suitably designed to reduce skew angle up t o45 degrees.

3. The horizontal and vertical clearances to be provided sha ll beas per requirement of the Railway authorities.

4. The Concessionaire shall be required to obtain approvals of alldesigns and drawings from the concerned Railway authoritie s.

5. The construction of ROB within the railway boundary shall beunder the supervision of Railway authorities.

6. The approach gradient shall not be steeper than 1 in 40.47

Road under Bridges (Road under Railway line)

1. Full roadway width shall pass below the bridgestructure. The service roads where provided shall becontinued in the bridge portion also.

2. The vertical and lateral clearances shall be as perguidelines given in Section 2 of this Manual.

3. These structures shall be designed to carry railwayloads . The Concessionaire shall be required to obtainloads . The Concessionaire shall be required to obtainapprovals of all designs and drawings from theconcerned Railway authorities. The design ofstructure shall be in accordance with relevantRailway codes.

4. The construction of RUB and its approaches shall becarried out in conformity with the terms specified inthe approval granted by the Railway authorities.

48

Materials

1. All materials to be used in works shall be in conformity wit hthe requirements laid down for relevant item in IRC/ MORTHSpecifications unless otherwise specified in this Section . Ifthe Concessionaire proposes to use any material, which isnot covered in IRC/MORTH Specifications, it shall conform t orelevant Indian Standards, if there are any, or to theInternational Standards. Proprietary products proposed t o beused shall be proven by use in comparable international roadused shall be proven by use in comparable international roadand bridge projects, and shall be supported withauthenticated licensing arrangement with the manufacture r.

2. The Concessionaire shall identify the proposed sources o fmaterials and submit the proposal prior to delivery. If it isfound that proposed sources of supply do not produceuniform and satisfactory products at any time duringexecution, the Concessionaire shall procure acceptablematerials conforming to the specifications from othersources.

49

For manufactured items, Concessionaire shall submit the following details

1. Name of manufacturer and name of product/ process/ system

2. General features of the product/ process/system along with specifications and standards adopted for the product/ process/ system

3. Authenticated copies of license/agreement3. Authenticated copies of license/agreement4. Details of projects where the product/ process/

system has been successfully used5. Limitations, if any6. Acceptance tests and criteria7. Installation and maintenance procedure and

schedule8. Performance warranty. 50

Structural ConcreteThe Concrete for use in structures shall

conform to the provisions in Clauses 302.6 to 302.9of IRC:21 and Section 1700 of MORT&HSpecifications. Wherever High PerformanceConcrete (HPC) is proposed to be used, the sameshall conform to the provisions of IRC:SP:70.Sampling and testing of concrete shall be as perSampling and testing of concrete shall be as perClause 302.10 of IRC:21. Acceptance criteria forconcrete shall conform to Clause 302.11 of IRC:21.

CementAny type of cement specified in IRC:21 may be

used for the works subject to limitations, if any,specified therein.

51

Coarse Aggregates

Before commencement of the works, atleast three samples, in accordance with theprocedure laid down in IS:2430, shall be takenfor each quarry source to ascertain thequality, suitability and fitness of the availablematerial for use in the works. Fresh tests shallbe conducted in case there is any change inthe source or the type of rock being quarried.The proposal, along with a copy of testreports, shall be submitted.

52

Sand/ Fine Aggregates

1. All fine aggregates shall conform to IS:383 andtests for conformity shall be carried out as perIS:2386 (Part I to VIII). The fineness modulus offine aggregates shall be between 2.0 and 3.5.

2. Before the commencement of the works, atleast three samples as per IS:2430 shall be takenleast three samples as per IS:2430 shall be takenfor each quarry source to ascertain the quality,suitability and fitness of the available material foruse in the works and the proposal along with acopy of test reports shall be submitted to the IEfor review and comments, if any.

3. Fine aggregates having positive alkali-silicareaction shall not be used. 53

Water

1. Water for use in the works for mixing andcuring of concrete shall be in conformitywith Clause 302.4 of IRC:21.

2. Water from each source shall be tested2. Water from each source shall be testedbefore the start of works and thereafterevery three months and after eachmonsoon till the completion of the worksand the proposal along with a copy of testreports submitted to the IndependentEngineer for review and comments, if any.

54

Chemical Admixtures1. Shall comply with IS:9103 and meet the requirements stipu lated

in clause 5.5 of IS:456.2. Admixtures generating hydrogen or nitrogen or containin g

nitrates, sulphides, sulphates, or any other material liab le toaffect the reinforcement/ embedment or concrete shall not b eused.

3. Compatibility of admixture with the cement being used sha ll betested before actual use in the works.

4. Admixtures shall not impair the durability of concrete . They4. Admixtures shall not impair the durability of concrete . Theyshall not combine with the ingredients to form harmfulcompounds or endanger the protection of reinforcementagainst corrosion.

5. The packaging of admixtures shall clearly indicate the na me ofthe manufacturer/ supplier, brand name (name of the product ),date of production and expiry, batch/ identification numbe r.

6. pH value and colour.7. Latest date of test and name of the laboratory.8. Shelf life, maximum and minimum temperature for storage,

precautions to be taken while mixing etc., in use.55

Steel for Prestressing

In addition to the requirement mentioned inClause 1009.2 of MORTH Specifications, the steel forPrestressing shall satisfy following conditions:(i)Uncoated stress relieved low relaxation steelconforming to IS:14268.(ii) Prestressing steel shall be subjected to(ii) Prestressing steel shall be subjected toacceptance tests in respect of modulus of elasticity,relaxation loss at 1000 hrs, minimum ultimate tensilestrength, stress- strain curve etc. prior to actual useon works as per guidelines contained in BS:4447.The modulus of elasticity value, as per acceptancetests, shall conform to the design value, which shallbe within a range not more than 5 per cent betweenthe maximum and the minimum .

56

Reinforcement/ Un-tensioned Steel1. Only Fe 500 grade of steel shall be used on works and all

reinforcing steel for use in works shall be procured from mai n/major producers. Fe 415 grade of steel can also be used wherepermissible as per IRC Codes and Guidelines.

2. Only fresh steel shall be brought to the site. Every bar sha ll beinspected before assembling on the work; and defective, bri ttle orburnt bars shall be discarded. Cracked ends of bars shall be c utbefore use.

3. Only Thermo Mechanically Treated (TMT) bars conforming t oIS:1786 shall be used as reinforcing steel .IS:1786 shall be used as reinforcing steel .

4. All reinforcement shall be free from loose rust and coats o f paints,oil, mud or any other substance, which may destroy or reducebond. The reinforcement bars bent and fixed in position shal l befree from loose rust or scales, coats of paints, oil, mud or ch loridecontamination and other corrosion products. Where cleanin g ofcorroded portions is required, proposal for effective meth od ofcleaning such as sand blasting shall be submitted to the IE fo rprior review and comments.

5. Proprietary steel products will be permissible provided theyconform to the minimum requirements .

57

Steel for BearingsMild steel, high tensile steel, cast steel,

steel forgings, and stainless steel shallconform to the provisions contained in clause925.1 of IRC:83 (Part III).

Structural SteelStructural SteelAll structural steel, castings and

forgings, fasteners (bolts, nuts, washers andrivets), welding consumables and wire ropesand cables shall conform to the provisions ofclause 505.1.2, 505.2, 505.3, 505.4 and 505.6respectively of IRC:24. 58

BitumenBitumen shall be paving bitumen of

viscosity grade complying with Indian StandardSpecifications for “Paving bitumen” IS:73:2006of grade appropriate for the traffic and climaticconditions of the Project Highway. The heavilytrafficked roads in hot areas may find hardertrafficked roads in hot areas may find hardergrade bitumen more appropriate whilepavements in mountainous regions subject tosub-zero temperatures during winter monthscarrying relatively lower traffic loads and subjectto the phenomenon of “Frost Heave” may findless viscous bitumen resistant to fatigue andcold cracking more appropriate. 59

Storage of MaterialsAll materials shall be stored at proper

places so as to prevent their deterioration orintrusion of foreign matter and to ensure thepreservation of their quality and fitness forthe work. Any material, which has deterioratedor has been damaged or is otherwiseor has been damaged or is otherwiseconsidered defective after review by theIndependent Engineer shall not be used in theworks and shall be removed from site by theConcessionaire at his cost. Such materialsshall not be made acceptable by anymodifications. 60