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SPECIFICATION FOR CIVILWORKS OF AIR COOLED

CONDENSER

PROJECT1 x 300 MW COAL BASED THERMAL POWER

PLANT, CHHATTISGARH, INDIA

Doc. No. 11V02-201-SPC-M-0001, REV.P0

Date: 04-11-2011 VOL-IIPART-D Page 1 of 58

VOLUME-II

PART-D

CIVIL AND STRUCTURAL

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VOLUME-II, PART-DCIVIL AND STRUCTURAL

I N D E X

A. GENERAL

CLAUSE NO. DESCRIPTION

1.00.00 INTRODUCTION AND SCOPE

2.00.00 CODES & STANDARDS

3.00.00 LAY OUT

4.00.00 SITE DEVELOPMENT

5.00.00 TYPE OF CONSTRUCTION

6.00.00 TECHNICAL SPECIFICATIONS

7.00.00 WORKMANSHIP

8.00.00 TEMPORARY WORK

9.00.00 DOCUMENT SUBMISSION

10.00.00 SEQUENCE OF WORK

11.00.00 MISCELLANEOUS

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B. SPECIFIC DESIGN REQUIREMENT (CIVIL)

1.00.00 LOADS AND LOAD COMBINATION

2.00.00 MACHINE FOUNDATIONS

3.00.00 STABILITY OF STRUCTURES

4.00.00 REINFORCED CONCRETE STRUCTURES ANDFOUNDATIONS

5.00.00 MATERIALS

6.00.00 FORM WORK REQUIREMENTS

7.00.00 STEEL STRUCTURES

C. RATE SCHEDULE

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CIVIL, STRUCTURAL & ARCHITECTURAL WORK

A. GENERAL

1.00.00 INTRODUCTION AND SCOPE

This specification covers design, engineering and construction of Civil,Structural and Architectural works associated with the super structure of AirCooled Condenser. The scope of works covers design, Engineering andconstruction of complete Civil, Structural and Architectural Works includingissue of drawings, etc complete as required for successful completion of theworks in all respects.

This section lists Codes and Standards to be adopted in design andconstruction. Documents to be submitted have also been brought out in thissection along with the procedure to be followed for the same.

Scope of work includes supply of all construction materials like cement,reinforcement steel, structural steel and all materials required for completingthe work.

The work to be performed under this specification consists of design,engineering and providing all labour, materials, consumables, plants,equipment, temporary works, temporary storage sheds, temporary colony for

labour and staff, temporary site offices, constructional plants, fuel supply,transportation and all incidental items not specifically mentioned butreasonably implied or necessary for the completion and proper functioning ofthe plant, all in strict conformance with the specifications, including revisionsand amendments thereto, as may be required during the execution of thework.

The scope of work includes design, preparation of general arrangementdrawings, construction and fabrication drawings, supply of labour, materialsand construction, fabrication and erection of civil, structural and architecturalfacilities.

The scope of civil, structural and architectural work comprise completeengineering, civil/ structural and architectural design, preparation of design andconstruction drawings, submission of design documents for approval, designbasis reports, including issue of all Civil, Structural and Architectural drawingsfor Air Cooled Condenser, miscellaneous related services and facilitiesrequired for completion of the work including but not limited to the following.

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a) Complete Design, Engineering of super structure for Air cooled condensersystem.

b) Preparation of drawings showing loading data for foundations, floors andsupporting structures of all the equipments and systems.

c) Detail analysis and design of the structures, civil construction drawingswith bar bending schedule, structural steel design drawings, fabricationdrawings with bill of material, preparation of the erectiondrawings/scheme, preparation of a schedule ofinserts/embedment/sleeves and a schedule of finishes required includingspecial protective paints if any and preparation of As built drawings aftercompletion of works .

d) Preparation of specifications for construction and construction material,

quality assurance plan (QAP), field quality plan (FQP), testing andacceptance criteria, structure wise Bill Of Quantity (BOQ) including theitems of architectural works.

c) It may be noted that the foundation system of this ACC is being provided bypurchaser. All foundation loading data, equipment load data and otherinformation required for design and construction of foundation of ACCsystem shall be provided to purchaser as required by contractor.

d) ACC super structure shall be of RCC framed system comprising of RCCcolumns and tie beams. ACC fan deck shall be of structural steel system.RCC super structure shall be designed by bidder and will be constructed by

purchaser. The structural steel platform and steel staircases will bedesigned and constructed by bidder.

e) Provision of floor / grating at working platform with hand rails and access asrequired.

f) Civil works related to grouting.

g) Provision of platforms / walkways as required.

The design criteria and Technical Specifications to be followed for design and

construction of civil, structural and architectural work are included hereunder.

This Section lists Codes and Standards to be adopted and the principalstructures of the plant and briefly describes the basic concept, requirementsand features pertinent to each documents to be submitted have also beenbrought out in this section along with the procedure to be followed for thesame.

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2.00.00 CODES AND STANDARDS

Following is a general listing of Codes and Standards to be used in the designof the Plant. Specific applicable codes and standards will be identified inSystem Design Descriptions/Technical Specifications as appropriate. Thelatest editions/revision of following codes and standards along withaddendums/ amendments, if any, shall be followed :

2.01.00 General

a) Internationally accepted design Codes and Standards which are equivalentor more stringent than corresponding Indian Standards.

b) National Building Code of India.

c) "Accepted Standards" and "Good Practice" listed in the appendix toNational Building Code of India.

d) IS-1200 : Method of measurement of Building and CivilEngineering Works.

e) IS-1256 : Code of Practice for Building Bylaws.

2.01.01 Earthwork

a) IS-1498 : Classification and identification of soils for GeneralEngineering purposes.

b) IS-3764 : Safety Code for excavation work.

c) IS-7293 : Safety Code for working with constructionmachinery.

2.01.02 Concrete

a) IS-269 : Ordinary Portland Cement - 33 Grade.

b) IS-383 : Coarse and fine aggregate from natural sources forconcrete.

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c) IS-432 : Mild Steel and medium tensile steel bars and harddrawn steel wire for concrete reinforcement.

d) IS-455 : Portland Slag Cement.

e) IS-456 : Code of Practice for Plain and reinforced concrete.

f) IS-460 : Test Sieves (all parts).

g) IS-516 : Methods of test for strength of concrete.

h) IS-1199 : Methods of sampling& analysis of concrete.

i) IS-1489 : Portland Pozzolona Cement.

j) IS-1566 : Hard drawn steel wire fabric for concreteReinforcement.

k) IS-1786 : High strength deformed steel bars and wires forconcrete reinforcement.

l) IS-1834 : Hot applied sealing compounds for joints inconcrete.

m) IS-2386 : Methods of test for aggregates for concrete (allparts).

n) IS-2502 : Code of practice for bending and fixing of bars forconcrete reinforcement.

o) IS-3370 : Code of practice for concrete structures for storageof liquids (all parts).

p) IS-3414 : Code of practice for design and installation of jointsin buildings.

q) IS-4948 : Welded steel wire fabrics for general use.

r) IS-6909 : Specification for super sulphate cement.

s) IS-6452 : High Alumina Cement for Structural use.

t) IS-7320 : Concrete slump test apparatus.

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u) IS-7861 : Code of practice for extreme weather concreting (allparts).

v) IS-8041 : Rapid Hardening Portland Cement.

w) IS-8112 : 43 grade ordinary Portland Cement.

x) IS-10262 : Recommended guidelines for concrete mix design.

2.01.03 Foundations

a) IS-1904 : Code of practice for design and construction offoundations in Soils : General requirements

b) IS-2950 : Code of practice for design and construction of raftfoundations.

c) IS-2974 : Code of practice for design and construction ofMachine foundations (all parts).

d) IS-2911 : Code of practice for design and construction of pilefoundation.

e) Standard Specification and code of Practice forRoad Bridges Section VII : Foundation andsubstructure by Indian Road Congress (IRC).

f) IS-9795 : }(Part-I) }

} Cofferdamg) IS-10084 : }

(Part-I) }

2.01.04 Loading

a) IS-875 : Code of practice for design loads (other thanearthquake) for building and structures.

(b) IS:1911 : Schedule of unit weights of building materials.

(c) IS:1893 : Criteria for earthquake resistant design of structure

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2.01.05 Masonry

a) IS-712 : Building limes.

b) IS-1077 : Common Burnt Clay Building Bricks.

c) IS-1127 : Recommendations for dimensions and workmanshipof natural building stones for masonry work.

d) IS-1528 : Methods of sampling and physical tests forrefractory materials.

e) IS-1597 : Code of practice for construction of stone masonry(all parts).

f) IS-2212 : Code of practice for brickwork.

g) IS-2116 : Sand for masonry mortars

h) IS-2185 : Concrete masonry units.(all parts - Hollow and Solid concrete blocks).

i) IS-2250 : Code of practice for preparation and use of masonrymortars.

j) IS-2572 : Code of practice for construction of hollow concreteblock masonry.

k) IS-2691 : Burnt clay facing bricks.

l) IS-3414 : Code of practice for design and installation of jointsin buildings.

m) IS-3495 : Methods of tests of burnt clay building bricks.

n) IS-4441 : Code of practice for use of Silicate type chemicalresistant mortars.

o) IS-4860 : Acid Resistant Bricks.

2.01.06 deleted

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2.01.07 Roof and Flooring

a) IS-2204 : Code of practice for construction of reinforcedconcrete shell roof.

b) IS-3201 : Criteria for the design and construction of precasttrusses and purlins.

c) IS-2210 : Criteria for Design of R.C. shell structures and foldedplates.

d) IS-809 : Rubber flooring materials for general purposes.

e) IS-1195 : Bitumen mastic for flooring.

f) IS-1196 : Code of practice for laying bitumen mastic flooring.

g) IS-1198 : Code of practice for laying, fixing and maintenanceof linoleum floors.

h) IS-1237 : Cement concrete flooring tiles.

i) IS-1443 : Code of practice for laying and finishing of cementconcrete flooring tiles.

j) IS-2114 : Code of practice for laying in situ terrazzo floorfinish.

k) IS-2571 : Code of practice for laying in situ cement concreteflooring.

l) IS-5491 : Code of practice for laying in situ granolithicconcrete floor topping.

m) IS-5766 : Code of practice for laying burnt clay brick flooring.

n) IS-1197 : Code of practice for laying of rubber floors.

o) IS-2441 : Code of practice for fixing ceiling coverings.

2.01.08 deleted

2.01.09 Soil Engineering

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a) IS-1498 : Classification and identification of soils for generalengineering purposes.

b) IS-1892 : Code of practice for sub-surface investigation forfoundations.

c) IS-2131 : Method for standard penetration test for soils.

d) IS-2720 : Methods of test for soils (all parts).

2.01.10 Water Supply, Drainage and Sewerage

a) IS-404 : Lead pipes

b) IS-458 : Precast Concrete pipes (with and withoutreinforcement)

c) IS-651 : Salt glazed stoneware pipes and fittings.

d) IS-771 : Glazed fire-clay sanitary appliances (all parts).

e) IS-774 : Flushing cisterns for water closets and urinals (otherthan plastic cisterns).

f) IS-783 : Code of practice for laying of concrete pipes.

g) IS-1172 : Code of basic requirements for water supply,drainage and sanitation.

h) IS-1626 : Asbestos cement building pipes and pipe fittings,gutters and gutter fittings and roofing.

i) IS-1742 : Code of practice for building drainage.

j) IS-2064 : Code of practice for selection, installation andmaintenance of sanitary appliances.

k) IS-2065 : Code of practice for water supply in buildings.

l) IS-2470 : Code of practice for installation of septic tanks (allparts).

m) IS-3114 : Code of practice for laying of Cast Iron pipes.

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n) IS-4127 : Code of practice for laying of glazed stonewarepipes.

o) IS-12251 : Code of practice for Drainage of Building Basement.

p) IS-1200 : Method of measurement : Laying of water and[Part XVI] sewer lines including appurtenant items.

q) IS-1536 : Centrifugally cast (spun) iron pressure pipes forwater, gas and sewage.

r) IS-1537 : Vertically cast iron pressure pipe for water, gas andsewage.

s) IS-3486 : Cast iron spigot and socket drain pipes .

t) IS-5329 : Code of practice for sanitary pipe work aboveground for buildings.

u) IS-3076 : Low density polyethylene pipes for potable watersupplies.

v) IS-1538 : Cast iron fittings for pressure pipes for water, gasand sewage.

w) IS-1230 : Cast iron rainwater pipes and fittings.

x) IS-1729 : Sand cast iron spigot and socket soil, waste andventilating pipes,fittings and accessories.

y) IS-784 : Prestressed concrete pipes.

z) IS-1726 : Cast iron manhole covers and frames.

aa) IS-5961 : Cast iron grating for drainage purposes.

bb) IS-5219 : Cast copper alloys traps : `P' and S' traps,[Part-I]

cc) IS-772 : General requirements for enamelled cast ironsanitary appliances.

dd) IS-775 : Cast iron brackets and supports for wash basins andsinks.

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ee) IS-777 : Glazed earthenware wall tiles.

ff) IS-2548 : Plastic water closet seats and covers (all parts).

gg) IS-2527 : Code of practice for fixing rainwater gutters anddownpipes for roof drainage.

2.01.11 Paving and Road works

a) IS-73 : Paving bitumen

b) IS-702 : Industrial Bitumen

c) IS-1201 : Method of testing tar and bituminous materials.thru' 1220

d) Practice followed by Indian Road Congress (all parts).

2.01.12 Earthquake Resistant Design

a) IS-1893 : Criteria for earthquake resistant design of structures.

b) IS-4326 : Code of practice for earthquake resistant design andconstruction of buildings.

2.01.13 deleted

2.01.14 Structural Steelwork

a) IS-800 : Code of practice for general construction in steel.

b) IS-802 : Code of practice for use of structural steel inOverhead Transmission Line, towers.

Part-I : Load and permissible stresses.

Part-II : Fabrication, Galvanising, Inspectionand Packing.

c) IS-806 : Code of practice for use of steel tubes in generalbuilding construction.

d) IS-808 : Dimensions for hot rolled steel beams, channels andangle sections.

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e) IS-813 : Scheme of symbols for welding.

f) IS-814 : Covered electrodes for manual metal arc welding ofcarbon and carbon manganese steel.

g) IS-816 : Code of practice for use of metal arc welding forgeneral construction in mild steel.

h) IS-817 : Code of practice for training and testing of metal arcwelders.

i) IS-818 : Code of practice for safety and health requirementsin electric and gas welding and cutting operation.

j) IS-819 : Code of practice for Resistance spot welding for lightassemblies in Mild Steel.

k) IS-822 : Code of procedure for inspection of welds.

l) IS-919 : ISO system of limits and fits.

m) IS-1024 : Code of practice for use of welding in Bridges andStructures subjected to Dynamic loading.

n) IS-1161 : Steel tubes for structural purposes.

o) IS-1182 : Recommended practice for RadiographicExamination of Fusion Welded Butt joints in steelplates.

p) IS-1200 : Method of measurement of steelwork and[Part-VIII] ironwork.

q) IS-1239 : Mild steel tubes, tubular and other wrought steelfittings (all parts).

r) IS-1363 : Hexagonal head bolts, screws and nuts of productGrade C' (all parts).

s) IS-1364 : Hexagon head bolts, screws and nuts of productgrades A and B.

t) IS-1365 : Slotted counter sunk head screws.

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[Part-I] approval is not required - Fusion welding of Steel.

mm) IS-8500 : Structural steel micro alloyed (medium and highstrength qualities).

nn) IS-9595 : Recommendation for metal arc welding of carbonand carbon manganese steels.

oo) IS-11592 : Code of practice for selection and design of beltconveyor.

pp) AWS D.1.1 Structural Welding Code.

2.01.15 Painting

a) IS-348 : Specification for French Polish.

b) IS-427 : Specification for Distemper, dry colour as required.

c) IS-428 : Specification for Distemper, oil emulsion, colour asrequired.

d) IS-1477 : Code of practice for painting of ferrous metal in[I & II] buildings.

e) IS-2338 : Code of practice for finishing of wood and wood[I & II] based materials.

f) IS-2339 : Specification for Aluminium Paints for generalpurposes in dual containers.

g) IS-2395 : Code of practice for painting concrete, masonry andplaster surface.

h) IS-2932 : Specification for enamel, synthetic, exterior - a)undercoating, b) finishing.

i) IS-2933 : Specification for enamel, exterior - a) undercoating,b) finishing.

j) IS-5410 : Specification for cement paint.

2.01.06 Bridge and Culvert Work

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a) Indian Road Congress (IRC) Bridge Codes (all parts).

b) Indian Railway Standard Bridge Rules.

3.00.00 LAYOUT

Before starting the work, the Contractor shall carry out the setting out offoundation and structures and provide levels, with reference to general existinggrid and existing Survey of India bench mark. If the Contractor uses the grid,bench mark and reference pillar made by others, he shall satisfy himself of theaccuracy of the reference marks. The Contractor shall accurately set out theposition for holding down bolts and inserts. If he is required to set out thefoundation afresh, he shall do so independently with reference to the oneexisting grid and bench mark which has been followed by other agency at theinstruction of the Engineer. In case any discrepancy be found, it shall beimmediately brought to the notice of the Engineer-in-Charge for anyrectification/ modification necessary. No complaint shall be entertained at alater stage. The Contractor shall accurately set out the position for holdingdown bolts and inserts.

If required, the contractor shall construct and maintain pillars for grid,references and bench marks and maintain them till the completion of theconstruction. He shall also help the Purchaser with instruments, materials andlabours for checking the detailed layouts and levels. The Contractor shall besolely responsible for the correctness of the layout and levels, and Purchaser'sapproval shall not be deemed to imply any warranty in carrying out the workscorrectly. The Contractor shall take into account the cost of these in quotingtheir price.

4.00.00 SITE DEVELOPMENT

4.01.00 Clearing & Grubbing

Clearing and grubbing within all areas where excavation, fill or otherconstruction is planned shall be completed prior to start of such work.

4.02.00 Miscellaneous Work

4.02.01 LightingLighting requirements shall be specified by the bidder and as approved bythe purchaser. Light poles shall be of steel pipes/structural steel/pre-castpoles as per standard developed by the bidder including foundations.

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4.02.02 Water Lines

Water lines may be designed as rigid or flexible conduits as may benecessary. Water lines may be placed in trenches or in fill. When placedin trench, the width of trench shall be 300 mm greater than the size ofpipe upto 300 mm nominal diameter and 400 mm greater for pipes inexcess of 300 mm diameter. The bottom of the trench or the surface ofthe fill shall be accurately graded and shaped to accept the water line.

Selected backfill material shall be placed on both sides of the pipe to anelevation 200 mm above the top of pipe for lines upto 300 mm in diameterand to not less than 150 mm above the horizontal center line of pipehaving a diameter in excess of 300 mm. Compaction of the backfill shallbe in accordance with the recommendations of the Soil Report and asdirected by the Purchaser.

For underground road crossings, pipes shall be laid through R.C.C. BoxCulverts, NP-3 Hume pipes as required.

Lean concrete of the preparation of 1:4:8 may be used in lieu of back fillto support the pipe where access is limited and might result in impropercompaction of the fill. A minimum arc of contact of 120 shall bemaintained when lean concrete support is used.

4.02.03 Electrical Conduits

Electrical cable runs and supporting structures for overhead cable runsshall be designed by the bidder. Underground cable runs may be installedin trenches or on fill as may be decided by the bidder. When installed intrenches, suitable supports for the cables and the drainage arrangementof the trenches along with the design of the trench shall be theresponsibility of the bidder. To suit site condition cable trench / cablebridge shall be provided. For underground road crossing R.C.C. BoxCulverts shall be provided. For overhead road crossing minimum 8Mclearance between the bottom most member of the cable bridge and crestof the road shall be maintained. Cable trenches shall be of RCC type withminimum thickness of 150mm.

4.03.00 Requirements During Construction

4.03.01 Temporary Building

Temporary buildings shall be provided for Purchasers site office, CivilContractors site office, Cement godown, Open shed for storing

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machinery and materials and stores for storing TG material and othersophisticated materials and for labour hutments including sanitary andother facilities. The sizes and locations of the buildings shall be proposedby the civil contractor and approved by the Purchaser. Based on designloads and soil properties, bidder shall design foundations and foundationsshall be placed on virgin soil. Floor slabs, when used, shall be placed ona sand bed and shall be isolated from the foundation walls.

Super-structure requirements shall be as established by the bidder andduly approved by the Purchaser.

4.03.02 Temporary Storage Areas

Civil Contractor shall indicate area requirement and surfacing to be donefor temporary Storage areas and same will be approved by Purchaser.Storage areas shall be level and accessible by road. Grade elevationshall be such as to prevent inundation by flood water. Design andDrawings for the purpose shall be provided by bidder.

4.03.03 Temporary Working area

Temporary work area shall be provided for construction personnel andconstruction machinery. The parking area shall consist of a compactedlayer of 150 mm brick bats crushed stone or gravel with the surfacesealed with asphalt. However, to suit condition and layout of plot plan,temporary parking facility may be provided at the permanent locations.Design and Drawings for the purpose shall be provided by bidder.

5.00.00 TYPE OF CONSTRUCTION

5.01.00 Air Cooled Condenser Super structure

The A-frame assemblies in modular construction shall be mounted on theACC foundation supported on solid or hollow columns (circular/rectangular) which will be selected by the contractor depending uponheight of the column calculated as per the mechanical considerations .

The super structure of Air cooled condenser is envisaged as RCC framedstructure having two structural staircases

It may be noted that the foundation system of this ACC is being providedby purchaser.

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Fan deck shall be in structural steel system to be designed and constructedby bidder.

5.02.00 Foundation

Foundation shall be provided by purchaser to the contractor.

6.00.00 TECHNICAL SPECIFICATIONS

The description of some of the major structures/components for the ACC isgiven below :

a) Platforms and Walkways

Platforms shall be provided to all major equipment, which are not directlyaccessible from the floors, for maintenance. Platforms and connectingwalkways shall have a minimum width of 750 mm. Platforms in front of theentry shall be at least 900 mm wide. Platforms located close to each othershall be connected with walkways .

All steel platforms above grade level shall be constructed with kick plates atedge of the platform to prevent tools or materials from falling off. It shallconsist of 8 mm thick steel plate projecting 100 mm above the platformsurface. Kick plate shall be painted with the same type of coating as thematerial to which it is attached.

Continuous walkway, at least 500 mm wide shall be provided along thecrane girder level with handrails on both sides of the building. Approach toEOT crane shall be ensured by Cage ladder or staircase.

b) Stairs and Ladders

Steel Stairs

All steel staircases shall normally have minimum clear width (back to backof stringer) of 1000 mm and maximum inclination with horizontal of 35.750.However, in case of space restriction, minimum clear width upto 750 mmand slope upto 450 may be provided. The vertical height betweensuccessive landings shall not exceed 5 m. Channels (minimum MC200)shall be provided as stair stringers. Treads shall be minimum 250 mm wideof chequered plate/grating, with suitable nosing, and spaced equally so asto restrict the rise to maximum 180 mm.

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Steel Ladders

Ladders shall be provided to platforms, walkways, instruments andequipments which do not require frequent access. Ladders shall preferablybe vertical and its angle with vertical shall not exceed 50. Ladders shall beof minimum 450 mm clear width with 20 mm diameter MS rungs spaced at300 mm (maximum). Ladders shall be provided with a safety cage ofminimum 750 diameter clear when the top of ladder is more than 4.5 mabove the landing level. However safety cages shall start at 2.5 m abovethe lower landing level.

RCC Stairs

All stairs shall have maximum riser of 180 mm and a minimum tread of 250mm. However, for Administration & Control room building riser shall belimited to 150 mm and tread width of 300 mm. Minimum width of stairs shallbe 1200 mm generally. All stairs normally shall have not more than 15risers in one flight. Aluminium angle nosing with minimum 50X25X3 angleor PVC nosing shall be provided for edge protection of RCC stairs.

Handrails

Handrails shall be provided at appropriate places to ensure safetye.g. around all floors/roof openings, projections / balconies,walkways, platforms, steel stairs etc.

All handrails shall be of 32 mm nominal bore MS pipes (mediumclass) as per IS: 1161 galvanised using 750 gm/sq. m of zinc.Handrails for platforms, walkways and projections shall be a two-railsystem with the top rail 1000 mm above the walkway surface andthe intermediate rail 450 mm below the top rail. Handrail postspacing shall be limited to 1500 mm as far as possible but can beproportioned to the length of the protected horizontal opening. Insuch a case spacing shall not exceed 1850 mm center to center ofposts. Handrails shall be shop fabricated for specific locations andfield welded or bolted to the erected structural steel. For platformsat elevation more than 30 m, three rail system with top rail at 1500mm shall be adopted.

For RCC stairs, handrails with 20 mm square MS bar balustradewith suitable MS flat & aluminium / Teakwood handrail shall beprovided, unless specifically mentioned otherwise .

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Edge Protection

Wherever possible around floor openings an RCC kerb of 100 mm wide150 mm high shall be provided. All concrete edges, where breakage ofconcrete corner is expected, shall be provided with angles at least L50x50x6 with lugs for edge protection e.g. all round the cutouts/ openingsin floor slab, edges of drains supporting grating covers, edges of RCCcable/pipe trenches supporting covers, edges of manholes supportingcovers and supporting edges of precast covers etc.

Anchor Bolts and Insert Plates

Anchor bolts shall be designed for working stress, in tension and shear, forembedded length of the anchor bolts and pipe sleeves. Shear and crushingstrength of concrete shall also be checked.

Insert plates shall be designed/checked for shear and bending moment. Alllugs shall be checked for tension. Bond strength of concrete shall also bechecked. Lugs using steel bars shall preferably be fillet welded to the plateto transfer full strength of the lug.

Vertical Headroom

All accessible areas shall be provided with a minimum clear headroom asfollows, unless otherwise specified :

Finished floors to ceiling (buildings) : 3000 mmDoors, Walkways, Platforms, Stairs etc. : 2100 mmFalse ceiling of office areas : 2400 mmWalkway above false ceiling : 1000 mmSafety cage for ladders : 2500 mmAccess for forklift trucks : 2800 mmMain roads/Railway crossings & crane access : 7000 mmOther plant roads and truck access : 6000 mmCable & Pipe rack : 3000 mm(except Road/Rail crossings)

Expansion / Construction Joints

Expansion and construction joints shall be provided wherever required. Allexpansion and construction joints of water retaining structures in RCC shallbe made watertight using PVC ribbed water stops with central bulb.However, kicker type (externally placed) PVC water stops may be used forthe base slabs and in other areas where it is required to facilitate

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concreting. The minimum thickness of PVC water stops shall be 6 mm andminimum width 225 mm. At other joints these shall be 150 mm wide.

Two part polysulphide sealant conforming to IS:12118 shall be used forsealing of joints in contact with water. For other cases, bitumen sealingcompound conforming to IS:1834 shall be used. Preformed bitumenimpregnated fibre board conforming to IS:1838 shall be used as joint filler.

Statutory Requirements

All the applicable statutory rules pertaining to Indian Factories act, Factoryrules of state government, Fire safety rules of Tariff Advisory Committee,Water act of Pollution Control Boards, Explosives act etc. and stipulations,approval of other relevant statutory authorities shall be taken intoconsideration at the time of design .

Provisions of safety, health and welfare according to Factories act shall becomplied with design stage. These shall include provision of continuouswalkway (minimum 500 mm wide) along crane-girder at crane girder levelon both sides of the building, comfortable approach to EOT crane cabin,railings, fire escape, locker room for workmen, pantry, toilets, rest room etc.

Adequate number of fire escapes shall be provided in a building. Fireproofdoors, number of staircases, fire separation walls, lath plastering onstructural steel member (in fire prone areas) shall be made according to therecommendation of TAC. For fire safety requirements of buildings IS: 1641and IS: 1642 shall be followed in addition to TAC requirements. Allmasonry firewalls shall be minimum 350 mm thick and RCC firewall shallbe minimum 200 mm thick .

7.00.00 WORKMANSHIP

Workmanship shall be of the best possible quality and all work shall becarried out by skilled workmen except for those which normally requireunskilled persons. Welding shall be done by experienced and certifiedwelders in proper sequence using necessary jigs and fixtures. Fabricationshall be done in shops having proper equipment for accurate edgeplanning and milling of column shaft ends, base plate surfaces etc., andshaping and dimensioning of anchor bolt assembly, inserts and other misc.items. In addition to the requirement specified above, if the bye-laws of thelocal Govt., Municipal or other authorities require the employment oflicensed or registered workmen for various trades, the Contractor shallarrange to have the work done by such registered or licensed personnel.In case of manufactured materials, the Contractor shall have, with noadditional cost to the Purchaser, the services of the supervisors of the

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manufacturers to ensure that the work is being done according to themanufacturer's specifications.

8.00.00 TEMPORARY WORK

All scaffoldings, staging, temporary bracing and other necessary temporarywork required for proper execution of the Contract shall be provided by theContractor at his own cost and inclusive of all materials, labour, supervisionand other facilities.

The layout and details of such Temporary work shall have the priorapproval of the Purchaser, but the Contractor shall be responsible forproper strength and safety of the same. All Temporary work shall be soconstructed as not to interfere with any permanent work or with the work byany other agency. If it is necessary to remove any of the temporary work atany time to facilitate execution of the work such removal and re-erection, ifrequired, shall be carried out by the Contractor without any delay and anyextra cost on this account shall be borne by the Contractor.

9.00.00 DOCUMENT SUBMISSION

Design and Construction documents pertaining to all Civil, Structural andArchitectural works that will be required to be submitted to Purchaser/Purchaser's Consultant for their review/approval have been brought outunder following clauses. Approval of these documents by thePurchaser/Consultant shall not relieve the contractor of his responsibility forany design/construction error, mistakes and fulfillment of contractrequirements. All drawings shall be of standard sizes & in metric systemand shall be made in Auto cad (Latest). All documents shall be prepared inMS Office/PDF, as applicable. Weekly/Daily/Monthly progress/ qualityreports shall be submitted by contractor to the Purchaser as per themutually agreed format or the format which shall be recommended by thePurchaser.

9.01.00 Design Document

Design Document shall comprise Mechanical/Electrical assignmentDrawings, design data, design assumptions & references, detailedstructural analysis (including computer input and output, if any) & designcalculations and design drawings for all buildings / structures &miscellaneous services/facilities including plumbing, drainage etc. Thedrawings shall also include general plot plan, Layout plan/elevations/cross-sections/perspective view in colour, finish schedule etc. Various plans,

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perspectives and elevations shall be submitted detailing the finishtreatment.

Selected design calculations and drawings as decided by the Purchasershall be submitted and reviewed only after approval of correspondingMechanical/Electrical/System general arrangement drawings. The biddershall submit approved GA drawings along with three (3) copies of designdocuments (except design drawings), four (4) copies of design drawings forcomments/approval of the Purchaser/Consultants. Comments, if any, shallbe duly taken care of by the bidder and revised design calculations &drawings shall be resubmitted, whenever so instructed byPurchaser/Consultants, for further comments/approval. On the finalapproval of the drawing and design, bidder shall submit six (6) copies of thedrawing with one reproducible transparency (RTP) and four (4) copies offinal design calculations to Consultant for distribution. Generally review ofthe documents/drawings will be made by the Purchaser/Consultants by 21days from the date of submission of the dwgs/docs by the bidder to thePurchaser/Consultants. However the bidder should give schedulementioning the dates for submission of misc. dwgs/docs toPurchaser/Consultants for prior approval.

9.02.00 Construction Document

Based on final design drawings, detailed drawings for construction will beprepared by the Bidder. For reinforced concrete structures and foundationsdetailed bar bending schedules in approved format shall accompany eachdetailed drawing. For structural steel work detailed fabrication drawingalong with bill of materials will be prepared by the civil contractor.

Six (6) copies each of selected detailed drawings/ fabrication drawings asdecided by Purchaser shall be furnished to Purchaser/Consultants for theirreview.

Procedures for submission and approval of Construction Documents otherthan stated above shall include design of temporary works like sheet pilingfor deep excavation works, and any other item stated elsewhere in thisspecification.

The contractor shall submit six (6) copies of the final drawings along withone RTP to Purchaser/Consultants.

`As built' drawings shall be prepared by the bidder after completion ofconstruction/erection incorporating necessary changes, if any done duringexecution. The contractor shall submit two (2) copies and one RTP of the`As- built' drawings to Purchaser/Consultants.

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All documents/drawings shall be submitted in CDs/Soft Copies toPurchaser and Consultant.

The finishing items shall be indicated up to painting, flooring, etc. Biddershall provide similar details for all buildings in scope.

10.00.00 SEQUENCE OF WORK AND PROGRESS REPORT

The sequence in which the works are to be carried out shall be prepared bybidder in accordance with the construction method accepted by theEngineer-in-Charge and to be followed by the civil Contractor. Aprogramme of work is to be submitted for the Engineer-in-Charge's reviewand approval and this has to be periodically updated and modified as peractual progress to enable timely completion.

The bidder shall regularly submit to the Engineer-in-Charge progressreports for periods of working as specified by the Engineer-in-Chargeshowing upto date progress on all important items of work. L1 and L2schedule for all works is to be submitted by the bidder.

11.00.00 MISCELLANEOUS

a) The successful bidder shall take/provide/comply with but not limitedto the following:

b) Statutory Clearances from all applicable Authorities & the certificatesto be submitted to the Purchaser.

c) Copies of all studies, reports and investigations to be submitted tothe Purchaser.

d) Construction Methodology to be submitted to the Purchaser.

e) All Statutory regulations/Factory Act/Water Act/Pollution ControlNorms/ Explosive Act/Rules of TAC/Any other state or central govt.rules, regulations as applicable to be complied with.

f) Quality Assurance Plan (QAP) is to be submitted for the wholeproject work.

g) Supervision of Quality of work at site with proper testing, inspectionetc.

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h) Design Basis Report (DBR) for the full civil, structural &architectural work to be submitted to Purchaser/Consultant forapproval.

i) Supervision of all site construction work by civil contractor as perspecification, drawings, schedule.

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SPECIFIC DESIGN REQUIREMENT

1.00.00 LOADS AND LOAD COMBINATIONS

1.01.00 General

All structures shall be designed for the most critical combinations of deadloads, imposed loads, equipment loads, crane loads, steam piping (static &dynamic) and other piping loads, wind loads, seismic loads, temperatureloads, loads and forces developed due to differential settlement and anyother loading conditions which can occur during the design life of thefacility.

1.02.00 Dead Loads

Dead loads consist of the weights of the structure complete with finishes,Dead loads consist of the weights of the structure complete with finishes,fixtures, partitions, wall panels and all equipment of semi-permanent natureincluding tanks, silos, bins, partitions, roofing, piping, cable trays, bus ductsetc. The content of tanks, silo, bins and hoppers etc., shall be measured atfull capacity for this purpose.

The piping loads, cable tray loads and the contents of the tank, silos, binsand hoppers shall be listed separately so that they can be excluded fromdead load when dead loads are acting as stabilizing load for uplift.

The following unit weight of material shall be considered for computation ofloads. Loads given in IS:875 (part-I) shall be made use of for material notlisted below.

Materials : Unit weightPlan cement concrete : 2.40 t/cumReinforced cement concrete : 2.50 t/cumStructural steel : 7.85 t/cumBrick work : 2.0 t/cumCement plaster : 2.1 t/cumRoof Treatment (7 course bituminous) : 0.03 t/cumFloor Finish : 2.4 t/cumCoal : 1.20 t/cumFly Ash : 1.60 t/cumBottom Ash : 1.60 t/cum

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1.03.00 Imposed Loads

Imposed loads in different areas shall include live loads, dust loads, minorequipment loads, cable trays, small pipe racks / hanger, erection loads,operation / maintenance loads, etc. The loads considered shall not be lessthan that specified in IS:875 (part II). The loads listed here under are theminimum loads for the areas involved. Special use areas shall beinvestigated and loads revised upward as necessary. Floors andsupporting members which may be subjected to heavy equipment liveloads shall be designed on the basis of the weight of equipment orspecifically defined live loads, whichever is greater.

The specific minimum floor live loads are listed below:

Roofs

(a) Flat Roof : 1.5 kN/sqm for accessible roofs: 0.75 kN/sqm for non-accessible Roofs.

: 5.0 kN/sqm for accessible roofswith HVAC Equipment etc.

( b) Sloped Roof : As per IS: 875

Other Areas

(a) RCC floors : 5 kN/sqm for offices, laboratories,conference rooms and general floors.

(b) Stairs and balconies : 5 kN/sqm(c) Chequered plate/ gratings : 5 kN/sqm(d) Walkways : 3 kN/sqm(e) Toilet rooms : 2 kN/sqm

Piping anchor and restraint forces of major piping shall beobtained from piping analysis results and be considered as liveload in the structure design.

In addition to the live loads, a minimum of 0.50 kN/sqm shall beconsidered as Hung loads for electrical, ventilation & airconditioning. A load of 1.0 kN/sqm shall be considered as Hungloads for piping unless otherwise mentioned.

Live loads reduction shall be in accordance with the provisions ofIS:875 & IS:1893 in case of seismic analysis.

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1.04.00 Wind Load

Wind load on structures shall be calculated as per provisions of IS:875(part 3). The wind shall be assumed to blow in any direction and mostunfavorable condition shall be considered for design.

The various design parameters for the project site as defined in IS 875(Part 3).

Basic Wind Speed = 39 m/s

K1 factor = 1.06

K2 factor varies with height = corresponding to Terrain Category 2

K3 factor = 1.0

In design of structures, wind force on equipments supported on frameincluding all fixtures, piping, staircase, ladders, etc., shall also beconsidered.

1.05.00 Seismic Loads

Seismic analysis shall be carried out as per the latest edition of IS:1893(Part 1 & 4). Zone II shall be considered for design.

The Structures shall be classified into four categories as per Table 5 ofIS: 1893 (Part 4)

Importance factor for each structure shall be as per Table 2 of IS: 1893(Part 4).

Method of analysis for each structure shall be decided as per clause 10.3IS: 1893 (Part 4), which depends on the seismic zone & category of thestructure.

Response Reduction factor shall be as per Table 3 of IS: 1893 (Part 4).

1.06.00 Temperature Load

Expansion and contraction due to changes of temperatures of materials ofa structure shall be considered and adequate provisions shall be made forthe effects produced (as per provision in relevant IS codes). Suitableexpansion joints shall be provided in the longitudinal direction wherevernecessary with provision of twin columns. The maximum distance of the

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expansion joint shall be as per the provisions of IS:800 and IS:456 for steeland concrete structures respectively.

Analysis shall be carried out for ambient temperature variation. Thetemperature variation shall be considered as 2/3 of average maximumannual variation in temperature. The average maximum annual variationin temperature for this purpose shall be taken as the difference betweenthe mean of the daily minimum temperature during the coldest month ofthe year and mean of daily maximum temperature during the hottestmonth of the year. The structure shall be designed to withstand thermalstresses due to 50% of the temperature variation.

Coefficient of thermal expansion of steel shall be taken as per IS:800.Coefficient for thermal expansion for concrete shall be taken as perIS:456.

1.07.00 Equipment Loads

Static and dynamic loads of major equipments shall be based on themanufacturers data of the specified equipments and shall be consideredin design in addition to the live load. However, where the uniform floor liveload adequately accounts for the equipment moving weight, the weight ofsuch equipment as a dead load shall not be considered. Eg: switchgearand control room floors are usually designed for a live load that includesthe equipment weight.

All equipment, tanks and piping design loading shall include hydraulictesting loading. Weight of equipments, ducts, tanks, pipes, conduits, etc.,supported by structure shall include maximum possible loading conditionsis flooded material contents and associated impacts, test loadings,anchorages and constraint effects.

Air and gas duct loads shall include weight of insulation, ductattachments, dust accumulation loads, seismic, wind and other loadsapplicable.

1.08.00 Crane, Monorail & Elevator Loads

Crane girders and supporting columns shall be designed for vertical(including impact forces) and horizontal forces as per crane vendorsdata. All lifting beams and monorails shall have their design loadsincreased for impact factor as mentioned hereinafter.

Impact Factor

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Loads for cranes, hoists and elevators shall be taken as per IS:875. Theminimum impact factor to be used in design shall be as follow

Crane loads

(a) For vertical force, an impact factor of 25% of the maximum cranewheel load.

(b) A lateral crane surge of 10% of the weight of the trolley plus liftedload applied at the top of each rail divided in proportion to therelative lateral stiffness of the rail support system.

(c) A horizontal surge of 5% of the maximum static wheel loads of thecrane applied at the top of the rail.

Monorail loads

(a) Impact factor of 10% of lifted load of hoist for monorail andsupport design.

(b) Impact factor of 25% of the lifted load for electrical pulley andsupport design.

Elevator

(a) A 100% of the lifted load including elevator live load plus the cabweight for the elevator support beams.

(b) Pedestals supporting gravity take ups for conveyors andpedestals in elevator pits shall be designed assuming 100%impact factor.

1.09.00 Basic Load Cases

The following basic load cases shall be considered for the analysis:

(a) Dead load : D(b) Self weight of permanent equipment : EL(c) Live load on floor / walkway : L(d) Live load on roof : LR(e) Crane load with lift : CR1(f) Crane load without lift : CR2(g) Wind load : WL(h) Seismic load : SL

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(i) Load due to soil pressure : SP(j) Load due to surcharge : SCL(k) Load due to hydrostatic pressure : HP(l) Load due to temperature : TL(m) Special loads : SPL(n) Live load during earthquake : LLeq

1.10.00 Load Combinations

The individual members of the frame shall be designed for worstcombination of forces such as bending moment, axial force, shear forceand torsion. Permissible stresses for different load combinations shall betaken as per IS:875 (Part-V) and other relevant IS codes. Wind andseismic forces shall not be considered to act simultaneously.

Criticality of erection / maintenance loads shall also be checkedseparately in combination with other simultaneously occurring loads forpossible design loading.

2.00.00 MACHINE /EQUIPMENT SYSTEM

All machine / equipment foundations and structures subject to vibrationsshall be suitably proportioned so that amplitude and frequency of thefoundation / structures are within permissible limits.

All block foundations resting on soil shall be designed using the elastichalf space theory or Barkens theory. Block foundation resting on pilesshall be designed using Novaks theory or Barkens theory .The mass ofthe RCC block shall not be less than three times mass of the machineand the CG of the combined mass of foundation and equipment shouldpass through the CG of the base area with tolerance not more than 5%.Dynamic analysis shall be carried out to calculate natural frequencies inall modes including coupled modes and to calculate vibration amplitudes.Frequency and amplitude criteria as laid down by the relevant codes ormachine manufacturers shall be satisfied. Minimum reinforcement shallbe governed by IS: 2974 and IS:456.

For the foundations supporting minor equipment weighing less than oneton or if the mass of the rotating parts is less than one hundredth of themass of the foundation, no dynamic analysis is necessary. However, ifsuch minor equipment is to be supported on building structures, floors,etc. suitable vibration isolation shall be provided by means of springs,

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neoprene pads, etc. and such vibration isolation system ( VIS) shall bedesigned suitably.

Major Equipment foundation shall be supported on vibration isolationsystem or conventional RCC framed structure foundation. The vibrationisolation system shall consist of helical spring units and viscous damperssupporting the RCC inertia block which support the machine. The springunits shall conform to DIN 2089 and DIN 2096. For variable speedmachines conventional RCC framed structure foundation isrecommended.

The Vibration Isolation system supplied should be of proven make. TheContractor / their associates for the supply of this system should havedesigned spring supported machine foundations, manufactured, suppliedand installed vibration isolation systems consisting of steel helical springunits (Conforming to DIN 2096 & DIN 2089) and viscous dampers(Providing damping resistance in all three planes) for not less than 25(twenty five) machine foundations of heavy rotating machine systems,such as Turbine generators, Boiler feed pumps, ID/ PA / FD fans etc. Outof these atleast five(5) number of vibration isolation systems should havebeen installed for Turbo Generators of capacities not less than 210 MW.All the foundation systems be in successful operation (withoutreplacement) for at least 3(three) years as on the date of bid opening.

For inertia block of ACC foundation the following design considerationsshall be considered. Analysis and design shall be carried out inaccordance with relevant codes IS: 2974 Part-3 and IS: 456 and/ormanufacturers requirements. Static and Dynamic analysis shall becarried out using finite element computer program using 3D beam/shell or3D solid elements.

Natural frequencies and amplitude of vibrations of turbine generatorfoundations shall be as per relevant applicable code of practices asindicated above and/or as per manufacturers requirements. For dynamicanalysis, masses of stator and rotor shall be lumped at their respectiveCGs with rigid members. Fundamental natural frequencies in all threedirections shall be separated by at least 20% with respect to machinespeed. Forced vibration analysis shall be performed at the operatingspeed and also at frequencies corresponding to certain selected modes(natural frequencies within 0.9 to 1.1 times the operating speed) usingnormal machine unbalance loads. Amplitudes calculated shall be ensuredto be within the permissible limits as specified by the manufacturer. In theabsence of specified criteria, amplitude shall be limited to alarm limitspecified in ISO 10816-2. The exercise shall be repeated by releasing therotor mass in the axial direction at each bearing location except at thrust

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bearing. It shall be ensured that not more than 5% of the dynamic loadsare transmitted to the substructure. Necessary provisions of DIN 4024shall be adhered to while designing the substructure.

The loads to be considered for static analysis and design shall consist ofdead weight of the machine and foundation, machine power torque,Turbine exhaust box and exhaust duct to ACC loads under normaloperating condition, Equivalent static load due to machine unbalance,thermal elongation forces, forces due to partial operation of the air cooledcondenser , forces due to condensate pump failure , vacuum loads ,forces due to piping and ducts, frictional forces at machine sole plate levelfor turbine and generator, temperature distribution under operatingcondition, failure loads of turbine (blade unbalance/loss of blade/bowedrotor), failure loads of generator (short circuit loads), seismic loads due togenerator and turbine and erection loads.

The equipment foundations shall also be designed to meet themanufacturers static deflection criteria.

For framed type foundations which support any major rotary equipment,the criteria specified in paragraph for STG foundation shall be followed.

For design of inertia block of fan foundations, mill foundations, samecriteria as specified above shall be followed except that the analysis canbe based either on a plate model/Three dimensional solid finite elementmodel. The frequency and amplitudes shall be checked as per codal /manufacturer requirements. The permissible amplitude of vibration shallbe as specified by the manufacturer and shall be in satisfactory range asper VDI 2056, whichever is stringent. It shall be ensured that not morethan 5% of the dynamic loads are transmitted to the substructure.Necessary provisions of DIN 4024 shall be adhered to while designing thesubstructure. Substructure shall be designed for static loads.

All such foundation shall be separated from adjoining part of buildingand other foundations. Joints at floor / slab shall be suitably sealed. Allappendages to such foundations shall be reinforced suitably to ensureintegral action .

2.01.00 Increase in Stresses

Where stresses due to wind (or seismic) and temperature are combinedwith those due to other loads, the allowable stresses in concrete andreinforcement steel shall be increased by 33.33% in case of workingstress design.

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Bearing capacity of the soil shall be allowed to increase by 25% underseismic / wind load condition except for chimney where increase inbearing capacity is not considered.

3.00.00 STABILITY OF STRUCTURES

Design shall be checked against buoyancy due to the ground waterduring construction and maintenance stages for structures like underground tanks, pits trenches, basements, etc. Minimum factor of safety of1.2 against buoyancy shall be ensured considering empty condition insideand ignoring the superimposed loading. For purpose of calculatingdownward load due to any overburden, only the mass located verticallyabove the projected area shall be taken in to consideration.

All building sub-structures including pump houses shall be checked forsliding and overturning stability during both construction and operatingconditions for various combination of loads. Factor of safety for thesecases shall be taken as mentioned in IS:456 and other relevant IS codesHowever, following minimum factor of safety shall be followed.

a) Factor of safety against overturning due to wind, seismic or otherlateral load shall be 1.5 minimum.

b) Factor of safety against sliding shall be 1.5 minimum.

c) Factor of safety against uplift due to hydrostatic forces shall be 1.2and due to any other loads shall be 1.5.

Stability of the structure shall also be investigated for loading conditionsduring construction, repair or other temporary measures. Lower factor ofsafety may be used for such loading conditions as per relevant IS codes.

In case where dead load provides the restoring force, only 0.9 timescharacteristic dead load shall be considered. Imposed loads shall not beconsidered as restoring force.

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4.00.00 REINFORCED CONCRETE STRUCTURES AND FOUNDATIONS

All structures, building foundations, machines / equipments foundation,water retaining structure, trenches, pits, etc., shall be designed as perrelevant IS codes in general. Construction in general shall followprovisions of IS:456 and IS:3370 for normal and water retaining structuresrespectively.

4.01.00 Design Methodology

General

All designs of RCC structures shall be carried out by limit state methodas per IS:456 unless use of working stress method is specificallymentioned. Design strength of materials and design loads shall becalculated using appropriate partial safety factors over characteristicstrength and characteristic loads as per IS:456.

For reinforcement detailing IS:5525 and SP:34 shall be followed.

4.02.00 Minimum Thickness Of Structural Elements

The following minimum thickness shall be followed :

(a) Suspended floor / slab / walkways / canopy slabs, etc 125 mm

(b) Ground floor slab (non-suspended) 150 mm

(c) Water Retaining slabs / walls 200 mm

(d) Cable / pipe trenches / underground pits / Launderwalls and base slab 125 mm

(e) All footings (including raft foundations) 300 mm

(f) Parapets 125 mm

(g) Sunshades 75mm at stage

(h) Precast louvers / fins 50 mm

(i) Precast trench cover slabs / floor slabs / louvers 75 mm

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(j) Paving 100 mm

(k) Pile cap 600 mm

(l) Basement walls and base slab 200 mm

(m) Silo / bin walls 150 mm

(n) Underground reservoirBelow ground water table 200 mmAbove ground water table 150 mm

From fire resistance point of view minimum thickness of reinforcedconcrete members shall be as per fig 1 of IS 456. Minimum fire rating of 2hours shall be considered where fire hazard is expected.

4.02.00 Minimum Heights For Pedestals Of Steel Columns

Pedestals to Steel Columns for building structures :

Top or RCC foundations (pedestals) shall normally by kept at a lowerlevel so that the column base plates together with gussets and stiffeners,remain below finished floor level (FFL) unless specified otherwise.Foundation levels for some columns shall be changed suitably toaccommodate underground services, pits, trenches, etc.

Stair and ladder pedestal shall be kept 200 mm above the finished floorlevel.

Pedestals to Steel Columns for Equipment structure :

(a) Equipment in open area : as required (300mm min)

(b) Equipment in covered area : as required (150 mm min)

(c) Structures and equipment : as per vendors data subjectsupplied by vendor to minimum as specified

above.

Minimum Heights for Encasement for Steel Columns

In case the top of pedestal is kept at a lower level so that the columnbase plate together with gussets and stiffeners remain below finishedfloor level (FFL) the column bases as well as the column sections shall beencased in concrete above FFL as per following.

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(a) Open area : 300 mm above paved level(b) Covered area : 150 mm above FFL

5.00.00 Materials

Concrete Mix

The following minimum grades of concrete as per IS:456 shall generallybe used for the type of structures noted against each grade. Cement usedshall be ordinary Portland cement (OPC) of 43 Grade conforming to IS8113, unless the chemical nature of the soil warrants special cement forstructures below ground level.

Mix (1:5:10) : Fill concrete.

Mix (1:4:8) : Foundation below brick wall, blinding layer belowfoundations, trenches and undergroundstructures, minimum thickness of the layer shallbe 75 mm.

Grade M20 : Base plate encasement, pavement aroundbuilding including plinth protection work,encasement of structural steel work, etc.

Grade M25 : Ground floor slabs , SG area paving etc.,

Grade M25 : All RCC members except where other grades arespecified e.g. Foundation and super structure,grade beams, pedestals, roof slabs, Cable andpipe trenches, etc.

Grade M25 : Water retaining structures below and aboveground, Cooling water channel , fore-bay & sump,cooling tower basin etc.

Intermixing of different grades of concrete in the same structure shall notbe allowed in a particular structural element.

Minimum cement content shall be governed by the requirement ofIS:456 for normal concrete structures and IS:2911 for piles.

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However higher grade of concrete shall also be used than the minimumspecified to satisfy the design requirement for TG foundations, BFPfoundations , under ground structures etc.,

The clear cover to reinforcement shall be for 2 hours fire rating as pertable 16 A of IS456 and also meet the requirement of durabilityrequirements based on exposure conditions as per table 16 , whichever isstringent.

Reinforcements

Reinforcement bars shall be as per the following codes :

High Yield Strength Deformed bars : IS:1786Mild steel bars : Grade I of IS:432Welded wire fabric : IS:1566

Intermixing of different grades of re-bars or re-bars of different materialcomposition in same structure shall not be allowed.

Contractor shall supply to the Purchaser copies of all manufacturerstest certificates for reinforcement bar delivered to site. The certificate shallshow the results of tests necessary to prove that the reinforcementcomplies in respects with the relevant Indian Standards.

Bars shall not be bent or straightened in a manner that will damage thebar Reinforcement shall be bent cold.

All reinforcement shall be accurately fixed by approved means andmaintained in correct position as shown in the drawings by use of blocks,spacers and chairs as per IS 2502 to prevent displacement during placingand compaction of concrete.

No metal part of any device shall be used for connecting bars or formaintaining reinforcement in the correct position with in the specifiedminimum concrete cover to the reinforcement.

Welding of reinforcement shall not be carried out without the permissionof the Purchaser.

Projecting reinforcement or dowel bars for future connection of thestructural works shall be protected by lean cement concrete, if they are tobe left exposed for a long time.

Reinforcement detailing shall be as per IS 456,SP 34.

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In watertight construction, methods of fixing formwork, which result inholes through the concrete section when the formwork is removed, shallnot be used. All wall ties shall have water baffles and wall kickers shall becast monolithically with the base slab.

Approval for the size, type and position of any holes, insert or fixingrequired by CONTRACTOR shall be obtained before work proceeds.Unless otherwise specified or approved all holes shall be formed and allinserts cast in at the time of pouring and no part of the concrete worksshall be drilled or cut away without approval.

Formwork panels shall be stiff enough to prevent damage to theconcrete surface caused by excessive movements of the panel duringvibration of the concrete.

Damaged and used formwork shall not be re used without repairing.

All joints in form work and joints between the form works shall besufficiently tight to prevent loss of liquid from the concrete through these

joints.

The part of the ties shall be capable of being removed, so that no partremaining embedded in the concrete shall be nearer the surface of theconcrete than the specified thickness of cover to the reinforcement. Holesleft after the removal of ties shall be filled with concrete or mortar ofapproved composition.

Formwork props shall be positioned between permanent supports sothat all members are supported at not more than 3 meters centre in bothdirections.

The props shall be in the form of space frames, composite or singlemembers with sufficient stiffness or bracing so that props will neithersway nor buckle under loads which they are designed to carry.

The formwork or the false work shall not be removed from a structuralcomponent until CONTRACTOR ensure that the concrete has attainedsufficient strength.

The concrete is to be regarded as sufficiently hardened when thecomponent has attained such strength that it can resist all loads acting atthe time of removal of the formwork.

Particular care shall be taken with components which have to carryvirtually the full design load directly upon removal of the false work (e.g. in

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the case of roofs, or floor slabs which have to support loading from floorsabove them which have not yet hardened).

Props shall remain in position for as long a period a possible, particularlyfor structural components, which are subjected to a major proportion oftheir design loading as soon as the formwork has been removed.

No superimposed load shall be allowed on any part of the concrete workprior to the removal of the forms and props.

Unless specified 20mm and down graded aggregates shall be used forall structural concrete works. However 40mm and down gradedaggregates may also be used under special conditions for foundation.

Tolerance for formed and concrete dimension shall be as per IS:456.

Placing of concrete

Before each concreting, CONTRACTOR shall give sufficient notice tothe Purchaser as directed such that an inspection will be made before theconcreting.

The concrete shall be mixed in the mixer of adequate capacity having apower elevated loading hopper. The mixer shall be equipped with anautomatic water-measuring tank filled with a device for locking thedischarge setting. The Mixing shall continue until there is a uniformdistribution of the materials and the mass is uniform in colour andconsistency.

Any concrete surplus to immediate requirements shall be thrown away.In no case or circumstances may the surplus be used later. The volume of mixed materials in each batch shall comply with the mixermanufacturers written recommendations.

Concrete shall be transported as quickly as possible from the mixer toits final position without segregation or loss of any of the ingredients.

All equipment to be used for transporting material shall be kept clean; allcontainers used for transporting concrete shall be thoroughly washed outwhenever mixing ceases.

Concrete shall be placed continuously up to construction joints while it isstill sufficiently plastic for adequate compaction.

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At all times when reinforced concrete is being placed a competent steelfitter shall be in continuous attendance. CONTRACTOR shall adjust andcorrect the position of any reinforcement, which may be displaced.

CONTRACTOR shall keep on site a complete record of the worksshowing the time and date when concrete is placed in each part of thework.

Concrete shall be thoroughly compacted by suitable mechanicalvibrators during placing and shall be carefully worked around allreinforcement and embedded fixtures and in to the side and corners ofthe formwork.

For top surfaces of slab and other surfaces for which formwork is notprovided a smooth finish shall be provided with a wooden float aftercompaction.

Whenever, concrete is being vibrated at least one spare vibrator of eachtype in use shall be available in case of breakdown.

Compaction shall start as soon as there is sufficient concrete within theformwork to immerse the vibrator and vibration shall continue during theplacing operation so that at no time shall there be a large volume of uncompacted concrete in the form work.

The concrete shall not be placed directly against a vertical form face butshall be placed to flow to this surface during the compaction process.Care shall be taken to avoid the form face being splashed with mortarduring the placing operation.

Exposed surfaces, immediately after final set, shall be protected fromthe sun. All concrete shall be well watered after it has been set and shallbe kept continuously damp until thoroughly cured. Provision shall bemade for adequate water distribution to all parts of the work so that ifrequired this treatment can be continued sufficiently throughout the wholeperiod of construction. In order to keep the concrete continuously damp,all exposed surface shall be covered with continuously damped gunnybags or shall have water compounded on them, for full period of curing.

On exposed concrete surfaces in high sun temperatures and /or strongdrying wind conditions CONTRACTOR shall use curing method, whichalso shields the concrete, and this shall be placed in position not laterthan half an hour after final tamping .

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7.00.00 STEEL STRUCTURES

Framing

All steel framed structures shall be either rigid frame or simple spaceframes or a combination of two .

Lateral forces shall be resisted by stiff jointed moment connections in rigidframe design. The column bases shall generally be fixed to concretefoundation pedestal by providing moment resistant base detail.

Simple space frame design utilises single-span beam systems, verticaldiagonal bracing at main column lines and horizontal bracing at the roofand major floor levels. Most of the plant steel buildings shall be designedas simple space frame structures.

The turbine building design shall be a combination of rigid frame intransverse direction and simple frame in longitudinal direction.

Pipe rack shall consist of rigid main frame in transverse direction spacedlongitudinally as required. In longitudinal direction, pipe rack shall bedivided into sections of suitable length with an anchor bay. The maintransverse frames shall be connected with longitudinal beams which willtransmit horizontal forces to braced anchor bays. The pipe and cable rackbridge structure shall be adequately rigid to carry the forces frompipelines at anchor points without undue deflection so that pipelines arereally anchored at the anchor points.

Concrete floors shall be considered to provide continuous lateral supportto the top (compression ) flange of the support beams. However whereverlarge cut outs are provided in the floor slabs horizontal floor bracing shallbe provided. Grating/chequered plate floor shall neither be considered toprovide lateral support to the top flange of supporting beams nor toprovide a shear diaphragm. Adequate lateral support and horizontalbracing shall be provided as required.

Floors for vibrating machines of all kinds together with supportingframework shall be adequately braced in both horizontal and verticalplanes. Floors or structure supporting mechanical equipment shall bedesigned to minimise vibration, avoid resonance and maintain alignmentand level.

Columns shall be designed to support the load combination whichproduces the maximum interaction ratio. Exterior columns shall bedesigned to resist wind moments between braced elevations as

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appropriate. Columns shall also be designed to resist moments causedby discontinuous vertical bracing or non-concentric bracing work points .

7.01.00 Materials

Structural steel shall conform to Grade A of IS:2062 for rolled steelmembers or plates up to 20 mm thickness. For plates above 20 mmthickness or welded construction, steel conforming to Grade B (Killed) ofIS:2062 shall be used except for crane girders where Grade C (IS:2062)steel shall be used.

Checkered plates shall conform to IS:3502. All gratings shall bepressure locked type (preferably electro-forged) manufactured inaccordance with applicable Indian standard. Pipes for handrail shall be asper medium grade of IS:1161.Crane rails shall conform to IS:3443.

7.02.00 Connections

Welding shall be used for fabrication and joints. For site connections,welding or high strength MS bolts of property class 4.6 or 6.6 shall beused, except in few cases for shear connections of lighter members orremovable beam connections where bolted joints may be adopted e.g.purlins, side girts etc with ordinary MS black hexagonal bolts. A minimumof two bolts per connection shall be used. High strength frictiongrip(HSFG) bolts shall be used as necessary if required.

IS:816 and IS:9595 shall be followed for welding of structures.

For high strength friction grip bolt connections IS:4000 shall be followed.High strength friction grip bolts shall be of property class 6.6 or 8.8 andshall conform to IS:3757 and shall not be less than 20 mm in diameterunless designated otherwise. High strength bolts shall be installed asbearing type joint except where loads are reversible.

All bolted connections shall have bolts of minimum 16 mm dia. Theconnections of stairs and hand railing shall be made with 20 mm diameterthreaded fasteners conforming to IS:1363. Erection bolts shall be blackbolts of minimum 12 mm dia.

All bolts and nuts shall have property class compatible to each other.For bolts carrying dynamic or fluctuating loads and those in direct tensionshall be provided with an additional double coil helical spring washerconforming to IS:6755. The threaded portion of the bolt shall projectthrough the nut at least by one thread.

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Where a steel beam or member is to be connected on RCC structure, itshall be connected using an insert plate and preferably through shearconnection.

For crane girders, welding between web and flange plates shall becarried out by submerged arc welding process. Full penetration of weldbetween web plate and top flange shall be ensured. Intermediatestiffeners shall be connected with top flange plate by full penetration buttweld. Welding across tension flange will not be permitted. Bearing edgesof crane girders shall be machined.

The working point of the bracing connection shall be the center ofcolumn and girder to which it connects, where practical. The connectionsof gusset plates to column and girders shall be made to includeprovisions for eccentricity in connection. The double angle back-to-backwith gusset plate in between shall not be used in dust laden areas. Wheredouble angles are not adequate, beam sections with web in the plane ofbracing are used.

Horizontal bracings shall be angle / tee section located at the bottom offraming beams. Field welding of bracing at the underside of beam asrequired to meet slenderness requirement of bracing member shall beindicated on the drawings. Horizontal bracing shall be arranged to avoidframing into the beams at column locations.

For Major columns of main building, column splices shall be designed toresist the greater of the design axial tension load and moments or anaxial tension load of 45 t plus 50% of the member capacity in bending ineither the major or minor axis, whichever produces the greatest numberof bolts.

Minimum size of fillet weld shall be 5 mm. Main structural elements shallbe welded continuously. Intermittent weld shall be used only onsecondary members, which are not exposed to weather or other corrosiveinfluence.

Efficiency of site welds to be considered shall be as follows:

a) Butt weld above 25 m from ground : 50%

b) Others : 80%

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