Special Conditions Of Contract Part B - konkanrailway.com Conditions of Contract – Part – B Kudgi STPP, EW – Package – I, NTPC yard

Special Conditions of Contract – Part – B Kudgi STPP, EW – Package – I, NTPC yard

69 Konkan Railway Corporation Limited Signature of Tenderer

Special Conditions Of Contract

Part – B



SPECIAL CONDITIONS OF CONTRACT – PART – B

1. INTRODUCTION:

1.1 This section deals with the technical specifications of the work. The Work shall be carried to the satisfaction of the Engineer-in-charge and conform to the location, lines, dimensions and cross-sections shown in the drawings or as indicated by Engineer-in-Charge. The salient features, quality of materials and finished work shall comply with the requirements set forth in the succeeding sections. Where the drawings and specifications describe a portion of the work in only general terms, and not in complete detail, it shall be understood that only the best general practice is to prevail, materials and workmanship of the best quality are to be employed and instructions of the Engineer-in-charge are to be fully complied with. Specifications for some of the items of work are based on current specifications and recommended codes of practice.

2. SCOPE OF WORK:

a) The Earthwork in Cutting and Embankment (Filling) is to be done in NTPC In-plant yard area (work site of the present tender) when land will be made available for execution of Earthwork. The In-plant yard is having total 22 lines and to be constructed in the area with overall 400 meter width and around 4.0 km length from Chainage 3/800 to 5/400 (Package – I Earthwork) and 5/400 to 7/800 (Package – II Earthwork) Earthwork to be done in the 400 meter width x 4000 meter length area in two packages. This tender Earthwork is for Package – I between km 3/800 to 5/400 but leading of cutspoils is to be filled in Embankment in Package – II Chainage also as described subsequently. [This In-plant yard is situated as shown in the key plan (Appendix – 18)].

b) Earthwork in cutting and leading it to spoil dump or filling in to embankment in In-plant yard between KM 3/800 to 7/800 including adjoining Earthwork section / jurisdiction / Chainage (Package – II) between KM 5/400 to 7/800 as per direction of Engineer-in-charge with all lead and lift, ascent, descent, manpower, transportation, etc.

c) The NTPC / Corporation cutspoils quantity in this package is more than the filling quantity for Embankment and hence most of the cutspoils should be transported to Package – II Chainage without extra payment which is adjoining area from Chainage 5/400 to 7/800 and to be spread for Filling (Embankment) in this stretch. The rate will be paid as per Schedule – A.

d) Earthwork in embankment with contractor’s own earth up to level as directed by

Engineer-in-charge with all lead and lift, if required based on the conditions of

cutspoils.

e) Providing blanketing material as given in schedule in cutting / embankment and

as per latest RDSO Specification. The locations and thickness by layers of

blanketing will be decided by Engineer-in-Charge as per site conditions.

f) The approximate length of Embankment (filling) is 900 mtrs i.e. from Chainage

3/800 to 4/700 for single track of top width 6.85 mtrs and height up to 14.0 mtrs.

The approximate length of Cutting is 700 mtrs i.e. from Chainage 4/700 to 5/400

for 1 to 11 lines of track for cutting width 40 mtrs to 290 mtrs approximately.



g) Excavation and construction of catch water drains, Nallah diversion, filling in bridge approaches etc. if required.

h) Construction of trolley refuges in bank and cutting if required.

i) Temporary road diversion Earthworks and other related works.

j) Any other Earthwork as decided by Engineer-in-charge between KM 3/800 to

7/800 (beyond km 5/400 also) with no extra payment as payment shall be made as per Schedules / accurate rate under this contract.

k) The quantities mentioned under Schedule – ‘A’, Schedule – ‘B’ and Schedule – ‘C’ items are only indicative and shall vary on either side during execution based on strata and classification. Some quantities of items Schedule – ‘A’, Schedule – ‘B’ and Schedule – ‘C’ may decrease or increase and no claim shall be made by contractor due to increase or decrease of any items of the tender. The classification shall be decided by Engineer-in-charge (or his higher authorities) which shall be final and binding on the contractor.

l) Mechanical compaction of Embankment / blanketing materials by layers as per

specifications of latest RDSO Guidelines for Earthwork in Railway projects including latest correction slips.

m) Submission of detailed construction schedule, Detailed Method Statement

(methodology of work) with related detailed drawings and equipment planning including mobilization schedule for various items of work to complete the whole work in stipulated time frame given in tender document. Tenderer shall give PERT Chart for Earthworks at the time of submission of tender by indicating completion of works within the stipulated time.

n) Nallah diversions and their protection works.

o) Construction of catch water drains.

p) All safety arrangements as per relevant IS, IRC and IRS Codes of practice and

as specified in the tender documents.

q) Storage of explosives at work site as per site requirements by arranging contractor’s own stationary & mobile magazine, security etc.

r) Construction of all temporary diversions of roads, nallas & Canals.

s) Co-ordination with authorities concerned for shifting various existing utilities like

electric lines, water supply lines etc. and executing incidental works to facilitate this.

t) Maintenance of all works including service roads for the specified period.

u) All permanent and temporary works, which are necessary for successful

completion of all works.

v) Keeping regular record of construction activities / Daily progress register etc.

w) The information and data stated and incorporated in tender document elsewhere are for the general guidance only and may vary as a result of more detailed site investigation and construction drawings / decisions based on site conditions.



x) To survey and setting out the proposed alignment and prepare the necessary drawings / cross-sections / Longitudinal sections. Levels should be also taken regularly at desired intervals as directed by Corporation.

y) Any other incidental / ancillary works connected with construction of above works (tendered contract works) as directed by the Engineer-in-charge.

z) The work(s) specified under this contract shall include all general works, preparatory to the construction such as construction of service roads, crossing of nallahs / streams / channel / drains and all other items and requisites necessary and maintenance of works, compliance with all Konkan Railway’s Standard General Condition of Contract, January 2014, along with latest correction Slips / Special Conditions of Contract Part – A & Part – B whether specifically mentioned or not, all materials, apparatus, plants, machinery, tools, fuel, water, power supply, strutting, and tackling problems of every description, transport, offices, stores, workshop, staff, labour and the provision of proper and sufficient protection works, diversion, temporary fencing, lighting and watching required for safety of the public and protection of the works and adjoining land, first aid equipment, sanitary, accommodation of the staff and workmen, the effecting and maintenance of all insurances, the payment of all wages, salaries, fees, royalties, duties or the other charges arising out of the erection of works and regular clearance of rubbish, clearing up and leaving site clean on completion. The cost of such items shall be deemed to have been included in the rates given in the Schedule for various items and percentage rate quoted by contractor and nothing

extra is payable.

aa) Preparation of completion drawings (all detailed drawings / cross-sections) on

polyester based Reproducible tracing films made out of AUTOCAD package. (No extra payment for the same). The contractor should submit 3 sets of hard copies of completion drawings as finalised. Soft copy in the relevant format to be also given.

3. DRAWINGS:

3.1 The typical Cross-sections for Cutting and Filling (Embankment) / drawings are given in the

Appendix – 16 & Appendix – 17 of the tender document. The construction shall be as per Corporation’s approved drawings / cross-sections. The drawings attached are for guidance only and Corporation may modify the drawings to suit site conditions and contractor shall have no claim on this account.

4. CODES AND SPECIFICATIONS:

(i) INDIAN RAILWAY STANDARD MAJOR CODES AND SPECIFICATIONS (Latest

version with correction slips upto date)

1. Indian Railways Schedule of dimensions for Broad Gauge.

2. Indian Railways Permanent Way Manual.

3. Indian Railways Works Manual.

4. Latest Guidelines for Earthwork in Railway Projects, Guideline No. G.E: G-1, July 2003 (including correction slips of Research Designs & Standards Organisation (RDSO).



5. Latest Guidelines for Blanket layer Provision on track formation with Emphasis on

heavy Axle load train operation (including correction slips of Research Designs &

Standards Organisation (RDSO) (Report No. RDSO /2007/GE: 0011 July 2007).

6. Indian Railway Bridge Manual, if applicable.

7. Any other applicable manual / circulars as per Indian Railway / RDSO.

(ii) INDIAN STANDARDS CODES & SPECIFICATIONS

1. IS: 1270 – Metric steel tape measure.

2. IS: 1498 – 1970 Classification and Identification of Soils.

3. IS: 2131 – Standard penetration test for soils.

4. IS: 2132 – Thin walled tube sampling of soils.

5. IS: 2720 (all 41 parts) – Method of tests for soils.

6. IS: 3764 – Safety code for excavation work.

7. IS: 4081 – Safety code for blasting and related drilling operations.

8. IS: 7293 – Safety code for working with construction machinery.

9. Indian Explosive Act – 1988.

10. Indian Explosive Rules – 1983.

NOTE:

a. Latest edition including correction slips issued from time to time upto the time shall govern.

b. The list given above is indicative and not exhaustive. All IRS, IRC, IS codes and RDSO latest guidelines pertaining to the work shall be applicable.

c. Where the drawings and specifications describe a portion of the work in only general terms and not in complete details, it shall be understood that only the best general practice is to prevail, materials and workmanship of the best quality are to be employed & the instructions of the Engineer are to be complied with.

d. Omissions, errors if any shall be exempted.

4.1 The specifications mentioned in Technical Specifications for Earthwork shall be prime governing.

4.2 Where there is conflict between IRS & IS Specifications, IRS specifications shall prevail.

4.3 Where there is no provision of specifications in IRS, the IRC conditions shall be followed.

4.4 Apart from the basic data, specifications etc. all items of works shall be governed by the codes

given in Clause No 4.0 above, as revised / corrected / amended from time to time.

4.5 KRCL reserves the right to reject or alter any part of the work executed by the Contractor, which in

the judgment of KRCL does not comply with the requirements of the above specifications. The decision of KRCL shall be final and conclusive for all-purpose and contractor shall have no claim on this account whatsoever.



5. Survey and Setting out works

5.1 Immediately after award of the work, the contractor shall engage his engineers / surveyors and other manpower, equipment etc. to survey the proposed alignment.

5.2 Contractor shall be responsible for correct setting out of all works in terms of Clause no. 19 (4) of Konkan Railway’s Standard General Condition of Contract, January 2014, along with latest correction slips.

6. EXCAVATION FOR YARD IN CUTTING AND FILLING (EMBANKMENT)

6.1 SPECIFICATIONS FOR EARTHWORK AND BLANKETING

Latest RDSO Guidelines for Earthwork in Railway projects Guideline no. GE:G-1 (including

correction slips) July 2003 and Blanket layer Provision on track formation with Emphasis on

heavy Axle load train operation (including correction slips of Research Designs & Standards

Organisation (RDSO) (Report No. RDSO /2007/GE:0011 July 2007) are to be followed.

6.1.1 Formation works:-

(i) Earthwork in Embankments with Railway’s earth.

(ii) Earthwork in Embankments with Contractor’s earth.

(iii) Earthwork in Cuttings in Soil.

(iv) Earthwork in Cuttings in Rock not requiring blasting (soft rock).

(v) Earthwork in Cuttings in Rock requiring blasting.

(vi) Supplying and Spreading Blanketing material.

(vii) Mechanical compaction of Filling / Blanketing materials.

6.1.2 The above items of work envisage earthwork in Railway Formations and other works

incidental thereto including earthwork in level crossing, road approaches, trolley refuges,

Bridge approaches, man refuges, side drains catch water drains, nallah diversions, road

diversions and all other earthwork items incidental to the Railway Formation works as

directed by the Engineer-in-charge whose decision in this regard being final and

conclusive.

6.1.3 Without in anyway restricting or modifying the provisions of the Konkan Railway’s

Standard General Condition of Contract, January 2014, along with latest correction

Slips. In this regard, the rates for the above works shall be also inclusive of all

costs of the following elements.

6.1.4 Excavations in borrow pits, cuttings in all types of soils, soft rocks & hard rocks etc. as

applicable and in all conditions. Whether dry, moist, wet or slushy inclusive of pumping

out of water as may be required for the execution of work etc. complete with all

contractor’s labour, materials, explosives, other consumable materials, tools, plants and

machinery, fuel crew etc.



6.1.5 All leads; all crossings of Railway lines, road and nallahs as required; all lifts & all

descents etc. required for forming the embankments or disposing the excavated

materials from the cuttings by stacking or in any other manner, in embankment, spoil

dumps, stacks or any other location as directed by the Engineer-in-charge whose

decision in this regard being final and conclusive; providing earth bunds for stagnating

water on embankments and dressing up of all slopes, surfaces etc. complete with all

contractor labour, material, tools, plants and machinery including fuel, crew etc.

6.1.6 Spreading the earth or the excavated materials from cuttings or blanketing material in

layers of specified thickness adding water as required, compaction with contractor’s

approved type of compacting / rolling equipment etc. complete with all contractor’s

labour, materials, tools, plants and machinery, fuel, crew etc.

6.1.7 For earthwork in embankments with Contractor’s earth and supplying and spreading of

blanketing material in addition to the above, the rates will be inclusive of the cost of

acquisition of the earth or blanketing material, by purchase of land or payment of royalty

charges or in any other manner, transportation with all lead and lift and all other

incidental works, complete, for bringing the earth or blanketing material from outside the

NTPC land.

6.1.8 The payment for the earthwork and supplying and spreading of blanketing

material will be made on the basis of cross sections for the compacted work as

accepted by the Engineer-in-charge. No extra payment will be made for blanketing

material and it will be paid in contractor’s own earth item.

6.1.9 The earthwork with Railway’s soil (NTPC cutspoils) shall be executed only from the

borrow areas specified by the Engineer for this purpose. The earthwork with

Contractor’s soil and supplying and spreading of the blanketing material shall be

executed from the Contractor’s own borrow areas after approval by the Engineer, whose

decision in this regard shall be final and conclusive.

6.1.10 For the purpose of determining the suitability of the soil, the blanketing material and the

measures to be adopted for the field quality control, the contractor shall extract

adequate number of samples of the soil / blanketing material from the nominated borrow

areas and cuttings as directed by the Engineer-in-charge from time to time. The samples

shall be extracted in manner specified in the relevant Indian Standard Specifications

(ISS) or the Indian Standard Code of practice (ISC).

6.1.11 The soil / blanketing material samples mentioned herein above shall be tested as

prescribed in the relevant ISC or ISS to determine.

i) The suitability of the soil and the blanketing material for the work.

ii) The natural dry density of soil in the top 300 mm of the formation in the cuttings.

iii) For the soil to be used in the embankments and as obtained in the top surface of

the cuttings finished to final level, the Maximum Dry Density (MDD) & the Optimum

Moisture Content OMC) shall be obtained from Heavy Compaction in accordance

with IS-2720 (part VIII).



iv) For the blanketing material, the MDD and OMC as obtained from Heavy

Compaction in accordance with IS-2720 (Part VIII).

v) Suitable type of Rolling / Compaction equipment.

vi) The measures to be adopted for Field quality control of compaction.

vii) Any other parameter of the material characteristics as considered necessary by the

Engineer-in-charge for the proper execution of the work.

6.1.12 The decision of the Engineer-in-charge on the number of samples, their locations, the

frequency of the extractions, soil / blanketing material characterization / field control

measures to be determined from the testing of the samples, the acceptance and

application of the test results to decide if the soil / blanketing material is suitable for the

work and determine the quality control measures for the execution of the work etc. shall

be final and conclusive.

6.1.13 The expenditure on extraction and testing of soil / blanketing material samples (when

done through an outside agency, other than Corporation, as decided by the Engineer

whose decision in this regard being final and conclusive) as mentioned herein above

shall be borne by the Contractor and is deemed to have been included in the contracted

rates for the work.

6.1.14 Before commencing the work and during the progress of the work as and when

considered necessary by the Engineer-in-charge, the method for field control of

moisture and compaction will be determined by the Engineer-in-charge adopting any of

the methods specified in IS-10379. All the tests required to be performed for this

purpose to determine the field quality control system shall be carried out by the

contractor as specified herein above with contractor’s equipment’s.

6.1.15 For earthwork in embankments, after site clearance all pockets and depressions left in

the soil, if any shall be made good and compacted.

6.1.16 The blanketing work shall cover the entire width of the embankment and / or cutting from

shoulder to shoulder. If the material is erodible, it shall be confined in a trench with

berms of width as specified by the Engineer-in-charge. In such cases adequate sand

drains as directed by the Engineer-in-charge shall be provided across the cess.

6.1.17 The earthwork in embankments / spreading of the blanketing materials shall be done in

layers not exceeding 600 mm thick where vibratory rollers are used, or 300 mm thick in

other cases or the optimum thickness as determined after carrying out the specified field

test as applicable, the thickness of the layers being reckoned in the loose state. Where

the compaction is done with sheep-foot rollers, the depth of each layer of loose soil /

blanketing material shall not exceed by more than 10 mm the length of their feet. The

type of the rolling / compaction equipment to be used in the work, the number of passes

required of the rolling / compacting equipment etc. shall be as directed by the Engineer-

in-charge whose decision in this regard shall be final and conclusive.



6.1.18 The earthwork in embankments, the formation level surface of cutting and the blanketing

work shall be compacted as directed by the Engineer whose decision in this regard shall

be final and conclusive. The compaction should preferably be done at the OMC.

Depending on site conditions, the Engineer, at his sole discretion may permit the

variation in the moisture content at the compaction stage of say (-) 2% with respect to

the OMC subject to the acceptance criteria for the field compacted density. The

compaction at a moisture content higher than the OMC may be permitted by the

Engineer at his sole discretion subject to the moisture content being less than the plastic

limit for the type of material being used in the embankment / blanketing layers.

6.1.19 Where the soil / blanketing material is dry, water shall be sprinkled either in the borrow

pit or over the spread layers, as convenient, in order to attain a workable moisture

content before rolling / compaction is commenced. Where the natural moisture of the

soil / blanketing material in any layer is higher than OMC, soil / blanketing material may

be left for drying for a suitable period till the moisture content is reduced to the OMC

level or the rolling / compaction commenced under specific permission of the Engineer-

in-charge as provided herein above.

6.1.20 The acceptance criteria for the compaction work shall be as under:-

a) Coarse grained or cohesion less soil / blanketing material which may contain fines

passing 75 microns IS sieve up to 5% for plastic fines and up to 12% for non-

plastic fines shall be compacted so as to obtain a minimum Density Index

(Relative density of 70% as obtained in accordance with the I.S. 2720 (Part XIV).

b) All other types of soils used in the embankments and all types of blanketing

materials other than coarse grained blanketing material as specified herein above

shall be compacted so as to obtain 98% of the MDD as determined using heavy

compaction in accordance with I.S. 2720 (Part VIII) 1983, the actual percentage of

the MDD to be obtained within the above range shall be determined by the

Engineer based on the field trials carried out in the manner specified herein above.

7. PROVISION OF BLANKETING LAYER:

7.1 The thickness of the blanketing materials from where it starts will be decided by the

Engineer-in-charge at the time of execution. The blanketing layer will have to be

compacted. The total compacted thickness of the blanketing layer will be decided by

Engineer-in-charge depending upon the properties of the formation soil. Thickness of

the blanketing layer will be specified by the Engineer in writing before commencement of

this work. The Contractor will have no claim due to reduced / increased quantities on

account of the change of thickness of blanketing layer. Blanketing layer shall be laid in

layers not exceeding 300 mm. in thickness in loose state and compacted at or near

Optimum Moisture Content with suitable compacting machinery so as to obtain in the

field dry density not less than 98% of the Maximum Dry Density as determined by using

Heavy Compaction Test in accordance with Indian Standards Specification No. IS 2720

(Pt.VIII) 1983. The number of passes of compacting machinery and optimum thickness

of each layer will be fixed after carrying out field trials from time to time and from location

to location.



7.2 The contractor shall get the written approval of the Engineer of the site from where he /

she proposes to bring the blanketing material and the proportion of moorum and sand

considered necessary before transporting the same to the site of work. No extra

payment will be made for mixing the sand and also for blanketing material / moorum.

8. DAGBELLING REFERENCE LINES:

The contractor before starting work, is to demarcate with a furrow at least 23 cm wide and 15 cm

deep, the toes of bank and the outside limits of cutting on both sides of the centre line, the

boundary of the bottom and the top of the slopes of the borrow pit, and also lines parallel to and

60 cm. outside the toes of slopes of banks. This is to be considered as part of the setting out of

work and preliminary to his being allowed to break down and this dagbelling is to be maintained

and renewed by him when necessary and when ordered by the Engineer. The cost of this work

is deemed to be covered in the initial rate for earthwork. No extra payment will be paid for this.

9. UNSUITABLE MATERIAL:

The Engineer shall decide materials not suitable for use in the bank and his decision shall be

final and binding on the contractor. When the bank crosses a tank, ditch or bed of a stream the

contractor shall when so ordered by the Engineer clear mud and silt, in order to ensure a good

base before the bank is commenced (excluding the bridge portion wherever it is provided). The

excavations shall be paid under relevant items.

10. PROFILES CENTRE LINES:

Profiles for banks shall be setup where every cross section has been taken, and in flat country

where there may be no cross-sections, at least at every 50 meters on the straight, every 20

meters on curves with radius sharper than 500 meters. Profiles shall also be setup in any

additional places if ordered by the Engineer. The Contractor must at his own expense, provide

all stakes, bamboos, string, pegs and labour etc. necessary in this connection, for profiles

requisite for the correct execution of the work and for making out borrow pit and slopes and will

be responsible to ensure that they are maintained in proper order. The cost of this is deemed to

be included in the rate for earthwork. The Contractor before starting any work, shall take over all

benchmark, center line, tangent points, demarcation and other field stones and pegs and be

responsible for their subsequent preservation and should they disappear or be destroyed after

he had taken them over, he shall pay the cost of their replacement.

11. CLODS:

All large clods shall be broken up in the borrow pit or bank by Workmen specifically detailed for

this work.

12. SIDE SLOPES:

Side slopes shall be carried up simultaneously with the rest of the work and not filled in

afterwards. This can only be ensured by carrying out the work in the whole width from the toe of

slopes going on simultaneously.



13. BACKING TO BRIDGES:

In filling in the approaches of a bridge or spandrels between arches, the earth filling shall be

raised simultaneously with the wing walls in the former case and with the face walls in the latter,

in order that the filling in may be well trodden down under the pact of the labourers. While filling

in foundations and backing to revetments, the earthwork shall similarly be brought up level as

the masonry proceeds. Filling for the backing of bridges or culverts behind abutments and in

floors or as ordered by the Engineer-in-charge. No extra payment will be made for carrying out

the work in the manner prescribed above.

14. USE OF SPILLS FROM BRIDGE FOUNDATIONS:

If the excavated earth from the foundations of a bridge is thrown up to form embankment

backing for a bridge or guide bund, the same shall be deducted from the particular item and no

payment beyond the excavation items of the bridge will be made.

15. RIVER DIVERSION:

When it has been decided to divert a stream adjoining a bank, the excavation for this work is to

be undertaken and completed before any borrow pit work is done at site and all earth out of such

diversion is to be put into the embankment except when the Engineer orders otherwise. This

quantity shall be deducted from the particular item and no payment beyond excavation items for

the diversion will be made.

16. DRESSING OF SIDE SLOPES:

In case of embankments, pitching, and / or providing agricultural soil / turfing will be done on the

finished surface of the embankment. Payments for the above will be under relevant items of the

contract schedule / standard schedules of rates or through non-scheduled (NS) items as per

Indian Railway Practice on mutually agreed rates.

Pitching work shall generally conform to Railway’s specification. Wherever spalls are used as

backing material, smaller pieces shall be laid close to the embankment and larger ones away

from it. The thickness of the backing material will be decided by the Engineer. Payment will be

made under the relevant item of the schedule.

17. CATCH WATER DRAIN:

When required, catch water drains will be constructed outside the top of each slope as ordered

by the Engineer. The material from these drains will be deposited to make a uniform slope from

the edge of the cutting towards the drain and the excavation will be paid under relevant items of

the schedule.

18. BERM AND SPOIL BANKS:

No spoil shall be deposited within a minimum distance of 6 metres from the top edge of the

slope of any cutting. The spoil heap shall be roughly dressed and shall form a continuous bund

along the top of the cutting. In cutting where there is any cross fall, sufficient spoil should be

thrown on the uphill side of the cutting to supplement the catch water drains.



19. DRAINAGE OF CUTTINGS:

In excavating cuttings, special precautions are to be taken to ensure that the excavation may

drain themselves. To ensure this, the central block of earth or gullet is first to be excavated.

This will be done in such a manner that the bottom of the excavation shall wherever possible,

slope downwards from the Centre of the cutting towards the ends. It will be made in such cuts or

slopes as directed from time to time.

20. DETERMINATION OF SIDE SLOPES:

When so ordered, the Center portion of gullet of the cutting shall be first taken out to full width

formation, to enable the Engineer to determine the slopes suitable to the particular cutting or to

different lengths of it. When the gullet is out to its full depth in shallow cuttings, or to the depth of

the first cut in deep cuttings, the side portions of triangular section up to the slopes may be

excavated. In deep cutting the second cut will not be started until the top portion is thus

completed.

21. SPOILS PROPERTY OF THE CORPORATION:

All material excavated from cuttings, suitable for pitching, ballast, masonry or any other purpose

whatever shall be the property of the Corporation except otherwise specified in Schedule and

tender condition, and shall be stacked or disposed of as directed by the Engineer’s

representative. This is deemed to have been included in the accepted rate.

22. EXCAVATION IN CUTTING:

The whole of the excavation in cutting shall be classified and paid for under the following

categories.

i) All soils excluding rock as given in item (ii) & (iii) below. Stone or boulders measuring

under 0.03 m3 shall also come under this category of all soil.

ii) Rock not requiring blasting – this shall comprise of soft rock which can be excavated

by means of bars and picks. Under this class, detached masses of rock measuring

more than 0.03 cubic metre, and less than 0.50 cubic metre, are also included, which

can be completely and properly removed with the use of picks and bars and levers

and without blasting. All fissured stone will also be included in this category.

Alternatively, this can be excavated by attachment of breakers to the excavators.

Rocks / boulders excavated by breakers attachment will also be paid under this item.

iii) Rock requiring blasting – This will comprise of rock in solid beds or masses in their

original position which can best be excavated only by blasting. Compact stone and

boulders and detached rocks measuring over 0.5 m3 will also be included in this

class.



Note: The classification of Cutting will be also decided by Engineer-in-charge or

above authority and the decision of Corporation (EC or higher) on each classification

to paid under Schedule ‘A’ item shall be final and binding. No claim or dispute by

Contractor shall be entertained on classification.

23. BASIS FOR MEASURMENT:

a) Payment for earthwork in bank & cutting will be made on the basis of cross-sections

taken before starting the work and final levels taken after the completion of the work.

The contractors will have to sign ground cross sections in token of acceptance before

starting the work and also cross sections of completed profiles after completing the

work. Any discrepancies in the initial or final cross sections must be brought to the

notice of the Engineer-in-charge, for verification as necessary, classifications of soil

in cutting as instructed by Corporation. The Contractor also has to take level at

different stages / classifications of soil in Cutting as instructed by Engineer-in-

Charge.

b) Should the Engineer-in-charge so desire, he may at any stage of the work order the

contractor to increase or reduce the slopes or widths of any cuttings, or bank or alter

the formation level; the work actually carried out within the scope of instructions given

from time to time shall only be paid for at the accepted rate.

c) Embankments are to be made up to the approved profile of the cross section. No

payment will be made for extra work done outside the specified profile, except

when, such work is ordered by the Engineer-in-charge. Typical cross-section of

Banking and Cutting is attached as Appendix – 16 & 17.

d) No payment will be made for additional earthwork done over and above the

specified profile in the Embankments / Cuttings. Also no payment will be made for

rain water bunds which shall be made on the top of the banks before handing over

the embankments to the Corporation. While calculating the work done on the basis

of cross-section, deduction for all openings including bridge abutments will be made

in full.

e) The rates include lifts to all height for all works and to all depths of the foundations

and banks and nothing extra will be paid against the lift for notwithstanding the

relevant notes applicable to the respective chapters of Unified Standard Schedule of

Rates 2011 of South Western Railway.

f) Excepting where otherwise directed, the general guidelines for cross slopes on

different strata are: inclinations of the slopes in cuttings in ordinary ground shall be

approximately one horizontal to one vertical (H:V = 1:1), in hard rock cuttings

approximately one quarter horizontal to one vertical (H:V = 1/4:1) and in

embankments two horizontal to one vertical (H:V = 2:1). (Where there is ordinary

ground above the rock in cutting, a bench (berm) shall be formed on the surface of

the rock, about 0.6 metres wide, measuring from the top edge of the rock to the

bottom of the slope of the ordinary ground). This is for Guidelines only. The

Engineer-in-charge will advise the actual cross slopes based on actual strata and

the site conditions and this will be final and binding.



g) Plans showing the size, location, depth, slopes, etc. borrow pits for Contractor’s own

earth should be got approved by the Engineer-in-charge before earthwork is

permitted to be started. Care should be taken not to make borrow pits close to

NTPC properties and other structures like telegraph poles, electric poles, level

crossings, bridges, inhabited areas, etc. endangering the drainage / stability of

structures or damage to underground drains, water mains etc.

h) Borrow pits should not be dug from the toe of the embankment closer than minimum

3 m. plus the height of the bank subjected to a maximum of 9 m, unless otherwise

permitted by the Engineer-in-charge. In case of any damage, the contractor should

make good the same at his own expenses. In station limits, no borrow pits should be

dug without Engineer’s prior permission. Where the ground is low and smarmy, the

outer most distance half of the borrow pits is to be excavated first, so that in the

event of the pits being flooded by rain, there will still be ground available for work.

24. FINAL MEASUREMENTS:

a) Work before being finally paid for is to be correctly brought up or carried down to

proper level and to be otherwise completed in all respects. Final measurements will

be taken after satisfactory compaction of earthwork as certified by Engineer-In

Charge. Until the certified completion is obtained by the Engineer, all banks and

cutting are to be maintained by the contractor, who will be held responsible for their

handing over to the Railway in proper condition and for their restoration to such

condition as necessary.

b) The Contractor shall make good all loss due to subsidence wastage on guttering

due to rain, wind, wear, wash or from any cause whatever and shall have no claim

for extra work payment on this account.

c) In addition to the items which are deemed to be covered by the initial rate as already

mentioned, no separate payment will be made for the following items. They will also

be considered as included in the accepted rate of earthwork of the bank:-

1. Construction of approach ramps.

2. Construction of Berms, (making of channel to connect borrow pits for drainage

etc.).

d) All payment of earthwork in excavation shall be made based on Cross-Sections.

25. SPECIFICATION FOR BLANKETING MATERIAL:

25.1 Specification of the material for blanket will be as per latest RDSO guidelines

issued. However, this important aspects are given below for guidelines:

1. The blanket material should be well graded sandy gravel layer of

adequate hardness.

2. Particle size gradation curve should be more or less within Enveloping

Curves of blanket material as shown in sketch and grading percentages

should be within the range as given in the table below-



Sr. No. IS Sieve Size Percentage Passing (by weight)

1 40 mm 100

2 20 mm 80 – 100

3 10 mm 65 – 85

4 4.75 mm 40 – 70

5 2 mm 25 – 50

6 600 micron 12 – 35

7 425 micron 10 – 30

8 212 micron 5 – 22

9 75 micron 3 – 10

3. Uniformity coefficient (D60÷D10) should be above 7.

4. Coefficient of curvature (D30) 2 should be within 1 & 3. D60 x D10

5. Fines passing 75 microns sieve should be 3% to 10%.

6. Los Angeles Abrasion Value should be less than 40%.

25.2 Blanket material should satisfy filter criteria in respect of sub-grade soil, which is

to be protected to avoid upward migration of sub-grade soil causing fouling of

ballast.

Criteria-1 : D15 (filter blanket) < 5 x D85 (sub-grade). Criteria-2 : D15 (filter) > 4 to 5 D15 (sub-grade).

Criteria-3 : D50 (filter blanket) < 25 x D50 (sub-grade).

26. SPECIFICATION FOR PREFERRED FILL MATERIAL:

26.1 In order to ensure a trouble free formation, soils having following characteristics

shall be preferred. a) Fine particles (less than 75 micron size) less than 50%. b) Liquid Limit under 35% and Plasticity Index under 15.

c) Uniformity coefficient (Cu) greater than 7. d) The PH value should vary between 7 & 8.

26.2 The following soils should preferably be avoided.

a) Peat and Organic Soils b) Soils likely to disintegrate easily, like chalks. c) Poorly graded sands with co-efficient of uniformity (Cu) less than 2.

(NOTE: Refer RDSO’s Guidelines for Earthwork in Railway Projects (GE: G-1) July 2003 or the latest version for further details).



27. SETTING OUT:

The centre, longitudinal or face line and at least one main cross line shall be marked by means of small masonry pillars built clear of the point to which the slopes for the excavation will extend. On each pillar there shall be an accurate mark to enable a Level / Theodolite / Total station being set up over it for setting out purposes. These pillars shall be adequately protected from any possibility of damage during the course of work. The provision and protection of the pillars shall be at the expense of the contractor, for which nothing extra shall be paid.

Documents

Special Conditions Of Contract Part B - konkanrailway.com Conditions of Contract – Part – B Kudgi STPP, EW – Package – I, NTPC yard