CLIENT: DELHI METRO RAIL CORPORATION LTD.

CONTRACTOR: ITD – ITD Cem JV

Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

METHOD STATEMENT OF POT/PTFE BEARING INSTALLATION

Issued for Planning QA/QC Project

Approval Manager
Revision Date Description Prep’ By Chk’ By Rev’ By App’ By
of revision (ITD– (ITD– (ITD– (DMRC)
ITDCEM ITDCEM ITDCEM
JV) JV) JV)

Page 1 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

CONTENTS
i. Preamble
1. Responsibilities and Authorities
2. Safety
3. Risk Hazard
4. Precaution to be taken before Installation
5. Material
6. Finishing of Material
7. Marking of Bearing
8. Installation of Bearing
9. Tests on bearings
10. Bedding for Bearing
11. List of Enclosures

Page 2 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

PREAMBLE
Construction package BC 21 for DMRC is consisting of construction of
elevated viaduct for Phase-II of Delhi MRTS Project on Qutub Minar-
Gurgaon corridor from Delhi border to Sushant Lok. This includes five
elevated station buildings and viaduct.
This method statement illustrates the different activities included in the fixing
of POT/PTFE bearing for three track structure (Pier P204 to pier P218).

1. RESPONSIBLE AND AUTHORITIES

1. The Construction Manager is responsible for coordinating construction

operations. He is the final responsible individual for safety, quality and
production of the project within the scope of work of ITD-ITDCEM JV.
2. The Quality Assurance Manager is responsible for initiating Work
Methods and Inspections and Test Plans covering all construction aspects of
the project. He shall initiate a preparatory meeting between all parties
involved in order to carry out appropriate reviews. Duties include all
aspects of field engineering under the scope of this work method as well as
responsibility for the overall Quality Control of the work performed.
3. The Field QC Engineers are responsible for ensuring that the work subject
of this Work Method is carried out according to the structural and quality
requirements of the Contract Documents and the ITD-ITDCEM JV Quality
Management Plan.
4. The Safety Coordinator is responsible for reviewing Safety Instructions to
ensure safe conditions for the work performed under the work methods.

Page 3 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

5. The Manager of Survey is responsible for the design, development and

formulation of the Survey Methods referenced in this document and the
document review if such is required by the design department. This
individual is responsible for review of the final survey data results and a
transfer of the Survey Design Information to the QA Department.
6. The Survey Crews are responsible for the execution of all survey activities,
under the control and supervision of the Survey Manager.
7. The Shift-in-Charges (SIF) are responsible for the direct field applications
of all setup Each SIF is responsible for quality as it relates to his portion of
the work.

2. SAFETY

During the execution of the work, area will be properly covered with
barricading / plastic tape with suitable supports. It will be maintained
throughout the construction activity. A suitable access by ladders will be
maintained. All persons working in this activity area will wear safety helmet
and will take all necessary safety precautions. Every day ITD-ITD CEM JV site
engineer will inspect the scaffoldings, working platforms, and ladders. etc., for
ensuring safety and record his observations in Form No. ITD/QA/20.

3. RISK HAZARD

An assessment on risk hazard has been done; the copy of same is enclosed with
this method statement. All listed precautions therein shall be taken during work
to minimize the risk

Page 4 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

4. PRECAUTION TO BE TAKEN BEFORE INSTALLATION

Following are the precaution to be taken before installation as per CL930.1

IRC: 83 (part III) – 2000.

1. Bearings should be installed with care to ensure their correct functioning in

accordance with the design for the whole structure. Bearings shall be so
located as to avoid the accumulation of dirt and debris likely to interfere
with their performance and the structure so detailed that water is prevented
from reaching the bearings.

2. In order that moving surfaces are not contaminated, bearings should not
normally be dismantled after leaving the factory premises, but if for any
reason they are, then this should only be done under expert supervision.

3. Transfer of superstructure weight on to the bearings should not be allowed

until sufficient strength has been developed in the bedding material to resist
the applied load. Temporary clamping devices should be removed at the
appropriate time after installation, before the bearings are required to
accommodate the movements.

4. Suitable temporary supporting arrangements under bearing base plates

should be made to accommodate thermal movement and elastic deformation
of the incomplete superstructure, if necessary. Such temporary supports, if
provided, should be compressible under design loading and removed once
the bedding material has reached the required strength. Any voids left as a
consequence of their removal should be made good using the same type of
bedding material. Steel folding wedges and rubber pads are suitable for
such temporary supports under bearing base plates.

Page 5 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

5. Bearings shall be located so that their centerlines are within  3 mm of their

correct position. The level of a bearing or the mean levels of more than one
bearing at any support shall be within a tolerance of  0.0001 times the sum
of the adjacent spans of a continuous girder but not exceeding  5 mm.
Bearings shall be placed in a horizontal plane within a tolerance of 1 in 200
in any direction unless otherwise specified, even under superstructure in
gradient.
6. Handle carefully and where necessary with adequate handling equipments
as cranes, etc.
7. Store in a clean dry place.
8. Do not leave bearings uncovered.
9. Keep the Bearings and surrounding area clean.
10. Ensure that the fixing is uniformly tightened.
11. Install Bearing with qualified supervision.
12. Permitted installation tolerance of the bearing from the plane of sliding has
to be maintained.
13. Take special care to support top plates when casting in-situ concrete.

5. MATERIAL

1. Top plate, Piston and POT/bottom plate will be made up of cast steel grade
280-520W of IS: 1030. Anchor bolts shall confirm to IS: 1364.
2. The material such as PTFE lubrication, confined elastomer, stainless steel
and internal seal will be as per IRC: 83 (part III)-2000
3. Stainless Steel will confirm to AISI: 316L with the sliding surface finished
smooth.

Page 6 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

4. Painting on non-working surface shall be as per IRC: 83 (part III)-2000.

5. Confined PTFE will be of unfilled quality and will have required
properties regarding tensile strength etc. as per BS: 5400 Sec 9.2 and BS:
3784 grade A.
6. The confined Elastomer inside POT will have following properties as per
IRC : 83(Part II)
a. Hardness : 60 +/- 5 IRHD (IS -3400) part II
b. Min. Tensile Strength : 17 Mpa (IS -3400) part I
c. Min Elongation at Break : 400 % (IS -3400) part I
d. Max. Compression Set : 35 % (IS: 3400) Part X
e. Accelerated ageing : As per IRC 83 (Part II) table -1
i. Maximum change in hardness : +15 IRHD
ii. Maximum change in tensile strength : -15%
iii. Maximum change in elongation : -30%
7. Anchor bolts material as per grade 10.9 of IS: 1363 and sleeve material as
per IS: 2062 and detail of threaded as per IS: 1363, Accessories confirming
to IS: 2062.
8. The stainless steel will be welded on the backing plate.
9. Suitable nos. of washers are to be used as a packing to tighten the anchor
bolts with bearing top plate and bottom plate.
10. Internal Seal will be proven type Poly oxy Methylene (POM) sealing
chain. Properties as specified in table 2 of IRC : 83 (Part III)
11. External seal will be glued with POT by Adhesive material (SPEB make).
12. All welding will be manual arc process confirming to IS: 816 and IS:9595
with electrode as per IS:814, pre heating and post heating weld stress
relieving to be done if required.

Page 7 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

13. The outside diameter of the piston shall not be more then 1 mm less the
inside diameter of the pot at the interface level of the piston and
Elastomeric rotational element.
14. The dimensional tolerance of confined PTFE will be as per CL.927.1.3
IRC: 83 (part III) – 2000.
15. Manufacture tolerance will be as per CL.927.1.1 IRC: 83 (part- III)-2000.

6. FINISHING OF MATERIAL

Finishing of material as per IRC: 83(part III) – 2000. CL.927.3

1. All non working surfaces will be coated with Two coats of Epoxy Primer
and or more coats each of high built Epoxy paint reinforced with MIO
(Micaceous Iron Oxide) and finish paint after shot blasting to SA 2 ½
quality as per IS: 9954 and total dry film thickness of protective coating
should not be less than 160 microns. All the finishing material i.e. Epoxy
primer, epoxy paint and finishing paint will be of Berger or Asian paints.
2. Bearing component to be embedded in concrete surface or surface of any
component to be in contact with concrete surface will be given a coat of
epoxy primer.
3. Anchor sleeves will be Hot Dip Galvanized coated @ 300 gm/m 2 before
dispatch.
4. The mating surface of the cylinder of the POT and that of the piston shall
be Metallurgical Hardened to a valve not less than 350 BHN.
5. The Silicon Grease will be applied at PTFE stainless steel interface after
testing.

Page 8 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

6. At the time of fabrication all the steel surface expose to atmosphere, except
stainless steel and metal surface to be welded, will be shop painted. Prior
to painting, the exposed steel surface shall be cleaned.

7. MARKING OF BEARING

1. The bearings will be transported at site after final acceptance of it.

2. The bearings should have suitable index marking made of indelible ink ,
which will be visible after installation, identifying following information
 Name of manufacturer.
 Month and year of manufacture.
 Pier number and Bearing mark
 Type of bearing
 Load and movement capacity.
 Centerline markings to facilitate installation.

8. INSTALLATION OF BEARING

The installation procedure as given by the manufacturer is as fallows

1. Template is prepared of exact dimension i.e. P.C.D of Bottom Plate.

2. Prepare a Casing or Shattering for the pedestal with inner dimension as per
the pedestal size.
3. The Pedestals should be cast keeping pockets for Anchor Sleeves with 75
Dia. X 200 mm long in the height.
4. Cast the pedestal by using the Casing & Template.

Page 9 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

5. Cast the pedestal by specified Grade of concrete is as mentioned in the

drawing. Allow it for set.
6. Place the Anchor sleeves in the pocket of the pedestal.
7. The Bearings are placed over the pedestal as per the specified drawing.
8. Position the bearing by level & lines (axis).
9. Bedding material (viz., Conbextra GP2) is poured over the bearing area &
pocket.
10. All the Bolts are tightened to the Anchor sleeves.
11. Formwork around the bearing should be carefully sealed to prevent leakage.
12. Sliding plates should be fully supported and care taken to prevent tilting,
displacement or distortion of the bearing under the weight of wet concrete.
13. The bearing should be protected during concreting operation. Any mortar
contaminating the bearing should be completely removed before it sets.
14. Remove the temporary clamping before Pre-stressing or after superstructure
achieve strength or before the bearings are required to accommodate the
movements.
15. Clean the side of the Bearing.
Installation is also checked by the manufacturer’s representative.
The site where installation is in progress is provided with adequate lighting
arrangement.

9. TESTS ON BEARINGS

Sampling, testing and acceptance consideration will be made on the lot

basis. A lot shall be defined as those bearings presented for inspection at
specific time or date. The lot shall not exceed 25 nos. of Bearings

Page 10 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

1. VERTICAL LOAD TEST

Bearings shall be load tested for vertical load equal to 1.25 times the
specified design load. The test shall be applied and held for 30 minutes.
The vertical deflection under sustained load shall not increase by more
then 4% of Elastomeric pad thickness. The load shall then be removed and
the bearing shall be dismantled and examined.

2. FRICTION TEST
A pair of sliding bearing selected at random shall undergo friction test.
Friction test for sliding shall be performed at constant vertical design load.
The horizontal load shall then be applied till sliding occurs. The co-
efficient of friction shall be determined on the basis of applied vertical load
and horizontal load. The measured sliding coefficient of friction shall not
exceed 3%. The value of co-efficient of friction shall not exceed 2/3 rd of
the value specified in CI. 926.2.4.2 of IRC: 83(part – III) – 2002
depending on the actual average pressure on PTFE due to applied vertical
load.

3. ROTATION TEST
Rotation test for bearing shall be performed at constant vertical load equal
to design load and design rotation. The load shall be removed and bearing
shall be dismantled and examined.

4. PROOF LOAD TEST

A bearing shall be tested as defined in IRC – 83 part – III.
The bearing will be visually examined both during the test and upon
disassembly after the test. Any resultant visual defects, such as extruded or
deformed elastomer or PTFE, damaged seals or cracked steel shall be
cause for rejection.

Page 11 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

10. BEDDING FOR BEARING

1. The choice of bedding materials is influenced by the method of installation

of the bearing, the size of the gap to be filled, the strength required and the
required setting time. When selecting the bedding material, consideration
should therefore be given to various factors like type of bearing, size of
bearing, capacity of bearing, construction sequence and timing, early
loading, friction requirements, access around the bearing, thickness of
material required, design and condition of surface in the bearing area and
shrinkage of the bedding material. Suitable high strength, free flow, non-
shrink, cementations grout, viz., Conbextra GP2 of Fosroc or equivalent is
recommended.
2. To ensure even loading on bearings and the supporting structures, it is
essential that any bedding material whether above and below the bearing,
extend over the whole area of the bearing.
3. Bearings shall be bedded over their whole area. After installation there shall
be no voids or hard spots. The top surface of any extension of the bedding
beyond the bearing shall have a downward slope away from the bearing.

Page 12 of 13
CLIENT: DELHI METRO RAIL CORPORATION LTD.
CONTRACTOR: ITD – ITD Cem JV
Contract Package: BC-21
PROJECT NAME: PART DESIGN AND CONSTRUCTION OF VIADUCT AND STRUCTURAL WORK
OF 5 ELEVATED STATIONS (GARDEN ESTATE, SIKANDERPUR, DT CITY CENTRE, IFFCO
CHOWK AND SUSHANTA LOK) ON QUTUB MINAR - GURGAON CORRIDOR OF DELHI MRTS
PROJECT
Revision: R1
Method Statement Of POT/PTFE Bearing Installation

11. LIST OF ENCLOSURE

 Typical Cross Section

 Sketch showing Bearing Arrangement and Deign data for POT
bearing
 Pre Installation and Post Installation Checklist.
 QAP of the Manufacturer.
 Inspection and Test Plan
 Organization Chart for Fixing POT/PTFE Bearing
 Risk Assessment Sheet
 Emergency action Plan
 Check List for Safety
 Single Line Electrical diagram

Page 13 of 13