Monday, April 7, 2008

WMS Railing and Balustrade

WORKS METHOD STATEMENT

RAILING AND BALUSTRADING

TABLE OF CONTENTS


1.0 WORK ORGANISATION
2.0 DESIGN CONSTRAINTS AND COORDINATION
3.0 CONTRACTING METHODS
4.0 PROCUREMENT METHODS
5.0 RESOURCE PROVISIONS
6.0 LOGISTICS PROVISIONS
7.0 MATERIAL MANAGEMENT SYSTEMS
8.0 CONSTRUCTION METHODS AND TECHNOLOGY
9.0 CONSTRUCTION PHASING AND WORKFLOW
10.0 TRAFFIC MANAGEMENT AND MONITORING
11.0 SAFETY PROGRAMME
12.0 QUALITY ASSURANCE AND CONTROL PROGRAMMES
13.0 INDUSTRIAL RELATIONS POLICIES
14.0 ENVIRONMENTAL MONITORING PROGRAMMES
15.0 APPENDICES


1.0 INTRODUCTION

This purpose of this method statement is ensure that the railing (stainless steel) and balustrade works is carried out in a controlled and systematic manner that in all respect confirm to the specification.

2.0 DESIGN CONSTRAINTS AND COORDINATION

Not Applicable.

3.0 CONTRACTING METHODS

Since PCSB is liable for the performance of any Sub-contractor, it is vital that only companies with proven track records in the relevant activity will be engaged as Sub -contractors.

It is acknowledged that before any part of the works can be sublet, the approval of the Employer’s Representative is required.

The Conditions of Contract have been reviewed by PCSB and particularly those conditions in respect of Sub-contractors. The conditions are bespoke for this project and therefore be required to be reflected in any form of Sub-contract utilized on the project.

Please refer to PHOS-CN-010 to PHOS-CN-030 for the Contract Procedures.

4.0 PROCUREMENT METHODS

Please refer to PHOS-PR-010 to PHOS-PR-030 for the procurement procedures.
5.0 RESOURCE PROVISIONS

5.1 Manpower/Labour

The number of manpower/labour to be used during the earthworks activities have been identified in the Manpower Histogram.

5.2 Plant Equipment

Typical plant equipment to be used shall consist of:

• Spectra physics laser level
• Topcon digital thedolite leveling
• Argon welding machine
• Steel welding machine
• Hand drill
• Mobile air compressor



6.0 LOGISTICS PROVISIONS

The logistic control shall be in accordance with the approved Site Logistic Plan and includes wheel wash facilities and traffic management.

7.0 MATERIAL MANAGEMENT SYSTEMS

Please refer to PHOS-CP-040 for the Material Control Procedure.

8.0 CONSTRUCTION METHODS AND TECHNOLOGY

8.1 Handling Material

1. Temporary Storage Area

• Upon arrival of the crates at the temporary storage area, check the quantity of the crates and the crate number against the purchase order and the delivery order to ensure that the correct quantity and crate number are delivered to site
• Unload the crates to the specific area in the temporary storage area
• The crates shall be stored sector by sector for retrieval when they are required to be transported to the required area

2. Installation Location

• Forklifts are employed to transport the crates to a specific where the crates will be hoisted up to the respective floor where the granite are required for installation
• At the respective floor, the crates will be conveyed to the respective installation location where they are required for installation
• Open the crates and remove the crates for installation

8.2 Installation for Floor Finishes – Semi Dry Method

1. Surface Preparation

• The RC floor slab must be aged for at least 6 weeks (preferably longer) before the cement – sand screed is laid
• The RC surface must be dry, sound and free of contamination for example grease, dust, laitance, oil and etc which might impair adhesion between cement – sand screed and RC floor slab

2. Bonding Agent

• To ensure that cement – sand screed adheres securely onto the RC slab surface, a Bonding Agent is recommended to be applied at the interface of the screed and RC floor slab
• For the purpose, mix 1 part Belle Multi Bond, latex admixture to 1.5 part of Ordinary Portland Cement (OPC) by volume
• Mix until a thin slurry consistency is obtained. Mechanical mixing is recommended. Apply bond agent onto RC surface using brush, roller or broom at thickness not more than 1 mm.
• While the bonding agent is still wet or tacky, the cement sand mortar must be immediately placed over it for best bonding results.
• Where a screed is to be constructed as an unbounded screed at thickness of 50 mm or more, a bonding agent is unnecessary. For screed in excess of 50 mm reinforcement with steel fabric / wire mesh at its mid bed is recommended to prevent curling of the screed.


3. Granite Slab Setting Bed

• For installation of white colour 1200 x 600 x 25 mm granite slabs onto matured cement sand screed at internal floor areas, use Belcem Marblefix White, a white colour, water resistant, ultra thick bed, cement based adhesive complying to BS 5980:1980 (MS 1295:1992) fpor a type 1 class AA adhesive or ANSI A 118.1 :1992
• When fixing dense granite slabs or those treated with a water repellent impregnator, Belcem Marblefex must be incorporated with Belcem Admix plus, a latex admixture in replacement of gauging water
• Apply / spread adhesive onto substrate with a thick bed solid notched trowel at trowelled thickness of approximately 6 – 9 mm.
• For large format granite slabs, a thin coat of adhesive (approximately 3.0 mm) may need to be back buttered to the granite slabs back, before it is bedded onto the spread adhesive bed. This will ensure solid bed fixing granite back in full contact with adhesive bed.
• Press or knock granites firmly onto spread adhesive bed followed by slight sliding action to ensure good contact with adhesive bed, eliminate hollow areas or air voids and to adjust the finish level.
• Apply/spread adhesive to small areas at a time (approximately 1 m2 ) to avoid surface drying (skin over) of the adhesive.
• Allow granite slab installation to set for approx 24 – 48 hours before it is subjected to light footed traffic during grouting
• Mix ratio : 6 – 7 liters Belcem Admix Plus to 20 kg Belcem Granite Fix
• Open time : approximately 15 minutes depending on atmospheric condition
• Pot life : approximately 3 – 4 hours depending on atmospheric condition









8.3 Grouting / Pointing

8.3.1 Internal Dry Areas

• For internal wet areas, granite joints should be grouted with Belcem Fine Grout, coloured, water resistant, cement based suitable for joints up to 3 mm wide
• When grouting to internal dry areas, mix grout with clean water only. Mix with a mechanical mixer until a uniform coloured, thin creamy consistency is obtained.

8.3.2 Internal Wet Areas

• For internal wet areas, granite joints should be grouted with Belcem Fine Grout, coloured, water resistant, cement based suitable for joints up to 3 mm wide.
• When grouting to internal wet areas, mix grout with Belcem GT Mix I, a latex admixture in replacement of gauging water. Mix with a mechanical mixer until a uniform coloured, thin creamy consistency is obtained.
• Latex modified grout offers greater resistant to penetration of water, improved durability, flexural strength, compressive strength and adhesion to side of granites.
• Allocate joints of approximately 2mm wide between granite slabs.
• Apply grout with a rubber squeegee / float and ensure that joints are fully compacted with grouting material.
• Clean excess grout promptly using a damp cloth or sponge.
• Allow grout to set for at least 24 – 48 hours (preferably longer) before granite slab installation are subjected to normal service condition.
• Mix Ratio – 8 litres Belcem GT-Mix I (Clean water) : 20 kg (1 : 2.5)

8.3.3 Movement Joints

• Movement joints must be incorporated where necessary; complying to the requirements of BS 5385 : Part 1 : 1990 : Clause 20 & BS 5385 : Part 5 : 1990 : Clause 27.


8.4 Installation for Wall Granite – Toppin Bracket System

8.4.1 General Consideration

• Granite panels shall be installed about 100mm clear of wall.
• All fixing accessories such as brackets, extension plate shall be made of aluminium, washer, bolt, nut shall be made of stainless steel grade SUS 304.
• Where C-lipped channels to be used, it shall be hot-dipped galvanized (for sub-framing).
• All SHS shall be of mild steel and hot-dipped galvanized after fabrication.
• All welding works shall be of fillet weld. Welding works done on site will be dressed off welding spatters and coated over with galvanized paint.
8.4.2 Setting Out

• Setting out shall be carried out based on reference points provided by the main contractor.
• From these reference point, the reference level is transferred to the external surface of the column / wall by using a leveling instrument. The level for the fabricated truss shall be measured by using a measuring tape. A string is tied across the two extreme ends of the elevation at the marked level for the first elevation. The level for all intermediate columns / wall marked off the taut string. This is repeated for the other elevations.
• Similarly gridlines are set out based on the control points provided by the main contractor. The gridline is marked off from the control points onto columns/walls. The grid line on the last column/wall shall be tied back to the gridline provided by the main contractor. If the tie back does not tally with the measurement in the drawing the whole sequence is checked and repeated if necessary.
• After all the levels and grid lines have been marked on each column/wall, the position of the brackets including the hole position are marked using different colours, e.g. yellow or black for restrains brackets and red for dead-load brackets.
• Marked fabricated truss/channel position on column/wall.


8.4.3 Installation

• Drill holes into column / wall to accommodate fixing accessories, using :
1. Long SST plates or L brackets are welded on to the galvanized RHS frame exactly marked for the fixing of the granite panel.
2. Position of the Toppin Back Hole Bolts are marked exactly behind the granite panel to match the location of the long SST plates or L brackets welded on the hollow section frame. Using a special machine holes are drilled behind the granite panels at the exact position, approximately 20mm in depth.
3. The back bolt is fixed and tightened with nut and washer with extension plates. This predrill back bolt granite panels will be hoisted to exact locations of the welded L angle or plate.
4. During installation, the adjustable toppin system slot hole will accommodate any adjustment required about 20mm to suit site conditions.

• Using prefabricate truss / C-channel (where the design require sub-framing) – Only when necessary or site condition confirm.
1. Insert anchor bolt into holes drilled in the column / wall / beam / floor.
2. Mount prefabricated truss / vertical C-channel and tighten nut.
3. Check verticality and alignment of truss / channel.
4. Mount bracket / horizontal channel onto predrilled hole in truss/channel by means of bolt and nut with washer. To the predrilled hole in the free length of the bracket is inserted a dowel pin. Align the bracket with the dowel pin, embedded in Tenax glue, in the predrilled holes in the granite slabs.

• Apply approved sealant to the back and sides of the granite. Allow to dry.
• Each piece of stone is supported at the back by four toppin brackets bolted to SST plates or L angle welded to the hollow section frame.
• Ensure that the first (bottom) row of granite is aligned, leveled and properly fixed o the hollow section frame.
• The next row will be installed on top of the first row of slabs.
• Check verticality and alignment of each slab.
• Leave finished work square, regular, true to line, level and plane with a satisfactory at all junctions.
• Tape a sheet of 1000g polystyrene over granite and cover with plywood to a height of 1.2m for protection of the installed granite.




• of 7 m/ton capacity lifting shackle

Erection Stage – 2

• Upon the completion of stage 1, anchorage bolts are required to be tightened and to check verticality of the erected panel prior to the release for next lifting
• Then proceed with the installation of the lower panel frame marked L2 as shown to check verticality of L2 before the installation of the intermediate tie member marked T1 as shown




Erection Stage – 3

• All intermediate tie members are required to be erected between the lower panel frame L1 and L2 respectively before the installation of upper panel frame. The verticality required to be checked throughout the L1 and L2 structure prior to the installation of U1 and U2
• Similar erection sequence to be followed as stage 1 and 2 for the installation of upper panel frame U1 and U2

Erection Stage – 4

• Then proceed with the installation of main tie girder marked E in position. The erection of the main tie girder to be carried out by a 150 m/ton capacity crawler crane with extended fly jib attached to a main boom.
• At this junction, the working radius of the crane is estimated at 52 meter with a safe working load (swl) of 4.3 m/ton. The ultimate dead load of the main tie girder is approximately 3.6 m/ton the swl factor at this working radius is 15%.
• The main tie girder to be bolted firmly to the wind truss prior to the release of the lift. This will secure the main tie girder in position prior to further attachment of inner tie beams as shown.

Erection Stage – 5

• The next erection sequence is the installation of the main girder marked ‘B’ as shown. The dead load of this section is estimated at 7.90 m/ton at a working radius of 32 meter and the ultimate lifting capacity of the crawler crane is 9.40 m/ton which show a swl factor of 15% within the specified working radius
• In order to ensure the stability of the erected girder during the process, a temporary wire sling with turnbuckle on one end are required to be braced to existing R.C structure as indicated.

Erection Stage – 6

• After the structure has been secured, proceed with the installation of the secondary tie beam marked ‘E’ as shown
• Adjustment on the turnbuckle can be made if necessary for the installation of the secondary tie beam which to be bolted between web of main tie girder marked E’ and ‘B’ respectively

Erection Stage – 7

• Then proceed with the erection of the primary tie beam marked ‘F’ as shown until the structure are completely install





Erection Stage – 8

• Upon completion, then proceed with the installation of the intermediate tie beam marked ‘G’ with both ends bolted to web of primary tie beam marked ‘F’ as shown

Erection Stage – 9

• The erection works on intermediate tie beam are to be carried out completely and tightening of all bolting connection before the erection of outer floor beam
• Then erect the main tie girder marked B1, B2, B3 and D respectively. At this stage, temporary staging is required for access during the installation

Erection Stage – 10

• The intermediate floor beam marked ’C’ are required to be installed in position. All connection joints to be bolted and tightened prior to next erection sequence
• No erection works to be carried out at level 7 until the completion of intermediate. Floor beam marked ‘C’ installation and bolted.

Erection Stage – 11

• Then proceed with the erection of the wind truss structure in fabricated panel frame as per stage 1 to stage 3 erection sequences.
• The tie back of L1 panel frame to R.C structure are required prior to the stability of the erected structure throughout the process
• Ensure that structural verticality and offset distant are being achieved throughout the erection process prior to the installation of main tie girder marked A, B4 and H respectively

Erection Stage – 12

• Then complete the erection sequence for lower panel and secure firmly before proceed to upper panel frame refer to stage 3 for erection sequence
• Similar process of erection as per stage 11 for tie back

Erection Stage – 13

• Then proceed with the erection of the wind truss upper frame as shown
• Repeat stage 4 erection sequence until complete





Erection Stage – 14

• Upon completion proceed with the installation of main tie girder marked A, B4, and H accordingly. All bolting connection joints needed to be tightened prior to the release for next lift

Erection Stage – 15

• Lastly, erect all the intermediate floor tie beam marked G throughout until completed

Erection Stage – 16

• A bird’s eye view of the complete erected view of main atrium structure

8.5 Erection of Granite Frame

Erection Stage – 1

• Preparation works are required to be carried out to determine the level of the granite frame base and if necessary, various thickness of steel shims plates are required in order to achieve to the specified height of the overall structure
• Scaffolding needed to be erected for easy access to erected structure
• The holding down bolt holes needs to be drilled on concrete before the installation of granite frame. Anchor stud from Hilti will be used for this purposed and the bolt have to be installed before the frame is erected.

Erection Stage – 2

• Granite frame is assembly on ground before it is erected tom the specified location. The installation will start with triangle tower and followed by the middle top trusses (intermediate truss in between two towers).

Erection Stage – 3

• The tower will be erected once the framing is done assembled on ground
• Two towers need to be installed before the top middle truss can be erected. Once the middle truss has been erected, the frame is ready for installation of the granite stone by the stone’s contractor

Erection Stage – 4

• The erection process is repeated until the granite frame is fully installed along the grid line



8.7 Erection of Wind Truss

Erection Stage – 1

• Preparation work such as lifting lugs has to be done before wind truss can be erected. 2 numbers of 25 mm thick lifting lug are welded to the side (top) of the wind truss. Partial penetration is applied for this welding connection.
• Upon completion of the above, wind truss are not ready to be erected until the level of column has been carried out. If necessary, various thicknesses of steel shims plates are required in order to achieve to the specified height of the overall structure
• Once the preparation work is completed, wind truss can be erected at any time
• Two cranes are required for this type of erection due to the loads of the truss and also due to the size of the member (long and heavy). Another reason for using 2 cranes is to position the truss from horizontal to vertical and also to protect the truss from damage (dragging on the ground) when lifting is in progress. The cranes that will be used for this erection is one tower crane and one 45 ton crawler crane.


Erection Stage – 2

• When the cranes are ready, the crawler crane will be positioned near the base of the truss while the tower crane will be positioned near the top of the truss. Once the truss is hooked to the cranes ( hooked to the provided lifting lug using shackles and lifting belt), truss will be lift concurrently about few meters (3 to 4 meter) high from the ground
• At this stage, the tower crane will lift the truss higher and higher while the crawler crane will adjust the truss to vertical position
• Once the truss is in vertical position, unhooked the crawler crane from the truss and tied 2 or more long ropes to the bottom of the truss. The workers will use this rope to control the truss from swaying when the tower crane swings the truss to its position. Once the truss is placed to the stump, workers will bolt the truss to the holding down bolt
• However, in order to make sure that the column is shifted when doing the erection, the members in between columns will be installed after the columns are erected. Therefore, scaffolding is required while installation of this member is in progress. The process of erection will be repeated until the entire wind truss is erected.

8.6 Erection of Wind Truss

8.6.1 Surface Preparation

• The surface to be coated shall be inspected to ensure that all the prepared surface meets the requirements of specifications
• Solvent cleaning may be used to remove oil, grease, dirt and other contaminants from surfaces prior to painting
• Ensure the damage, broken and loosely adhering coat are removed and feather edged before recoating
• Verified that time interval between surface preparation and coating is not exceeded

8.6.2 Mixing

• Ensure that the mixing is done in accordance with the manufacturer’s recommendation and the painting manual
• Monitor the mixing to see that a through blending of the pigment and the vertical or the component accomplished weather by approved mechanical vibrators or by manual
• Monitor the addition of catalysts, thinner or other constituents to ensure that they used in strict accordance with the manufacturers recommendation
• It may be necessary to consider the use of sieves or strainer to ensure proper mixing and / or blending
• Make sure that cleaning solvent and thinner used to clean brushers, spray equipment or containers is not added to the coating material

8.6.3 Application

• Ensure the coating material applied the number of coats and dry film thickness of each coat is as shown in the approved painting schedule
• No coating system will be applied to any surface whose temporary is below 5 degree C or above 60 degree C unless the coating is especially formulated for these conditions
• Equipment and method of application shall be recommended by the coating manufacturer and approved by the client representative
• Verify that coatings are applied events without runs or sags
• Ensure that each coat has the correct dry film thickness before applying the next coat
• Verify the coating are cured the specified times / temperatures as recommended by the manufacturer


8.6.4 Thickness

• Dry film thickness of coating on steel or ferrous surface shall be measured with a thickness gauge such as the Elometer or Microtest magnetic type gauge or approved equals
• Fry film thickness of coating on non ferrous surface shall be measured with micrometer depth gauge or approval means
• When wet film gauge are used during application, a reasonable allowance shall be made for the subsequent loss of thickness due to the evaporation of volatile solvents when present


8.8 Installation of Spandek

• To measure the exact length and quality of roofing sheet on site
• Preparation of cutting list for rooring deck supplier to roll the metal deck as per require quantity and length
• Install spandek by following the bellows steps :

a. Measure spacing between box beam to box beam
b. Calculate the distance to be off set from beam for the first piece of spandek
c. Lay the first piece of spandek and use self tapping screw to screw at all purling location
d. Lay the second piece of spandek with the end rib lapping to the first piece
e. Repeat step ‘d’ until completion

• Care should be taken to ensure that sufficient workers are available to move the roofing sheets in unison without causing any damage to the roofing sheets
• Install ‘L’ shape flashing along roofing sheet in contact with the box beam.


9.0 CONSTRUCTION PHASING AND WORKFLOW


During secant wall and bored piling construction, excavation for ground anchor installation and basement formation will commence in available areas, generally moving from grids 27/H towards 1/A.


10.0 TRAFFIC MANAGEMENT AND MONITORING

The Logistic Manager and the traffic management contractor shall be responsible for the management and control of the traffic in and out from the construction site.


11.0 SAFETY PROGRAMME

Please refer to PHOS-HS-010 Health and Safety Plan.


12.0 QUALITY ASSURANCE AND CONTROL PROGRAMMES

Please refer to Appendix 15.1 for the Inspection and Test Plan and Appendix 15.2 for the Checklist.


13.0 INDUSTRIAL RELATIONS POLICIES

Not Applicable


14.0 ENVIRONMENTAL MONITORING PROGRAMMES

Please refer to PHOS-EMP-001 Environmental Management Plan


15.0 APPENDICES

15.1 Inspection and Test Plan

15.2 Inspection Checklist Form
15.3 Job Safety Analysis
15.4 Erection of Lower Roof (Trellis)
15.5 Erection of Floor Beam (Main Atrium)