Quy trình thi công tổng hợp method statement

Those shall be studied by the Contractor to compare with tender document; existing work and the comments shall be forwarded to the Owner for accuracy or reliability of document for the n

Method statement

A general

Content consists of method statement on construction technology and organisation of contract package - Topaz tower block 3 and 4 shown in drawing from No.P2A/S000/2 to No.P2A/S-259/7 and other archetectural drawings of The Saigon Pearl Development

Project at 92 Nguyen Huu Canh street, ward 22, Binh Thanh district, HCMC, Vietnam Document includes:

1- Receiving handing over possession, boundary, cordianation system located points and other related documents

2- Site preparation and mobilisation of manpower and equipment

3- Construction of RC structures (column, wall, beam and slab)

4- External and internal brickwork

5- Plastering and tiling work

6- Co-ordination with other contractors during construction (M&E, earthing, telecommunication & media, alluminum, interior contractors ect.)

7- Completing, cleaning and handing over

B Technical and organising method

I- Receiving handing over possession, boundary, cordianation system located points and other related documents

Possession is to hand over to the Contractor together with documents and drawings by the Owner after contract is awarded

1.1 Receiving handing over possession, boundary, and cordination system located points

A joint handing over is undertaken between the Owner/Consultant and the Contractor Handing over is clearly show the location, project boundary on land where to be confirmed

by the Owner/Consultant for contractor’s possession of package Required possession and elevation are shown on “Handing over lay out” and “handing over elevation”

The Owner/Consultant provides handing over means elevations and located points (in accordance with “located points map” and basing on that, the Contractor is to prepare existing coordination net (actual topography) The Contractor shall check the actual conditions of foundation and basement package in coordination and records is submitted to the Owner and/or the consultant

Taking over the possession is directly conducted by Contractor’s site manager and executed by site engineers Minutes of handing over are to confirm by relevant parties by authorized individuals Boundary shall be made by fencing system to close construction area

Surveying system is developed from basic points by professional surveying team and specialized equipment including therdolite, level and electronic total station Equipment used for surveying work is to list on table of proposed equipment

1.2 Taking over Basement’s as-built drawings

Reference to this document to see how is work done and solution of best organization for superstructure subjected to the situation For example, any error of elevation, centerline may be found are not complied with design, a suitable solution for superstructure is based

on the Owner/designer’s instruction

Finishing work of basement is checked by surveying equipment and surveyors, structural engineer and architectural experts Written report of any failure may found shall be

submitted to the Owner and Construction Manager within 7 days since as-built drawings to

be passed

1.3 Taking over superstructure technical design document

Technical documents are fully provided by the Owner in accordance with tender documents for all works related to this package Those shall be studied by the Contractor to compare with tender document; existing work and the comments shall be forwarded to the Owner for accuracy or reliability of document for the next works

1.3.2 Organizing requirement:

The Owner and Contractor by TRANSMITTAL confirm taking over technical document Comments of reality and accuracy or other may found by a team of construction experts or architects from their studying shall be submitted to the Owner for their review Written report

of any failure may found shall be submitted to the Owner and Construction Manager within

30 days since technical documents to be passed except force majored (if any) may found during construction

Handing over sequence is shown on lay out of “possession handing over sequence”

II- Site preparation and mobilisation of manpower and equipment

After having possession from the Owner, site preparation and mobilization of manpower and equipment are to start promptly

2.1 Temporary and minor works

This work is including construction of temporary site office, other temporary facilities such as toilets, water tanks, storage and stockpiling areas and fencing ect

The facilities shall be arranged at suitable areas near the construction site to ensure not affected to construction works and permanent works as well as to avoid relocated many time when required In fact possession area is very narrow which is not enough space for worker’s camps and to overcome this situation we already prepared to rent house outside for them near the site for convenience during contract duration

(See layout of temporary works No BPTC – 01)

2.1.1- Site office contains of 2 areas:

Site engineer (supervisor) room and staff room Site engineer room is flaming camp roofed

by tole 60m2 enough space for 24 site engineers Staff room is 3 office containers-40 feet and well equipped where includes Project manager’s office, engineer’s room, administrator’s room, accounting room, material control room enough for 20 people working in

2.1.2- Staff’s accommodation:

Is 500m from the site that is very convenient for traveling and arrangement of work among them in the case more working shifts as required Personnel proposes for this project is 50 staff stayed in 3 storey houses having landing area of 70m2 per house

2.1.3- Worker’s accommodation:

Is about 1 km from the site with 4m2 average areas per head, which is equipped electrical, water supplying, and telecommunication system

2.1.4- Boundary fencing:

Is corrugated sheet 2.5m height to separate construction area to others and to ensure security of project as well

2.1.5- Water supplying

Water tank: The main water tank for the whole project can contain of 200n3 Water used is from City public system Every five (5) floor puts one (1) water tank 5m3 and supplied from main tank by water pump P-H to be fixed at basement tank

The main supply system to upper floor is vertical tin coated - steel pipe D42-20bar sharing

to every small tank by branches D27

2.1.6- Worker’s toilet:

Every 5 floor put 1 mobile toilet per block In order to keep hygiene and cleaning toilet is located next to water tank Discharged pipe of toilet is fixed vertical down to sewage tank of project This type of discharged pipe is PVC-class 3-D114-15 bar Each water tank supply water for that floor and other 4 floors under it

2.1.7- Electrical cable:

To be connected from transformer-500KVA by main cable size 4 x 120 to site general electrical station where can transmit mobile and fixed sub-loads to everywhere

Mobile sub-load consists of electrical hand machinery, welding machine, concrete vibrator, and lighting to be connected by cable size 3x10 + 1x6 Every block is provided 2 mobile electrical boxes for formwork, rebar work and concrete work The length of cable is subjected to the height of building plus movement

Fixed sub-load consists of tower crane, passenger hoists, water pump, security lights and electrical box at every 2 floor per block (this is to use for finishing works later) Each tower crane, passenger hoist, security light and water pump are connected to automat and cable line that have suitable capacity to sub-load Transmission line to small stations at upper floors is a main line size 3*35+1*25 and branched to small station every 2 floor

2.1.8 Material storage:

It is provided convenient places for income, stockpiling and transportation during construction work According to the proposed schedule, storage areas are planning as follows:

Rebar and rolling steel stockpiling areas is 10cm concrete cast provided curb to keep dry from wet or water With the consumption of rebar about 400 ton per month, the required area is at least 200 sqm This area is located near fabrication area and within tower crane arm reaching

Cement is stored in flaming house roofed by tole With the consumption of cement per month about 300 ton per month mainly for plastering and brick works, the required area is at least 100 sqm This area is located near the hoist for convenience of moving up

Sand area:

Brick area:

2.1.9 Mechanical service area:

This kind of work is very important for construction activities as of steel formwork, and platform and other maintenance works and services for equipment Mechanical workshop is equipped 3 welders – 3 phases, 1 rebar bender-cutter, 2 pipe steel cutter 2 gas torchlights, 1.5 ton sewer, table welder and other handle machineries ect This workshop is ran by a qualified engineer with 12 to 15 mechanics at level 3/7 to 5/7, possession area is estimated

150 sqm located at site Workshop is steel flaming house roofed by tole

Temporary works and minor works shall be started as long as the Contractor received handing over form the Owner Every preparation work is operated by site engineer/supervisor and construction teams (Electrical team, plumbing team and mechanical team…) This period is planed for 7 days shown on master program Lay out of temporary and minor works is shown on “site organization lay out” Especially, the mechanical workshop is to start immediately as much as possible to fabricate various standard formworks for structure work from ground floor

2.2 Equipment mobilization

As long as the fencing finished equipment shall be mobilized accordingly in compliance with submitted progress The main necessary equipment is selected according to the Contractor capability, project conditions and project schedule Following is the selection solution of tower crane and passenger hoist, the main equipment for vertical transportation

2.2.1 Tower crane:

To fit with the height of the building 138,74 m proposed tower craned is at least 150 m Tower crane is used for lifting up materials and concreting works It is proposed using bucket 1.0m3 with total load including concrete equal to max = 2,8 ton

The critical path of project show the column concreting and top roof’s wall with estimated maximum quantity of wall is 160 m3 per 48 hour per 2 days The max load lifting speed is 70m per min Roof top height is 130m

Time of one cast concrete is equal time of concrete discharged to bucket plus time of lift up and down plus time of pouring = 1+4+5 = 10 minutes Capacity of pouring concrete for wall

= 48 hours x 60/10 = 288m3 > 160m3 This is satisfied the requirement

Basing to the above conditions together with our own equipment contractor intends install

02 tower cranes WOLFFKRAN135EC2 made in German with 150 m height, 50m arm reaching and Max load 8 ton and Min load 1.2 ton

Locations are showing on “lay out of site organization”

Foundation of tower crane is put on top of pile cap on RC piling or bored pile It is best solution if piling and basement contractor prepare locations prior to superstructure work coming Calculations of the same are provided and checked as other foundation structure

To stabilize supporting every floor rising up bracings are tighten back to the main RC structure of building as manufacturer’s instruction

2.2.2 passenger/material hoist:

During construction of superstructure most of instruments and materials will lifted up by tower crane, therefore passenger should be used for moving people and/or material to upper floor and for brickwork and plastering as well

This kind of hoist has maximum carrying load of 1000 kg equivalent to 12 persons per trip with the height of building is 138.74m so hoist must be required to meet this condition This

is a compelling condition subjected to the height of building

To meet with above conditions we select model CS100 made in China –max load 1000kg – standard lifting height 90m – lifting speed 40m per minute It is intended installation of 2 hoists Locations have been shown in layout No BPTC – 02; BPTC – 03

The maximum demand at critical time of schedule is hoist up material for nine top floors doing the finishing works within 3 months It is calculated about averagely (66x1.8x1.5x9/90) = 17.82 ton per day at the height of 120 m with speed of 40 m per minute The capability of trip is estimated 2+3+2+3 = 10 minute

Max trips per day is 24+60/10x50% = 72 ton

Max volume lifted up per day is 72x0.5 ton per trip = 36 ton

Selects 2 passenger hoists-1000kg-standard lifting height …-speed 40 m per minutes per block Locations show on “lay out of site organization”

Hoists are to brace to the main structures of building in compliance with manufacturer’s instruction

To ensure the continuous communication between on land, tower cranes and hoists walkie-talkie system – KENWOOD made in Japan – speaker DAIMOND battery made in China should be provided

2.2.3 Main equipment selected:

Main equipment shall be mobilized to site according to the schedule listed in table bellows:

No Description of equipment

(type, model, brand) Unit Qty

Manu year

Original country

5 Air compressor 2,5m3 per minute nos 2 2005 China

10 Stable concrete pump 150m, 60m3/h nos 3 2004 Japan

14

Pre-fabricated for 2 floors m2 10.00

Equipment shall be mobilized to site based on the schedule of work and purpose of work Equipment is required to check by relevant parties before and during construction The brand new one is to attach the mill’s certificate For example, tower cranes are to install first for all preparation work and site arrangement Passenger hoists are proposed to install after concrete cast for transmission slab to support the working platform for hoist up formwork to upper floors and other material for finishing work Same as sequence to external scaffolding should be installed Materials, timber, plywood ect are stockpiled as per progress principally that non stopped work and non wasted material and non occupied area as well

2.3 Manpower preparation:

We learned that this is a very big scale Project so that our staff have been selected to joint this contract are our best managers, professional engineer and skilled full workers who have jointed in many high standard Projects before

2.3.1 Management staff:

 Project Manager (01 person)

This position is pointed a construction engineer specialized in civil engineering construction – industrial in at least 15 years working experience who directly manage the work on sites especially in the similar projects

 Site manager (01 person)

This position is pointed a construction engineer specialized in civil engineering construction – industrial in at least 10 years working experience who directly manage the work on sites especially in supplying materials

 Financial manager (01 person)

This position is pointed a person who has at least 5 years working experience especially in capital management and budget program

 Translator (02 persons)

This position is pointed a person who has at least 5 years working experience especially in similar projects

Technical management:

Equipment and machinery service: 01 mechanical engineer with 6 years working experience and other 3 engineers who can control, arrange and maintain equipment for all over the project

Administration: This group includes 10 persons who manage the administrative and security works

Material management: This group includes 4 persons who provide materials for project and co-ordination with suppliers for delivery and management

Safety, environmental and medical management: 01 safety officer and 4 assistants who have at least more than 3 years to make the suitable program for safety, environmental and medical plans

04 engineers/supervisors are in charge to formworks

04 engineers/supervisors are in charge to reinforcement works

02 surveyors are in charge to surveying works

04 archetects/superviros are in charge finishing works

04 archetects/superviros are in charge designing, as-built and quantity works

Material management: This group includes 3 persons who provide materials for project and co-ordination with suppliers for delivery and management

07 staff are deliverying, supplying and seecking for small materials

Administration: This group includes 2 persons who manage the administrative and security works

06 security guards

Safety, environmental and medical management: 01 safety officer and 2 assistants are

in charge to safety, environmental and medical works

Project manager in Contractor’s rules conducts the above titles

2.3.2 Construction team:

Including construction teams working directly on site with capability estimated in 8-hour working shift

Formwork team: 04 teams - 25 workers per teams.

Reinforcement teams: 04 teams - 20 workers per teams.

Concreting teams: 02 teams - 15 workers per teams.

Brickwork and plastering teams: 04 teams - 25 workers per teams.

Tiling team: 04 teams - 20 workers per teams.

Common, cleaning and minor works: 02 teams - 20 workers per teams.

Mechanical workshop: 01 team - 15 workers

The maximum number of work may mobilize to site in 01 working ship up to 425 workers In the case, works are required to double, contractors is complied with

Supervisor and supervisors conduct those teams as per schedule, which is described in detail site organization

2.4 Material suppliers:

Together with other preparation works, contractor shall co-ordinate with suppliers

Material resources: Brick, sand, rebar, cement, ready mix concrete, timer, and formworks shall be signed supplying contracts with big supplier ing HCMC Quality of material shall be agreed with suppliers basing on the specifications, supplying progress and realiable pricing

2.4.1.Cement:

Contractor suggests using Holcim and Ha Tien suppliers grade PC40 for this project

2.4.2 Sand:

2.4.3 Reinforcement:

2.4.4 Wiremesh:

2.4.5 Concrete block:

2.4.6 Brick:

2.4.7.Cold profiled and pipe steel:

2.4.8 Plywood, bamboo plywood and timber:

2.4.9 Plastic formwork- Fuvi:

2.4.10 Various scaffoding and supporting post:

2.4.11 Ready mix concrete: Holcim, Linh Thanh, UNI EASTERN VIETNAM CO., LTD, Tra

Mi concrete, Mekong Concrete, Lafarge conrete are big suppliers who can satisfy the capacity.

2.4.12 Chemical and admixture (Sika): Special chemical and admixture using for complecated and special structure or works shall be supplied by Sika Vietnam Co., Ltd.

III- Construction method for RC superstructure (column, wall, beam ECT)

3.1 RC column:

RC column of building is installed through up from basement to transmission slab with cross-section 1x2m; 1x1m Height of column from 3.8m to 4.45m

3.1.1 Formwork:

Bamboo formwork is tied back by anchor system and braced properly to the dimension of column see in detail shop drawing of column formwork

It is required to follow the surveying data provided To ensure the dimension before formwork installation the points must be fixed by welding or drilling Use bolts for anchoring and bracing to provide properly supporting Vertical formwork is supported by supporting system and checked by plump and thedolite Before concreting required elevation should

be marked to avoid failure of the nest works Formwork is to provide firm, tightness, alignment and vertical Other data must be followed design requirement Formwork can remove after 48 hours

3.1.2 Rebar works:

Reinforcement includes main rebar and stirrup Main rebar has bigger diameter they are all fabricated on site at fabrication area and hoist up by tower crane Installation of rebar is to supervise by site engineers in accordance with design to ensure the lapping, spacing, location and dimensions

3.1.3 Concrete works:

Using tower crane for concreting, it is proposed using bucket 1.0m3 with total load including concrete equal to max = 2,8 ton Concrete cast in every 50cm layer well compacted by needle vibrator D40 mm Curing concrete is to meet the specification

Mixed design shall be made for every single structure in particular condition

3.2 RC wall:

RC wall has average thickness of 30 cm with same sequence of concreting column except some particular works as follows:

Layer cast is thinner than column but the height is more so vibrator and well compaction must be provided during concreting to avoid any mistake may have later

Thickness of wall is small but content of rebar is much so spacing and covering layer must

be provided properly, especially in case join is lapping

During concreting using directed tranking from bucket to location and monitoring the deflection of formwork or unforeseeable thing may have (if any) to treat in time

3.3 Slab and beam of podium floor:

3.3.1 Formwork:

Supporting system for slab and beam of ground floor includes: A scaffolding at every height 0.75m, 1.0m, 1.5m with D=50mm, jacks adjust during installation, timber size (80 x 100) mm together with cold profiled size (50 x 50 x2.5) mm, 1.5cm bamboo plywood for formwork Sequence of installation shows on shop drawing for formwork of ground floor

Formwork installed is required firm, alignment, tightness, vertical, centerline, elevation and flat

Sequence of installation is stated in detail method bellows:

3.3.2 Rebar:

Reinforcement includes main rebar and stirrup Main rebar has bigger diameter they are all fabricated on site at fabrication area and hoist up by tower crane Installation of rebar is to supervise by site engineers in accordance with design to ensure the lapping, spacing, location and dimensions

Sequence is bottom formwork of beam -> reinforcement of beam -> beam side formwork -> slab formwork -> slab rebar -> beam and slab concrete

3.3.3 Concrete:

All pre-pouring concrete works are checked before concreting like inspection of formwork and rebar, concrete supplying, pumping system, working platform, manpower, equipment and machinery ect Besides our mentioned works, the good co-ordination with other contractor for related works like M&E contractor for embedded system inside RC structure Concreting is only allowed to start when the necessary requirements are met

Ready mix concrete is transported to site by truck mixer 6 m3 Slump is required to check before placing To avoid non-stopped supplying contractor prepares 01 concrete pumps, SANY HBT60C-1413DIII-50m3- per hour-140m pump up to location and 01 stand by one SANY HBT60C-1413DIII in good working condition and ready to support if required Contractor intend to fix 3 piping system per block at convenient location for pumping in which 2 piping system using often and other one is stand by one Placing concrete for beam is done first then slab later, which is divided in every 3-4 m section each Waiting time

is not exceeding 3 hours During concreting requires monitoring the deflection of formwork

or unforeseeable thing may have (if any) to treat in time Placing in pile is not allowed to avoid over loaded problem causing formwork may be collapsed Curing concrete is maintained by clean water during 01 week

3.4 Beam and slab concrete of transmission floor (1 st floor):

This is a special block of beam and slab structure having big cross-section of beam (H*B=2500*2400) and slab thickness is 1000 This type of structure is quite different in working sequence