Construction method statement

TEMPORARY WORKS PLAN CONTENT: I/ Site preparation and temporary facilities Ii/ material and equipment III/ execution drawings for temporary works (as attached) I- Site preparation and temporary facilities: Soon after receiving a letter of award, the Contractor will immediately prepare to set up the construction site, promptly contact with local Authorities and Public Transportation Service and related Services for construction permission for worker and machine The temporary facilities are including but not limited to the followings according to layout drawings for temporary facilities: Grading, compacting, sewage and drainage, cleaning, safety board Temporary site road will be setup to ensure site traffic is thorough, conventional and safe Temporary site road with sufficient notice boards to be maintained during whole construction period During the construction time the Contractor will maintain and spraying water for restriction of dust and keeping environment Temporary water supply: The point of water supply should be supplied by the Owner The Contractor may sign the contract with local supplier for delivery water by tanker to site if necessary The delivered water will be contained in the temporary water tank on site and supplying for construction execution, curing, fire prevention and living through pumping and piping system In case this source is insufficient, the Contractor plans to drill well Site drainage and dewatering: Site drainage shall be maintained for protection of the Work Site and ensure the clean environment Storm water will be caught to manholes and sum pit before connected to the local existing drainage system Temporary power supply: The point of power supply should be from the Owner The Contractor shall liaise with local Electricity Company for getting permission of using power resource of them In addition, the Contractor will provide standby generators: 30KVA for construction 1/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc activities in case of shortage at each project The temporary lighting and power system on site is setup above with rubber electric cables and connected to power points through break and relay for safety Electrical net for site will be made of double-insulated cable (3x35+1x16) and stable hang above ground, each electrical device must have circuit breaker and safety grounded Temporary telephone system: Temporary wireless telephone system will be setup at site offices after completion of temporary buildings Temporary Building: - - - The Contractor Site Office (12mx9.8m) will be provided adequately with required furniture and equipment during the whole construction period Gather yard for steel structure shall be established at site area with compacted stone base Storage and yard of materials Storage of materials will be established with two kinds: indoor storage for storing of cement, rebar, tools ….and outside yard for storing of sand, gravel, brick … Because construction area is very large so difficult for establishing temporary fence We will protect material and equipment by using cover storage with lock, increase numer of guarder and guard houses for sercurity insurance, restriction of the construction activities and avoid inconvenience to other part of project Cleaned water tank, portable WC will be made Temporary accommodation area for workers will be located out of project site (made of prefabricaed structure or house rental) The camp for worker will be kept clean, ventilated, dry and good looking Ii- Preparation of material and equipment: Material: * Material specification: The Contractor will strictly follow Material Specification instructed by the Owner and Consultant Construction materials mainly shall be from local source - Sand, gravel and aggregate shall be based on technical specification (3550-8310-SP0005) and taken from local area, - Cement is from Vicem, Nghison ect hase to be met technical requirement that stipulated on 3550-8310-SP-0005… 2/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Reinforcing bar is from Hoa Phat, VIS ect…that conforming to project specification - Ready mixed concrete should be from PVV batching plant or other at the local area matching the Owner requirement Contractor will conform to the specification and design, any changes will be reported to the Employer for approval * Exploitation, transportation, preservation: - Contractor will establish a material and equipment team under QS department for the purpose of material procurement Materials delivered to site will be preserved carefully in cover area above the ground or in a good manner Equipment and formworks Construction equipment will be mobilized to site according to the progress of works Scaffolds and Formwork preparation: Contractor plans to use steel prefabricated formwork for main structures combining with wooden supports and plank for small and non-standard structure form Kind of scaffolds should follow manufacturer’s specification and calculation for each kind of works Before making scaffolds system for slab Contractor will prepare calculation to submit to the Consultant for approval 3/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc WORK METHODOLOGY CONTENT: I/ work Methodology statement Survey and benchmarks works Piling works Earth works Formwork Reinforcement Concrete work STRUCTURAL STEEL AND ROOF WORK Waterproofing and test Masonry, plastering and other finishing works 10 Plumbing and electrical work 11 conclusion II/ execution drawings (as attached) 4/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc I/ work Methodology statement Survey and benchmarks works: 1.1 Survey works: The Employer already carried out soil investigations for each site Contractor will take additional steps necessary for familiarization with the site condition The site investigation work shall be carried out using modern methods, equipment under supervision of a qualified engineer The Contractor will study and investigate the entire site In place of excavation, workers shall use manual investigation method by pressing under the ground and through that getting information about underground obstacles to find an appropriate solution 1.2 Benchmark works: In parallel with survey works, Contractor will deploy the benchmark works of wooden piles Main benchmark will be made by concrete pile outside the building so they will not interfere to any works during execution of this building Make offsets m from two direction of this benchmark and they will be used for control of the Benchmarks during the construction works pilling works GENERAL: Generally, the pile driving procedure will be accordance with the order as follows: PREPARATION THE PILE DRIVING EXECUTION Preparation for implements: - Site plan - Equipment, pile driving machine - The staff on site To carry out works as follows: - The order of execution - Checking allowable tolerances - Forms Including steps as follows: HANDING OVER 5/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Preliminary handing over before driving - Detailed handing over after completion - Forms COMPLETION Checking the following conditions: - The pile set - The cut off level - The general ordinate of pile gridline - The other load tests PREPARATION WORKS: Preparation of site plan: - Site plan should be cleaned preliminarily such as excavating brush, stump, removing obstructions, thin mud from site area Checking the underground systems informed by the Client or strange obstructions, bomb… - To carry out improvement soil at the site to reach the necessary strength to bear the live load of facilities, equipment, temporary static load of pile layers on the site plan To construct a public road system, pile storage and traffic signboard out of the site area - To carry out constructing the inner road so that it is not blood, enough strength in case of executing in the rain season - Constructing sewage system for site area, hygiene equipment, electricity, water serving for shift of executive and workers Preparation for execution equipment: The list of the execution equipment serving for work as follows: No Machinery & Equipment Capacity Quantity 01 DH62 diasel pile driving rig 50 –75 Ton 05 02 Pile hammer 6.0 Ton 05 03 Pile hammer 4.5 Ton 02 04 Chain wheel crane 30 Ton 01 05 Chain wheel crane 50 Ton 01 06 Excavator (when necessary) 0.5 m3 02 6/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc 07 Welding machine 300 – 1000 A 01 08 Truck-trailer (when moving) 30 Ton 06 - If it is necessary to add the execution equipment to complete the pile driving work, that will be further mobilized - All machinery and equipment, which have certificate of calibration, will be mobilized to site However, mobilization of automatic pile driving will be priority - The leading pipe system of pile driving will be checked before driving The slipping system must be insured in two directions - Checking vibration degree of whole rigs and hammers in the during of pile driving, if exceeding and not ensuring settlement while driving that must be repaired or replaced a bigger one - Pile lifting equipment, cable, puly, winch that must be checked carefully before using - Welding machines must be checked carefully at points of joint especially input voltage to ensure the safe of electricity and fire - Surveying equipment must have certification of calibration of The Testing Center Staff organization: - Construction teams must submit the list of qualification workers, supervisors working on the site and site organization diagram to Supervising Consultant or Client for approval - Also, they must submit the range of duties, rights and connected way for each personnel working on the site - The Contractor must submit the certificates of Supervisors, Welders, Crane Drivers and pile driving drivers, etc… to The Supervising Consultant or the Client for approval before commencing any works PILE DRIVING WORK: The order of pile driving: Pile maintaining at site: All storage piles at site keep in good condition carefully Be specific to comply with regulations as follows: Piles comply with number of layers exactly (non exceeded 03 layers) Supporters must be put in the correct handling positions marked on pile body Piles are not put on the ground directly which maybe generate particular stresses to crack or break pile to effect on quality of pile Absolutely not put any heavy objects on the pile body as well as preventing to hit beside of pile body 7/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Do not put piles which have the differ lengths together While transporting, loading to truck-trailer as well as unloading storage or installing into locations, hooks and cables must be good; and when workers wear the cable into handling points, they should be careful to prevent slipping and breaking The previous fabrication piles should be driven first, the next pile will be driven later unless having the other requirements from the Client or the Supervising Consultant Maintaining methods at site must be done strictly, any violations must be penalized adequately to ensure the strictness and safety for all works Surveying of pile location: The work will be done immediately after completion of site plan preparation and having full of designed pile drawings They includes works as follows: Locating standard level is obtained from the National standard level It should be done and handed-over with Supervising Consultant and the Client because it will be base on cutting pile head after completion Locating points of co-ordinate standard in piling location gridline Locating points of pile is obtained from locations of points of co-ordinate standard The surveying work are done by theodolites and checked in two perpendicular directions, also constructing fixed intermediate survey-marker to perhaps check promptly the coordinate system of pile driving Pile driving: Preparation works before driving pile: Gathering full of pile quantity of adjacent driven pile positions Checking the number of pile, diameter, length, pile location, hammer type, drop height of hammer to record on pile driven record sheet Marking each 25cm for final piece of combination pile nos to determine the depth of driven pile Preparation equipment use for recording pile set such as pile set recording form, drawing pencil and supporters etc… If execution at area recorded to have obstructers, it should be removed out which is near the nature ground level or boring in advance if it is more deeper Prepared dolly is soft wood such as fir or plywood with 5-10cm thickness The wood dolly is used one time for a driven pile only, it is not used for the next pile although it still be in good status Should use cover and dolly suitable with pile cross section The slits between pile hip to each of the edge of cover should not exceed 1cm 8/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Pile driving execution: Piles are installed in the rig and positions by chain-wheel crane or wheel crane with capacity of 40-50 Ton or winch system of rig directly While handling, should pay attention to points of wearing hook is necessary exactitude, especially dragging pile into the rig at one point must be complied with Engineer’s instructions Piles are checked the vertical degree in two perpendicular directions by theodolites and it is careful continuously during driving procedure Diesel hammer of 2.5 Ton is used to drive 0.30x0.30 square pile, 4.5 Ton, 6.0 Ton to Φ500 spun pile, 6.0 Ton, 6.5 Ton to Φ600 spun pile (when trial driving if stratum is soft, it can be used the 4.5 Ton hammer to drive Φ600 spun pile) When jointing pile, the joint is the welding joint, height and width welding is done as shown in design detailed pile drawing and welding rod is type of ELEPHANT KR-3000 On the other hand, alignment of under piece must be line to the upper piece and centric axis of under piece is line to the upper piece When driving, follow and check frequently as well as counting the blows of 100cm penetration length to record in the pile driven record sheet When driving to the final meters, it has to count the number of blows of 25cm penetration length When pile meets the required level, stop driving and record by mean of pencil, supporter and paper of 10 blows continuously To bearing pile, the ultimate bearing capacity of driven pile will confirm by Hiley’s formula to define the pile set, rebound and height of hammer About 5-20 first piles, it is researched the pile set carefully to adjust the power’s hammer for suitability and determine the penetration length of pile so that combination method of pile is save and the execution time is shorten In case of reaching the designed penetration depth but the pile set is not or contrary is to stop driving pile and inform to Surveying Consultant or The Client immediately to decide whether continuously or not to prevent damaging pile body To friction piles, driving pile will be stopped when pile tip reach the designed level or bearing capacity of pile is over the designed bearing capacity While pile driving procedure, if any strange phenomenon are happened is to stop to inform to the Engineer to be instructed treatment method complied with 6.1-6.4 clauses below Checking: Checking before pile driving procedure: Checking slits on the pile body, bending degree, perpendicular degree to site plan 9/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Checking certification of calibration of rig and pile driving equipment whether met allowable calibration criterions Checking pile installation position suitable for design While pile driving procedure, perpendicular of pile need to be checked frequently in two directions as well as center of both of piece when jointing, especially appeared deformations Allowable tolerances: The declination of pile position to drawing must be un-exceeded 75mm to the horizontal of pile gridline and 75mm to the along of pile gridline Axial direction deviation of pile that compares with axial direction of pile shown in drawing will not exceed 2% Tolerances of installation will be specified as follows: Position : +/- 75mm Inclination; verticality +/-0.02 (1:50) The driven pile is not complying with the above tolerances that will be refused Treatment methods will be discussed to Consultant Engineer or proposed methods must be approved by the Client Formatted Forms: Formatted forms recording the result of execution pile driving to each pile will be attached in Appendix Form 1: Inspection and Test Plan Form 2: Pile Driving Report Form 3: Pile Driven Record HANDING-OVER WORK: Preliminary handing-over: Piles transported to site will be checked preliminarily by means of tape ruler and visuality to basic data as follows: The length of pile: +50mm, -10mm The width and quantity of cracks Checking the clean pile body Handing-over after pile driving: The completion driven piles will be checked the bearing capacity of pile by Hiley’s formula as follows: ef * Wr * H * (Wr + n * Wp ) Qu = ( s + * c) * (Wr + Wp ) 10/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc 5.11 Not allow operators to leave the pile in suspended situation during temporary stopping 5.12 Forbid to carry out in strong wind weather 5.13 Forbid to carry out in dim light, foggy or lack of light SOME OF CAUTIONS: While pile driving procedure, some of phenomena often happen and treatment methods are to be done: Pile was reached to the required pile set before reaching the designed depth: in this case, the driving team should stop driving and re-drive after 03-07 days from the stopping day to prevent pretending refusal by gathering stresses phenomena at pile tip or hard obstructers If the pile set still be not changed then, it should be to inform to Supervising Consultant or the Client to approve whether accepted or not Pile reached at the designed depth before reaching the required pile set: in this case, it should be to inform to Supervising Consultant or the Client immediately to consider treatment methods or connect the second pile to drive the pile until reaching the required pile set or stopping to drive to cancel it and adding the other Pile is broken at the pile head in driving: if happened, it should be to inform to Supervising Consultant or the Client and Manufacturer to consider the grade of destroyed pile head together If the pile head is damage slightly such as appearing the slits around the hook or peeling off concrete outside the pile head, it is done to cut off damage part of 0.3-0.5m from the end of slits, then pasted the end plate other by Epoxy glue and it is driven continuously after 30 minutes If the pile head is damaged strictly such as collapsing on side or the length of breaking completion concrete to expose reinforcements are large, at that time, it should be approved by Supervising Consultant or the Client to permit to treat as the above or add the pile other Pile is driven over the above allowable tolerances in 3.2 clause: adding the pile other or enlarging the pile cap if Supervising Consultant or the Client approved earth works * Sequence and method of excavation works: - The Contractor will receive and protect established benchmarks in the manner approved by the Engineer Grading work will be carried out to the line and levels shown on the drawings 12/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Use excavator machine for excavation approximately to the design level, combining with the workers trimming Special care should be taken during excavating near the RC pile - Obstacles, voids and excess excavation will be treated in the way indicated in the specification and executed under prior approval of the Engineer Commonly excess excavation will be fill with lean concrete or selected hard aggregates * Access planning and traffic movement in and around the site: - Appoint signal persons for regulating traffic of dump trucks transporting surplus soil and mud out of the site - Maintain access road in a good condition during earthwork * The de-watering system, discharge point: - Excavation will be kept free from water at all times, contract sumps with suitable size and keep the water table below the bottom level of foundation by using of water pump with big capacity A team shall be appointed specially in charge of maintaining discharge water system on site This team will consist of pump operators and labors The team will stay 24 hour per day in the rainy days for immediately action * Disposal and store of excavated material: - Truck for transportation of soil should be covered with sheet * Backfilling work: - Imported sand shall be selected capable of being compacted to the bearing capacity required - Part of sand from excavation work will be re-used for backfilling Quantity of excavated sand will be stored near backfilled area - Backfill work will be start only after inspection and approval of the Engineer for underground work Backfill with selected materials from excavation (sand), cut out soft areas before starting - Backfill simultaneously on each side of the foundation, protect the waterproofing work under strict supervision of the Engineer - Compact sand by layer being less than 30 cm by hand or hand rammer, care will be taken during compaction to avoid fracture or harm to the underground structures and piping works - Check the foundation elevation by the leveling machine, preparation for lean concrete 13/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc form work General: - The Contractor shall supervise fabrication and construction of the formwork periodically during executing and getting approval from Engineer before concrete pouring This approval however does not relief the Contractor of any responsibilities to conform strictly to the tender specification and construction drawings - Contractors shall always submit shop drawings for approval of any structure before commences Shop drawing will be made by an Engineer specialist of formwork showing all detail information about installation of form Pre-fabrication of form and form finish: - The Contractor will prefabricate form panel at the workshop of the company Truck transports forms to site and store it in a form prefabrication area at site - Surface of the form shall be plywood or metal wherever approved by the Engineer Construction of the formwork: Construction of the formwork will be done strictly in accordance with the specification and approved by Engineer The Contractor will make emphasis to the following points: - Form shall be constructed watertight, properly tight together and braced to maintain position and to prevent bulging, deflection and pillowing between form supports - Location and installation method of kicker and clean out will be submitted to Engineer for approval - Embedded part shall be installed in accordance with the manufacture’s recommendations ensuring items are not disturbed during concrete placement Installation will not hinder striking of form and loss of grout Form openings shall be provided where required for pipes, conduits, sleeves etc Attention should be paid to wall formwork: - Wall of water tank must be supported sufficiently to bear the pressure of concrete during compaction - Side formwork of foundation beams shall be removed after days Touch up and curing of concrete will be same as above mentioned in the general part Attention should be paid to slab and beam formwork: Beam and slab are monolithic concrete structure and requires accuracy and quality works described in the following steps: 14/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Install scaffolding system “PAL” and “H” shape (the type common scaffold in Viet Nam) with jack bolts on the bottom for adjusting elevation and comfortable removal of form work Head of beam support will be installed, while at the bottom end adjust jack bolt to the designed elevation A wood squares with size 250x250x30 mm installed on the bottom of scaffold to prevent subsidence of scaffold system - Install wooden bar with size 80x120 mm (or steel shape following Contractor’s calculation) at top of scaffold then pre-fabricated form for slab and bottom of beam, fix bracing angle and lock bolts for form work - Tie steel re-bars with concrete spacer blocks and steel chair - Supporting scaffolding and forms under slab beams and girders shall be remained in place until the required strength of the concrete has been obtained Construction joint: - Location of construction joint will be indicated in the designed drawing and being approved by the Engineer prior to concrete work - Water stop will be provided to construction joint of tank where water tightness is required following instruction of the Engineer Cleaning and coating of form: - Contractor will use SIKA agent “SEPAROL” for releasing of form under Specialist recommendations Re-use of form: - No form panel will be used more than times, clean and make good each time after using - The Contractor will mobilize good quality formwork for construction following instruction of the Engineer Removal of form: Removal of any form shall not be permitted until the concrete has developed sufficient strength to support itself and resist surface damage and any stress arising during the construction period Scaffolds for slab and beam are removed when minimum strength of concrete reaches 90% of design strength, a re-shoring is required for the long span beams Addition the Contractors will always looking for professional opinion of Engineer before removal of form While removing form, Contractor will check the quality of concrete on surface and touch up by mortar indicated in the specification in case of uneven finish Other serious case of “honeycomb” will be informed to Engineer for solution, a special mixture of mortar with 15/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc chemical may be required Surface to be patched must be thoroughly cleaned and wetted to receive the patch reinforcement - All prefabricating work will be carried out in site workshop Equipment in workshop: - Re-bar cutter φ - φ 32 - Re-bar bender φ - φ 32 - Machine for straightening rounded re-bars - Electrical welding machines - All steel work such as industrial cleaning, bending radius, lapping, thickness of the concrete cover etc should be strictly followed the Specification, drawings and instructions of Engineers - Welding of reinforcement will be carried out only with prior approval of the Engineer, welding of deformed bar is restrained - All reinforcement, after having been fixing in the position, shall be inspected and approved by the Employer’s Representative before any concrete is placed Concrete works * Concrete pouring: - All preparation works such as cleaning, tools for casting should be done prior to concrete casting Concrete work can be performed only after getting the approval of Engineer for formwork, reinforcement - During the concrete work, plate or needle vibrators must be used all time, supervisors to manage and check the quality of concrete casting The maximum height of pouring is not higher than 1.5 m to prevent concrete segregation Contractor will pay attention to keep the bottom and top level of slab by the design (accuracy of 10mm) 16/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc * Curing: - After concrete has been placed, the concrete surface shall be cured during consecutive day keeping moist by sprinkling water or by other appropriate methods, and shall be prevented from direct sunlight, rapid drying and cold - As a rule, neither foot traffic nor load shall be permitted on concrete for at least 24 hours after placement However, under circumstances where foot traffic or placing of loads on freshly placed concrete becomes unavoidable, it shall be allowed only as instructed by the Engineer - Curing compound will be applied where required * Report: A diary of the concrete work shall be kept during a whole period of concrete works for the project This diary shall be submitted every working day to the Employer for examination and his signature The diary shall contain notes and records of the followings: - The names of the engineers who are responsible for different phases of concrete works and names of their assistants - The temperatures of air, water, cement, aggregates and concrete, together with the air humidity and type of weather - Deliveries to the site of concrete materials (quality, brand of cement, etc.) - Any special instructions given by the Employer - Inspection carried out, test performed and it’s results - Times of commencement and completion of the different parts of the concrete works, and times of erection and striking of the forms - Quality of cement, fine and coarse aggregate, admixture used for each section of works, number and kind of test samples taken on these ingredients and water * Concrete testing procedures: - The Contractor must fully arrange tools, sample form for testing slump of concrete, the number of Cylinder sample forms and place for curing A group of samples for every 30 m3 (or as directed by Engineer) will be tested by days and 28 days (and stored) according to the specification The minimum number of test cylinder to be prepaired from each sample shall be six, three for testing at age days and three at age 28 days Contractor will conform to the specification and design, any changes will be reported to the Employer for approval 17/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc STRUCTURAL STEEL AND ROOF WORK 7.1 Fabrication, inspection and approval of structural steel at workshop: Fabrication, inspection and approval of structural steel at workshop shall comply with Specification - Installation of structural steel must comply with design drawings - Next step shall be carried out only when the assembly, welding and bolting have been completed - Mechanization to transportation, assembly and installation - During installation, special care shall be paid to the protection of bolt threads from rusts and damages - Unloading, maintenance, transportation of structural members shall guarantee no damage to painting, no free throwing during unloading - Other specific requirements shall comply with consultant instructions as well as requirements of Project technical specification: Structural steel – Fabrication , installation, inspection and approval - technical requirements 7.2 Erection: * Preparation works: - Checking and surveying the as-built concrete structure with position of embedded anchor bolts, if there are any mistake exceeding the limit as specified the Contractor should propose the appropriate repairing method for approval by Engineer - Checking the delivery docket - Arrangement steel structure members following of type, dimension in right position as directed by Engineer All the members should be laid on the base plate to avoid wet weather and for loading and unloading easily All the roof sheet will be covered and placed as slope above from ground floor Arrangement of steel roof sheet 18/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc * Selection of erection crane: The Contractor will use the wheel-tyre crane for erecting works * Process of erection: Erection of steel trusses: - - Preparation • Because of the steel trusses have large span we will provide the supporting frame (supporting frame is designed and fabricated appropriately for each particular trusses span) Using two numbers of 30 tons crane with appropriate specification for erection of steel structure • Preparation of scaffolding, ladder, safety belt and others tools and equipment at the erecting location Erection • The half trusses will be erected from outside • Placing the bracing to trusses with length is depended on trusses dimension • Lifting the trusses up to position by crane • Workers will adjust the hanging trusses to the position by temporary bracing rope Primely tightening by bolts at first and of trusses to the embedded plate and anchor bolts then continue with the remain Notes: After completion of erection of trusses together with purlin, bracing and the temporary bracing will be taken out when the purlin were stably installed at least 1/4 of numbers of pulin Erection of purlin: - Preparation: Checking the dimensions, classified types Arrangement of structure to position - Erection: Transport and remove structure o position by lifting crane or manpower and purlin will be installed and tightened with bolts  Method of bolt tightening: Using of high tension rubbing bolts for the bolt connection Prior to erection the entire connected surface to be cleaned out to ensure specified tighten force The bolt tightening will be carried out by machine and then checked by force measured wrench under the standard for checking of high tension bolt These checking results will be recorded in the erection log sheet 19/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Roof Covering: - Preparation: Checking dimensions, types for laying the roof sheet in the right position Transportation and removal of roof sheet to high position by lifting system or manpower - Installation of roof sheet: Proceeding after completion of purlin erection • Laying the first sheet follow the dimension as shown on drawing and using the aliment wire for locating the last sheet • Start laying from roof edge and building sides to finish at roof capping The roof capping plate to be installed in the right position without slit Attention should be paid to: - - Regularly marking out the positions of drilling hole by chalk for fixing bolt accurately By that way we can avoid leakage occurred by drilling mistake and can get the nice outside face Cleaning debris from drilling by brush on the entire laid roof sheet when finish of each working shift Fixing the screw on the higher rib Tightening bolts and screws with appropriate force Using the instruction of the manufacture to install doors, windows and other accessories Final inspection: Upon completion of erection work the final inspection for all the members and accessories to be carried out as follows: - Checking the position and connection of bracing members - Checking all the position and tighten of bolts - Checking the cleaning of roof sheet, roof gutter - Checking the screws - Checking the tightness of roof cover sheet - Cleaning out upon completion of works Safety during execution of the erection works: - All workers and staffs take part in execution on site should be disseminated safety regulation and armed sufficiently safety measures No alcohol or other stimulants in working time 20/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - People working above should wear safety belt which to be anchored to the stable structure No working under the loaded crane boom Scaffolding, ladder, bracing rope etc to be firm and stable Removing of crane hook after the structure was stably erected Walking on the roof along position of purlin It is not allow the worker stand and walk on the edges No walking on the skylight Stop working above in raining weather Only start working again after checking all safety conditions Proceeding the lining works at the same time for ensure safety for men and building Tool and equipment for each teamwork: Lifting equipment: - Propping bar 6m and 12m length: 20nos - Cable with difference length and sizes - Steel wire for temporary bracing (8 nos at least) - Rope for pulling up by manpower Electric equipment: - Welding machine (2nos) - Drilling machine (2nos) - Screw driver (2nos) - Electrical break (1no) - Hand concrete drilling machine Hand tools: - Wrench 12 - Philip screw driver - Right and left hand scissors - Clinch-nail gun (2nos) - Large hammer (2nos) - Steel saw (2nos) - Timber saw (2nos) - Water-level pipe and plumb bob - Measuring tape - Knight and hook - Chisel - Oxygen bottle 21/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Safety belt Broom and brush Folding-ladder (2nos) waterproofing and test - A waterproofing admixture shall be used only if the Employer has given this prior approval in writing - To ensure water tightness at a construction joint of underwater structure a waterstop shall be provided at joint between bottom slab & wall, joint along the wall Waterstops shall be installed when approved by the Engineer - Water tank shall be test loaded for waterproof checking when concrete gained sufficient strength - Before application of bituminous coating the surface of concrete shall be throughout cleaned from all dust and loose materials - The procedure of applying any waterproofing materials should be strictly in accordance with the manufacturer’s instruction - Labors for waterproofing works are in a specialized team, never use other workers for this works masonry, plastering and other finishing works * Brick work: - In order to keep the even surface of the wall for whole length of Building, Contractor shall use a theodolite to mark center line of wall & two sides of the wall to the surface of concrete columns before brick laying Procedures of work is as follows: - Installing scaffold system when the height of brick wall is > 1,5 m - Laying wooden beams 80x120 for supporting working decks - Placing working deck - When starting brickwork, two wires shall be placed parallel to keep the wall surface even - Watering before laying to keep the humidity of wall and reinforce its joint - Wall to be fully filled with mortar, joints in different layers are not in the same position, 220 mm (or 200mm) thick wall must be laid in longitudinal and in transversal During brick laying work use theodolite for marking and plumb, aluminum ruler to check plumpness of the wall surface - All the voids and opening will be made during brick laying to avoid hacking work afterward 22/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc - Cure of brick wall shall be followed specification * Plastering work: - Wall of tank shall be remained exposed (no plastering) Internal surface of sludge reservoir and sludge thickener shall be treated with waterproofing chemical as instructed by the Employer Plastering work shall be as followings: - Start plastering work for one area only after completed installation of door, window frame, waterproofing, piping system and electrical wiring - Scaffolds and working deck is done in the same way as the brickwork or using the remained scaffolds from brickwork - The wall surface will be cleaned and watering with water before plastering - For large wall, its surface will be divided into smaller square (1.8x1.8 m) by control spacers of fresh mortar - Thickness of plastering layer will be from 1,5 to cm; the plastering surface will not have any cracks, mortar yielding and other defects Edges of doors, windows to the wall must be straight, parallel and sharp - Plastered wall will be cured by water spraying after 24h in accordance with specifications depend on the weather conditions) * Other finishing works: It will be constructed under instruction of Engineer and strictly following specification of tender document and manufacturer’s recommendation 10 Plumbing and electrical work 10.1 Piping works: Pipe GI: There are methods of connecting pipes a Welding method: + Check tools (welder and cutting machine, power supply source, CO fire extinguishers) + Check labour safety instruments + Clean pipes + Check execution drawings, pipe installation position + Transport pipes to execution location and put pipes into holder or plat surface + Avoid scraps going to pipes when cutting and sharping + Lay pipe to be connected on a pwell prepared flat surface (Fig and 4) 23/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc + After checking safety, start connecting pipes + If the pipe is too long, anti-expansion soft joints should be used + Clean iron rust by using iron brush before and after welding + Seal ends of pipes with covers, test pressure (invite consultants/supervisors/supervisore to inspect) + Check pipe height (according to execution drawing), direct pipes in straight direction (invite consultants to inspect) (See figures 1.5 and 1.6) + Check pressure according to technical requirements (invite consultants to inspect) + Prepare acceptance document (invite consultants to inspect) + Seal pipe ends tightly with nylon or glue and sticking plaster + Tighten pipe clamp (Refer figure 1.6) + Equip pipe with paints and anti- rust paints for welded joints b Threaded connection: + Check thread device and thread tool + Cut, sharpen and polish pipes + Wire or spread sealant glue and sticking plaster before connecting + Connect pipes (Refer figure 1b) + Other operation steps are in sequences as connecting by welding method PPR, HDPE pipes: Connection between pipes and pipes, pipes and fittings are required having a specialized welder (thermal welding) supplying 220V power source to weld pipe at 260oC Steps are as follows: + Check positions (Refer execution drawings) + Check execution tools and place pipes into plane + After thermal treatment sucess, withdraw pipes and fittings out of the device then compress pipes with fittings, hold tightly in regulated time PVC pipes: + Transport pipes to location to be installed + Check installation position (Refer execution drawing) + Clean pipes and fittings need to connect + Cut, sharpen and polish pipes (Refer figure 3.1) 10.2 Electrical works: Lighting, Plugs, switches Preparation: Submit detailed installation drawings 24/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Submit sample materials if required 25/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc Installation: - Mark with luminescent ink or ink with color - Install concealed box, mask, etc - Pull cables and electric wires Works after installation - Measure the electric isolation and check the cable circuitry before connecting cables - Register measured values in issued forms - Clean and cover tightly switchboards, equipment right after works 11 conclusion - During period of execution, the Contractor will pay attention to the application of advanced technologies; encourage of initiatives and improvement to keep quality & progress of work -The Contractor will make a detail-working schedule (weekly & monthly) based on the general schedule - Solutions will be applicable when delay happens: + Increasing number of equipment and machines + Increasing manpower + Working overtime - In case of force majeure, the Contractor will discuss with the Employer to get the best solution 26/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc ... 3/storage1/vhost/convert.123doc.vn/data_temp/document/hlm1527444922-2445943-15274449228134/hlm1527444922.doc WORK METHODOLOGY CONTENT: I/ work Methodology statement Survey and benchmarks works Piling works Earth works Formwork Reinforcement... obtained Construction joint: - Location of construction joint will be indicated in the designed drawing and being approved by the Engineer prior to concrete work - Water stop will be provided to construction. .. modern methods, equipment under supervision of a qualified engineer The Contractor will study and investigate the entire site In place of excavation, workers shall use manual investigation method