c«ng ty cæ phçn x©y l¾p ®iön i

- The Contractor shall take full responsibility for making agreements on temporary landborrowing, temporary roads and compensation for construction work with managingagencies and local a

CHAPTER I BASES FOR PROJECT FORMULATION AND IMPLEMENTATION

Construction method of this project is prepared on the following bases:

Applicable standards:

2 National Technical Codes for Installation of Power Network: QCVN QTĐ-7:2009BCT enclosed with the Decision No 54/2008/QĐ-BCT dated December 30, 2008

3 Quality management in installating & building works - Basic

4 Acceptance of construction quality of construction works TCXDVN 371: 2006

6 Handover of construction work – Basic principles TCVN 5640: 1991

8 Procedures for formulation of the building organization

design and the building work design National regulations on

construction and acceptance

TCVN 4252: 1988

9 Regulations on construction supervision and acceptance of Overhead power linewith voltage up to 500kV – Enclosed with Decision No 908/QD-EVN dated May

28, 2008 of Vietnam Electricity

10 Foundation works – Construction and acceptance TCXD 9361: 2012

11 Technical safety regulations in construction work TCVN 5308: 1991

12 Earthwork – Specifications for construction and acceptance TCVN 4447: 2012

13 Monlithic concrete and reinforced concrete structures

-Specifications for construction and acceptance

TCVN 4453:1995

14 Concrete and reinforced concrete structures TCVN 5574: 2012

15 Concrete – Requriements on natural moisture curing TCVN8828: 2012

16 Aggregates for concrete and motar Technical requirements TCVN 7570: 2006

17 Aggregates for concrete and motar Test methods TCVN 7572: 2006

18 Heavy weight concrete - Method for determination of

20 Heavy weight concrete compounds - Slump test TCVN 3106: 1993

21 Specifications for Portland cement TCVN 2682: 2009

TCVN 6260: 2009

22 Cements – Standards for testing cement TCVN 4029: 1995

23 Water for mixing Concrete and Mortar - Technical

Specification

TCXDVN 302: 2004

25 Bored pile – specifications for construction and acceptance TCVN 9395: 2012

26 Hot-rolled steel for reinforcement of concrete TCVN 1651: 2008

No Name of Codes and Standards Symbol

27 Carbon steel for normal concrete structure Steel grades and

technical requirements

TCVN1765: 1975

28 Tensile and bending test of reinforcement TCVN 197: 2002;

TCVN 198: 1985

29 Reinforcement in concrete Welding arc TCXD 227: 1999

30 Covered electrodes for manual arc welding of mild steel and

low alloy steel - Symbol dimension and general technical

requirement

TCVN 3223: 2000

31 Covered electrodes for manual arc welding of mild steel and

low alloy steel - Test method

TCVN 3909: 2000

33 Specifications for steel shape and plate JISG3101,

3106/3192

OCT8509-72;TCVN 1656: 1993

SS540, S490

TCVN1896: 1976;TCVN 1889: 1976;TCVN 1897: 1976;

37 Steel structure – Fabrication, assembly and acceptance –

40 Procedures for electrical safety issued by Vietnam Electricity enclosed withDecision No 1157/QD0EVN dated December 19, 2014 of the General Director ofVietnam Electricity

41 Regulations on acceptance of bolt linked steel structure for voltage class up to500kV enclosed with Decision No 82/QĐ-EVN-QLXD-TĐ dated 07/01/2003 ofEVN

42 Regulations on hot dipped galvanized steel of Vietnam Electricity enclosed withDecision No 2982/QĐ-EVN-TĐ dated 10/09/2003

43 Applicable regulations on occupational safety, urban traffic safety, environmentalprotection and other relevant documents

And some other relevant regulations and standards

The Bidding document prepared by the Hanoi Power Development Project Management

Board (Hanoi DPMB) – Hanoi Power Corporation on “Package ADB-HNPC-TCTD-P01:

Design, providing, installing and operating underground cable network of 110kV - project:Underground cable network of 110kV Thanh Cong – Thuong Dinh – Project: Development of Hanoi and Ho Chi Minh Electric Grids”.

Sub-Construction experiences on electrical works of Power Industry Sub-Construction JointStock Company

CHAPTER II GENERAL INFORMATION ON THE PROJECT

1.1 110kV Underground cable network

- Voltage class: 110kV

- Number of circuits: 2

- Beginning terminal: 110kV Busway of Thanh Cong 220kV transformer station

- End terminal: Circuit 1: 110 kV Busbar of Existing Thuong Dinh 110kV Transformer

station

Circuit 2: 110kV Busway of Expanded Thuong Dinh 110kVTransformer station

- Length: 3.728 km

- Type of cable: Single phase underground cable Cu/XLPE-1x1200mm2-110kV

- Earthing: Using TT Grounding system

- Installation of cable joint and cable ends must be compliant with techncial standards ofcable

- Optical cable: using non-metal optical cable (NMOC)

+ Method of cable placing:

- The section burried directly on the ground, pressure cable is covered by HDPE D200conduit and protected by concrete blocks Optical cable is placed in HDPE D50 tube

- In the scope of transformer station, cable is placed on the rack of internal cable trench

1.2 Expanded area of Thanh Cong 220kV Transformer station

- Thanh Cong 220kV Transformer station is located in the end of Dang Tien DongStreet, Dong Da District, Hanoi City under management and operation of PowerTransmission Company No.1 – National Power Transmission Corporation

- Thanh Cong 220kV Transformer station is a in-house GIS transformer station (Gasinsulated switchgears by SF6 gas) with permanent scope including 02 transformers of220/110/22kV-250MVA and 03 transformers of 110/22/10kV-63MVA

- In this period, Thanh Cong 220kV Transformer station has been making design andconstruction investment: 01 220/110/22kV-250MVA transformer, 02 110/22/10kV-63MVAtransformers and 22kV-25MVAr resistance band

- Scope and scale of expanded items of Thanh Cong 220kV Transformer station is toinstall 02 GIS dividers for Thuong Dinh 110kV Transformer station along with solutions ofconstruction, control, protection, contact information and power self-supply, etc., for 02 linedividers

2 Description of cable route:

+ Thanh Cong – Thuong Dinh 100kV underground cable route starts from 110kVBusway of Thanh Cong 220kV Transformer station (located in Dong Da District, HanoiCity) and ends at 110kV Busbar of Thuong Dinh 100kV Transformer station (located inThanh Xuan District, Hanoi City) The underground cable route goes over some streets:

+ Section designed in Hoang Cau – Thai Thinh 2: From Thanh Cong 220kVTransformer station, going over the right side of road bed towards Hoang Cau – Thai Thinh

2 In this section, the cable route goes parrallel with Ha Dong – Thanh Cong 110kV, 220kVunderground cable network

+ Section designed in Nguyen Ngoc Vu – new Khuong Dinh: After crossing to the end

of Thai Thinh 2, the cable route goes across Lang Street, crossing To Lich River at position

of Moc bridge, then the route turns left and goes cross Nguyen Ngoc Vu to Nguyen TraiStreet, then to new Khuong Dinh Street In this section, the cable goes cross the road bedalong the left sidewalk

+ Section designed Khuong Dinh Street: To the end of new Khuong Dinh, the cablecontinues to Khuong Dinh Street, and in this section, the cable goes cross the road bed alongthe right sidewalk, then turns to Lane 282 to Thuong Dinh 110kV Transformer station.+ Section designed in expanded Thuong Dinh 110kV Transformer station: In theexpanded Thuong Dinh 110kV Transformer station, the cable route is placed on the cabletrench of the Transformer station Circuit No.2 will connect to E09 compartment ofexpanded station Circuit No.1 continues to go inside the cable trench to the existing stationand connect to E04 compartment

+ These are main streets with high populuation and vehicle desity with the peak hourslasting from 6.00am to 22pm These streets are quite narrow

+ The cable route has big angles in turning positions: Thanh Cong 220kV Transformerstation – Hoang Cau, Lang – Moc Bridge – Nguyen Ngoc Vu, and the beginning of ThuongDinh 110kV Transformer station

Some obstacles crossing with cable route:

- Crossing with water supply, drainage conduitlines and power lines: 24 times

- Road across : 1 time

- Intersection : 4 times

III DESCRIPTION OF KEY WORKS OF THE PACKAGE

1 This package include the following items:

- Provision of materials and supplies to the package

- Construction of cable trench, joining tunnel and cable hangers crossing To Lich River

- Placement of HDPE conduit

- Inspection, acceptance and handover of the completed work

2 Description of key works of the Package

2.1 Construction work

- The Contractor shall take full responsibility for making agreements on temporary landborrowing, temporary roads and compensation for construction work with managingagencies and local authorities based on the Contractor’s measures.

- To carry out leveling work, cable trench, cable joint tunnel , cable hanger, installation

of HDPE conduit, accessories, earthings and other related works as shown in the designdocument and specifications of bidding document

2.2 Supply of materials, equipment and transportation of materials to the site foot.

- All HDPE piple, building materials and cable hanger crossing Nhue River, cablesignal board, cable signal pole, grounding copper wire along the route are supplied by theContractor

- The Contractor shall be responsible for transporting materials and equipment to thesite Cost of transport shall be included in the Contractor’s breakdown quotation

IV CONSTRUCTION SEQUENCES

1, To receive design document provided by the Employer

2, To read and check the design document

3, To prepare bill of quantity

4, To make concrete tests and steel tests

5, To assign works to construction team

6, To make plan for manufacture and contracts for purchase of materials and supplies

7, Gia công cốt thép, tiếp địa To fabricate reinforcement and earthing work

8, To organize working team for receiving land mark, foundation position with theEmployer and Design Consultant

9, To organize working team for inspection of route, distances and centre linepositioning, direction stake, protection stake, route as-buitl and making comparison withdesign scheme

10, To set up management board office, material warehouse and yards

11, To prepare and submit construction method to the Employer

12, To settle outstanding issues on temporary roads, material yards, etc.,

13, To make application for cutting road permit and prepare traffic safety assurancemeasures

14, To execute underground cable trench, dig cable joint tunnel, manholes, cable hangerfoundation crossing rivers

15, To install cable hanger crossing rivers, underground cable earthing and cable rack

16, To make acceptance and handover to put the work into operation

CHAPTER III

SITE PREPARATION

I SITE ORGANIZATION:

For execution of “Package ADB-HNPC-TCTD-P01: Design, providing, installing and

operating underground cable network of 110kV - Sub-project:Underground cable network

of 110kV Thanh Cong – Thuong Dinh – Project: Development of Hanoi and Ho Chi Minh Electric Grids”, the Contractor shall set up a Site Management Board and

the Site Manager, on behalf of the Contractor shall manage construction work

The Site Management Board office is located in Dong Da District (near constructionlocation of 110kV underground cable route) and equipped full modern equipment andfacilities for production management and control as well as making acceptance between theContractor, the Employer’s Representative, the Design consultance and managing agencies

1 Site Organization chart:

CONTRACTOR: POWER INDUSTRY

CONSTRUCTION JOINT STOCK COMPANY

ADMINISTRATIVE OFFICE, STORE KEEPER, SECURITY

GUARD

SUPERVISION OF TECHNICAL QUALITY AND SAFETY

SUPPLY OF MATERIALS, MECHANICAL CONSTRUCTION AND SURVEY WORK

CONSTRUCTION TEAM NO.3

2 Notes to Site organization chart

The Contractor shall sign the Construction work with Hanoi DPMB The Company’sDirector shall be responsible to the Government and the Employer for quality, progress andHSE of the work

* Responsibility for organization and implementation

- The Director and functional departments & boards shall communicate with theEmployer’s departments & boards during construction work To direct and assign specifictasks of each work item to Departments of Planning, Supplies, Technical, LaborOrganization, Finance Accounting to assist the Site Management Board to complete thework in accordance with the construction schedule, technical requirements and absolutelyoccupational safety as well as to perform management of construction quality

- The Director shall direct to set up the Site Management Board and assign specifictasks to 04 construction teams

* Site Management Board

Organization and responsibilities of the Site Management Board

The Site Management Board shall be under direction and management of the Directorand shall report Director all construction activities (once per week)

The Site Management Board shall make direct communication with A TechnicalSupervisor, Design consultant, Land Acquisition Board members of the Employer, localauthorities and other relevant agencies related to construction work

The Site Management Board shall directly receive and maintain materials for supply toconstruction teams

The Site Management Baord shall directly guide, instruct, supervise in techniques, HSEand shall assign and push construction teams to accelerate the construction work

+ To take part in weekly meeting with the Employer in the site

+ To make partial acceptance of completed work for shifting to next construction stageand acceptance for completed work

The Site Management Board’s responsibilities are to direct construction teams tocomplete the work in accordance with construction schedule, technical requirements,quality, safety and environmental hygiene after completion of the work

Key personnel of Site Management Board.

+ Mr Tran Viet Thuong – Construction engineer

+ Mr Le Duc Tan – Electrical engineer

- Environmental Controller Team: Mr Tran Thong Phan – Environmental technologyengineer with more than 05 years in construction work and environmental supervision shall

be responsible for daily supervising the Environmental operation (EO) of the Contractor

- Safety and occupational hygiene: Mr Do Danh Hung, a staff attended and granted theHSE training certificate in construction works shall be in charge of supervising safetyoperations during construction work

- Bộ phận Kế hoạch, vật tư: gồm 01 người Planning & Supplies Team: 01 people

- Occupational safety – industrial hygiene: 01 people

- Administrative and medical team: 01 people

* Construction teams:

In order to complete the work in accordance with the construction quality, progress andoccupational safety – industrial hygiene, the Contractor shall arrange 03 construction teams(02 construction teams for underground cable route and 01 for construction of station) with

10 – 15 workers and 01 technical engineer for each team Total technical workers takingpart in the project is 50 skilled ones with grade 4/7 and upwards (as for some commonworks which are not required workmanship, we shall sign short-term contracts with localcommon labor with the number of 10 – 15 people subject to construction progress)

Construction team No 1&2: to execute cable trench, building cable trench, joint tunnel,manhole, cable hanger crossing rivers, earthing

Construction tem No.2: To execute renovation work of Thanh Cong station

Tasks of construction teams

To execute complete works from digging and backfilling cable trench, installation ofcable rack, construction of joint tunnel, bending tunnel, cable hanger crossing river, eathing;

to execute renovation work in Thanh Cong 220kV station completely and take responsbilityfor making acceptance with the Employer untill completion of work handover

To be under direction and assignment of construction work and to receive, use andpreserve materials and equipment from the Site Management Board To prepare and submitweekly construction schedule to the Site Management Board

To direct, organize and execute construction work in accordance with the approveddesign drawings, procedures and regulations as well as according to construction scheduleand requirements on quality, occupational safety and industrial hygiene

To take care the living standards of staff and employees working in the site

To prepare daily report on all construction activities to the Site Management Board.The construction teams shall be under direction and assignment of construction workand to receive, use and preserve materials and equipment from the Site Management Board

To prepare and submit construction schedule and to receive supplies and materials to theSite Management Board.

The Site Management Board shall frequently coordinate, contact and communicatedirectly in the Site with the Employer, Design consultant, local authorities and other relatedagencies for timely settlement of outstanding issues for not causing any adverse impact onthe approved schedule

II SITE PREPARATION:

1 To set up Site Management Board, material warehouses and yards.

- The site office is located in Dong Da District, Hanoi City (near the construcitonlocation of 110kV underground cable route): (48m2 accomodation + 36m2 working office) :84m2

+ Office equipment: Tables & chairs, computers, printer, photocopy machine,telephone, Fax machine

+ Covered warehouses: Wooden frame with steel sheet roof, wooden walls and highslab in 40cm higher than the ground, 100m2 wide used for storing cable ends, valve arrester,cement, steel, accessories, etc

+ Open-warehouse: used for storing cable hanger, cable, sand, stone, etc., with area of600m2

+ Accomodation for construction teams:

The maximum number of workers working in the site is 60 people, so the camp areashould be: 50 people x4m2 = 200 m2

The Contractor shall make temporary camps or hire houses near the project area forstaff and employees of construction teams for easy travel and working in the site

2 Preparation of electricity and water for construction:

- Water: we shall directly communicate with local provider for arrangement of waterused for construction work and living conditions and equip 01 water pump for eachconstruction team

- Electricity: The Contractor shall contact with electricity management unit in thelocaity to buy power for construction work and living conditions and also equip 01generator for each construction team for construction work

3 Preparation of construction plan:

Upon receipt of construction plan from the Employer, the Contractor shall make allrequired procedures before construction work, in particular:

- To assign 02 topo engineers and 04 common workers to check centerline andelevations, distances, levels, route length, joint tunnel location, cable hanger, etc., Then, to

prepare and submit as-built documents to the Employer and upon the Employer’s consent,

we shall proceed with construction work

- We shall work with Environment Department and other adjacent areas to askpermission for transport of wastes to the disposal area All our building material transportvehicles must be covered by canvas to prevent materials from falling in the road

- Safety and industrial hygiene supervisor of the Site Management Board shallfrequently supervise and remind workers to not throw building wastes to causeenvironmental pollution and landscapes of the adjacent areas of construction plan

4 Preparation of materials and supplies:

The materials provided by the Contractor must be compliant with requirements onquality, types and quantity as specified in the construction tender document and shopdrawings

- Cement bags shall be put layer by layer with the maximum height of 7 bags in proof and ventilated place Cement shall be used in the principle of first-in, first-out In 15days after placing cement bags in the warehouse but not being used yet, our workers shallmove the bottom bags into the top and vice versa

water-4.2 Sand, stone:

- Sand and stone used to mix concrete is purchased locally near the site withoutimpurities under TCVN-1771-87 standard We shall contact local suppliers in the projectarea and neighboring areas, and shall take sand samples to a competent agency with legalstatus (or designated by the Employer) to make intensity test and concrete mix design TheContractor shall submit these test results to the Employer and shall sign contracts withsuppliers upon the Employer’s approval and permission for use

- The sand and stone yards must be arranged next to the mixer and must be dry, cleanwith canvas to separate sand and stones from the ground

4.3 Water:

Water taken from wells or water source (clean water) in locality must not be dirtwithout impurities and chemicals to mix and cure concrete Water must be transported to thesite by water tank trucks

4.4 Building steel:

Upon study and review of design drawings and preparation of bill of quantitiesincluding types, diameters, quantities, characteristics in accordance with the Biddingdocument

We shall contact with steel supplier and inspect steel in meter, visual and takingdelivery sheet of steel lot Then, to take steel samples used in the work to make test in anapproved laboratory (or appointed by the Employer) in physico-mechanical properties inaccordance with TCVN 197:1966 and TCVN 198:1966

Upon obtaining satisfactory test results, the Contractor shall send documents enclosedwith these results to the Employer and we shall sign economic contracts for supply of steelonly in accordance with dimensions, diameters, quantities, material sources as agreed withsteel lot certificates and steel delivery schedule with steel supplier upon the Employer’sconsent

- The Contractor shall present mill certificate, and quality certificate, test results, dipped galvanized steel certificate, welding arc ultrasonic results for all galvanized steels.All materials must be tested in intensity, physic-mechanical properties, etc., inaccordance with technical standards and submit results to the Employer for approval, then toput into use in the work

hot-5 Preparation of building machinery/ equipment:

The Contractor shall mobilize and meet full quantity of vehicles, building equipment forconstructionw work in accordance with the construction schedule agreed with the Employer,types, quantities, quality of machinery/ equipment included in the list of machinery/equipment and working tools (Please refer to the enclosed list of construction machinery/equipment)

6 Preparation of construction documents:

Prior to construction work, the Contractor shall prepare the following documents:

- Design document, construction method, shop drawings prepared by the Designconsultant approved by competent authorities, procedures and regulations on electricalworks and technical standards applicable to construction and acceptance andrecommendation letter to work in localities and other relevant agencies, etc

- Construction method approved the Employer

- HSE Cards of staff and employees

- Health examination results for staff & employees

- Application for temporary residence and labor declaration

- Preparation of high-voltage working sheet and power cut registration schedule

- Construction diary

- Detailed construction schedule

- Procedures for cutting roads for construction

- Detailed construction method for major items

- Acceptance forms and minutes under the Decree No 15/2013/ND-CP dated Feb 06,

2013 of the Government on quality management of construction work; Circular No.10/2013/TT-BXD dated 25/7/2013 detailing some articles of construction qualitymanagement; Circular No 09/2014/TT-BXD dated 10/07/2014 amending andsupplementing some articles of Circulars providing guidance on Decree No 15/2013/NĐ-

CP and other forms specified by the Employer

CHAPTER IV

CONSTRUCTION METHOD

I CONSTRUCTION PROGRESS SCHEDULE

In order to timely mobilize construction machinery/ equipment, materials andmanpower for construction work, and also to rationally implement work items, theContractor shall commit to perform the package in the maximum period of 9 months, fromthe date of handover of construction site by the Employer The construction sequences and

duration of Package ADB-HNPC-TCTD-P01: Design, providing, installing and operating

underground cable network of 110kV - Sub-project:Underground cable network of 110kV Thanh Cong – Thuong Dinh – Project: Development of Hanoi and Ho Chi Minh Electr e

Horizontal diagram method

2 Total construction performance period is 200 days

ic Grids” shall be compliant with the construction progress schedule:

(Please see the enclosed construction progress schedule)

Explanation of Construction progress schedule:

1 The construction progress schedule is prepared under th

: 10 Maximum number of workers: 50

3 Total direct workers:

- Minimum number of workers

4 Expression of project performance process:

- To arrange 03 construction teams with 50 skilled workers, grade 4//7 and upward toperform the work items

1 Purposes:

We shall prepare the construction progress schedule to actively perform the constructionwork for production of schedule of use of materials, manpower and time in the rationalmanner for purpose of completion of the work under the approved schedule

In order to give proper directions to construction teams, time and features of work, theContractor shall arrange manpower, materials and finance to meet the construction progressschedule agreed with the Employer

2 Content:

Some major content given as below:

- The construction progress schedule is prepared on the basis of requirements of theprocuring entity on the bidder’s of capacity, and detaled construction method of each workitem which has been studied and prepared to stabilize the work as well as mobilization ofmanpower, material, machinery/ equipment in the proper manner The constructionsequence must be shown on the binding relationship between these works

- To determine demands for manpower as well as machinery used in the works It isrequired to show phases, stages and determine the necessary construction activities Suchconstruction progress schedule is shown on use of manpower, machinery/ equipment andmaterials in each phase

- To be the bases for calculation of warehouses, yards and camps to set up overallconstruction plan

- The construction progress schedule is to combine flexibly between construction workand electrical installation and other finishing works to promptly put the work into use

- The construction progress schedule is used as a solution for work balance, accordingly

to reach targets set up by the Site Management Board and to complete the overall schedule

of the work

- To allocate capital and work amount in cash under the construction phases and time ofperformance

II CONSTRUCTION METHOD

II.1 CONSTRUCTION OF CABLE JOINT TUNNEL AND CABLE TRENCH

1 Site handover

We shall set up a working team including Construction engineer, topo engineer and landacquisition staff to receive centerpoints and elevations of underground cable route from theEmployer and the Design consultant After determining centerpoints and elevations ofunderground cable route accurately, we shall carry out foundation positioning, cable tunnel,cable hanger foundation crossing rivers and cable trench according to the designeddimensions To drive red-paint stake 50x50x1000 to foundation center, and continue drivingprotection stakes with distance of 20m surrounding the pit and trench

2 Land acquisition.

After determination of cable route dimensions, we shall request the Land acquisitionboard under management of the Employer to work with the Land acquisition board atdistrict-level, commune/ ward-level and households, managing agencies who have damages(like Road management company, Greenery park company, Urban lighting company, etc.,and also based on the construction method (approved by the Employer), we shallcommunicate with the Land acquisition board at district-level, commune/ ward-level andhouseholds, managing agencies incurring damages to inspect and count trees and cropsgrown in the land area for construction work and way of transport of building materials andequipment, etc., then to make compensation to these household and agencies incurringdamages based on the compensation unit prices approved by Hanoi PC

As for sections which are required to cut and reimbursement of roads, pavements, weshall communicate with Hanoi Department of Transport and managing agencies to make

application for cutting road, and to prepare the plan for traffic safety assurance duringconstruction work.

In Hanoi urban area, it is very complex to carry out digging cable trenches, because it isrelated to a number of agencies and trafffic situation The foregoing has presented how toarrange construction corridor for easy construction and maximum avoidance of traffic jam

as well as construction safety assurance Prior to construction work, it is requried to markfully positions of other underground works, to set up fence and digging planning signalboard system (for locations near underground works) with separatly mechanical digging

It is required to make specific construction method for sections which used to be carriedout before (technical system, water supply and drainage, asphalt paving) to prevent fromcausing adverse effects And, it is also required to prepare specific construction method forsections which have never been carried out And all construction work must be compliant todesign so that all underground works must follow planning design

The Contractor may use square support to change the length by joining these togetherand fixing in steel nuts for the high-bearing walls and to use round support with threadtightened in the pit walls which are not required the high-bearing

Crushed stone, asphalt concrete and excavated soil shall be transported continuously tothe suburban After completion, these trenches shall be backfilled and reimbursedpavements and median strips in the original status

3 Detailed construction method:

3.1 Method statement of underground cable trench

a Digging cable trench:

* Mechanical and manual digging

- After receiving construction plan of underground cable route handed over by Party Aand design consultant, to carry out land clearance and digging trench for placing conduit

- As for trench sections cutting asphalt roads, concrete roads, prior to construction work,

we shall use machine to cut concrete along two sides of trench, then to break concrete layerand remove Due to high density of transport, we shall arrange safety barrier and assignsignal men to control traffic To minimize traffic jam, in these sections, we shall mostlywork in the night time and for cable trenches which have not backfilled yet after completion,

we shall use 1cm thick steel plates to cover for normal traffic We shall use U-shaped steel

or laser sheet pile to drive in both sides 2.6m thick, combining with bamboo to stabilize pitwalls In some narrow sections, excavated soil shall be transported to the disposal areaimmediately to prevent from traffic jams

- The digging sequences is from top to down, and excavated soil is removed to a sidewith 0.3m – 0.5m far away from the pit to avoid falling into the pit

- To level trench bottom according to design dimension in design depth

- To make acceptance of cable trench before placing conduit.

b) Placing conduit and backfilling cable trench

b1 As for cable trench designed in pavement and greenery area:

To place a black sand layer as a cable trench bottom layer To finally check the cablelength after completion of minutes of acceptance of complete work to shift to next stage

- To place HDPE conduit to match the cable roll length and joining points

- HDPE conduit shall be placed in each circuit: HDPE 200/9 is placed horizontallycorresponding to 2 ways, with their distance of 0.5m, distance between pipe center is 0.3mminimum

HDPE conduits must be placed straightly and evenly Pipe connection points must becompliant with design

- To make acceptance of conduit placing before backfill

- To backfill sand in layers and compact layer by layer to reach design thickness

- Dimensions of protective slabs must match dimensions of cable trenches and placed

on the black sand layer to protect mechanically the cable route

- To arrange 01 HDPE 50/3 for optical cable on concrete slabs in 500mm far away fromcable

- To backfill trenches and compact them, then to place underground cable signal band indesigned width of each cable trench in designed depth, then to backfill and compact, thenthe Contract shall reimburse in the original surface structure and make procedures forhandover and warranty with the department of transport and related agencies

- Backfill work must ensure the design requirements

To reimburse right after completion of a section Waste soil shall be transported todisposal area

b2 As for cable trench designed under the asphalt pavement:

After making acceptance of cable trench dimension:

- HDPE conduit shall be placed in each circuit: HDPE 200/9 is placed horizontallycorresponding to 2 ways, with their distance of 0.5m, distance between pipe center is 0.3mminimum and placed on concrete spacer

- To arrange 01 HDPE 50/3 for optical cable on concrete slabs in 500mm far away fromcable

- HDPE conduits must be placed straightly and evenly Pipe connection points must becompliant with design

- To make acceptance of conduit placing before backfill

- To backfill trenches and compact them, then to place underground cable signal band indesigned width of each cable trench in designed depth, then to backfill and compact, thenthe Contract shall reimburse in the original surface structure and make procedures forhandover and warranty with the department of transport and related agencies

Laser or shape steel piles or bamboo piles, length 2.6m

Sidewalk or road

- Backfill work must ensure the design requirements

To reimburse right after completion of a section Waste soil shall be transported todisposal area

ANTI – LANDSLIDE WHEN EXCAVATING CABLE TRENCH

Sidewalk or road

3.2 Statements of construction of connecting tunnels, manholes, tuunel trenches

After the Employer delivers the constructioon site and determines the location where weconstruct accurately

We use the theodolite to redefine the center line of cable trenches, cable connectingtunnels, bending tunnels and dimensions in accordance with the design

Cable connecting tunnels are structures whose dimensions are relatively large on thecable route Construction of cable connecting tunnels will face many complex problems,especially in urban area For cable connecting tunnels whose dimensions are large, it isnecessary to have appropriate traffic division measurs when constructing in these locations

In the urban area of the city, construction of the cable connecting tunnels shall becarefully planned and rigorous

All underground works shall be removed, if any, from the scope of connecting tunnelsbecause they are very sensitive locations on the cable route

In order to stabilize the wall of the pit, Lazsen piles should be driven 0.5m higher thanthe pavement, 1.5m deeper than the bottom of the pit The scope of pile driving shall be 0.5

m wider than the pit on the sides In each specific location, it can be adjusted in conformitywith the actuality in the fiel and detection of underground works The upper part isconvered with the iron metal plate whose height is 2m and straight at the edge of the pile

There will be many places on the entire route when digging for groundwater Preparethe method of placing pumps and the discharge line for the pumped water from theexcavated groove to up This should be especially noticeable in the urban area of the city

There must be a filter net to prevent the discharge of soil and mud from cloggingunderground culverts.

3.2.1: Construction of laser piles

a Prepare: Complete installation of 380V-125kW power supply and the layout of

construction machines, cranes

b Expected time for construction:

- For the pile pressing by the static machines, working hours are from 06:00 to 23:00

c Measure of pressing and drawing Larsen -4 piles by the method of static driving.

* Prepare:

- Gather the drivers, cranes and Larsen pile materials to the location of construction

- Construction equipment including:

+ Dedicated tire cranes:

* Brand: or 25-ton Kato

* Lifting capacity: 25 tons

*Country of origin: Japan + Static pile driver

* Brand: GIKEN KGK 130 - C4 Silent Pile.Giken 70 and Giken 80

* Pile end compressing force: 70 tons – 130 tons

* Country of origin: Japan

*Power supply: 380V-50KV

* Construction:

- We use one to 02 hydraulic pile drivers (with the specifications as mentioned above)

to construct the work under the shop drawing and cranes for compressing the piles moving

on the temporary roads

- Because the construction is intermittent, we shall arrange smoothly to avoidconstruction affecting ech other leading to delay of construction progress

- The verticality of Larsen pile has tolerance in the range of 0-1% and the end of thepile is tilt towards the exterior of the work The verticality of the pile in the process ofdriving is adjusted by the machine and we will use the plumb to determine the verticality ofthe pile

- The process of construction is presented by us in the drawing of pile wallconstruction method procedure (with detailed drawing as enclosed)

Step 1: The driver compresses the first pile to the specified depth

Step 2: The driver compresses the second pile and determine the bearing capacity of thepile

Step 3: Lift the body of the machine and stop at the location where the pile clamp is lowerthan the end of the pile

Step 4: After stabilizing, lift the pile driver

Step 5: Pull the pile clamp and the head of hammer forward, rotate the clamp from the right

to the left

Step 6: Adjust the head of the hammer to the pile to drive the pile gradually

- Note for driving work, it is necessary to adjust carefully so that the pile is not oblique

In the case of drawing the pile:

- When drawing the pile for doing the driving work, accordingly, location of the crane is fordrawing the pile, the contractor shall coordinate with the Employer, if it is impossible tostand in the internal road and the ring road 2, the Employer shall allow the contractor tobring the crane to the floor of the basement for removing the pile

- We, the contractor, propose: To remove the pile conveniently, it is recommended that theEmployer will excavate, construct the tunnel wall, remove the pile and then construct thebottom floor of the basement (To avoid that the crane shall move to the basement floorbreaking, damaging the floor)

a) The following tools for one construction team:

No

1 350-litter concrete mixer pc 1

2 2mm iron metal ( 2m x 3m ) Plate 10

3 Iron metal plate, thickness

15mm

Plate 5 Expect to place the road

4 250 – litter water tank Pc 2 Cast, cure concrete

6 Sand, stone measuring unit Pc 20

clangs

digging screws and etc

12 10 – litter water buckeet Pc 4

pipes

14 Stone, sand lining canvas m2 100

When the pit is excavated, we will use the tape and the machines to check thedimensions of the pit and correct according to the design dimensions as required.

Invite the technical supervisor of the Employer to take over the pit The parties sign theminutes of taking and work records, and then we will transfer to the next stage

The pit is always provided with the water pumps to ensure the pit is always dry forconstructing other works

c) Casting of lining concrete

Casting of lining concrete depends on the layout and construction conditions, it ispossible to use concrete mixed directly by the 350-litter mixer or commercial concrete to bepumped to the layotu of the foundation pit

After casting lining concrete, we will invite supervisor A to take over and with theconsent of the supervisor, we will tighten reinforcement and formworks

d) Installation of reinforcement and formworks

We will revview the design of reinforcement layout carefully

To prevent reinforcement from contacting with the lining concrete layer, we will useconcrete plates 50x50x50 to support reinforcement

After reinforement is tightened carefully, according to the design dimensions, we willplace and install formworks

The formworks used for the project are shape steel ones to ensure enough structures andart conditions

e) Placement of concrete

+ Concrete is mixed in place by 350-litter mixer

Aggregate of cement, sand, stones, water are calcualted according to the concreteaggregate for a mixing batch The steel unit is used to measure sand, stones, iron metalbucket is used to measure water

The 350-litter concrete mixer is used to mix concrete, when concrete gains the uniformsmoothness in the terms of colour within 02 minutes Concrete is placed in the guide troughwith tilt of 300 to the tunnel The vibrator with the vibrating end 60 is used to compact,after thickness of concrete is 20cm, we compact, distance of the next vibrator is 20cm Timefor compaction when stones and boam are not exposed on the surface of concrete issatisfied

Place and compact concrete as mentioned above until the concrete reaches dimensions

After placing concrete, we inspect the dimensions again

In the process of mixing, placing concrete, we will invite the technical supervisor A totake 02 samples of concrete from the mixing batch

Concrete samples (dimensions 150x150x150) are brought to the construction materialmeasurement agency for testing.

28-day concrete samples are brought for testing for concrete strength by us in theconstruction material testing center

After placing concrete, we will cure concrete by watering within 15 days

After 15 days as mentioned above, we remove the formworks of the entire concrete.Invite the technical supervisor of the Employer, the design supervisor to take theplacement of concrete

f) Waterproof work.

Due to requirements of waterproof work, waterproof work shall be done carefully andrequire high engineering As follows:

+Tunnel surface waterproof:

- Concrete shall be placed in a good way Concrete surface shall be uniform andsmooth

- Before applying with bitumen layer, clean

- Use the correct types of bitumen Apply with adequate layers Time for applying eachlayer shall be guaranteed

- When finishing applying, ensure to keep enough time and then backfill sand andtransfer the next construction step

+ Expansion joint waterproof:

Water stop is used for making expansion joint waterproof

The following notes shall be made when using this water stop:

- Used materials: Use the right types as required by the design (with specific origin)

- When installing for placing concrete for the first time: Shall be positioned carefullyand in a half of the width

- After placing the first layer of concrete, clean carefully (not damage water stop)

Concrete for the first time Water stop for the next concrete placement

Invite the technical supervisor to take over and then transfer to the next constructionstep.

- Fill soil for earthing

After the technical supervisor agree to transfer to the next construction step, we fill soilmanually Soil is filled for the trough with thickness of 300mm, we will water and compactsoil by the compactor After soil is filled with thickness of 200m, water, compact to reach tothe natural soil surface

- Earthing testing

After completing earthing work, we will use testing equipment: TEROMET 5000 tomeasure earthing resistance (if actual earthing resistance is higher than allowed designresistance, we report the Employer in writing for handling)

- Earthing acceptance.

After completing excavation, placement, filling, testing of earthing, we invite thetechnical supervisor and the design supervisor to take over and sign the minutes of earthingacceptance

After completing the tunnel, we will be as – built drawing of the foundaitoon, the cabletunnel earthing and then invite the technical supervisor A and design supervisor to takeover

Environmentall hygiene: After completing the works, we will gather and cleanconstruction machines and equipment, clean and return the construction site

h) Completion and acceptance of tunnel and earthing works:

- All consstruction works are recorded in the work records by the contractor with thewitness of the supervisor A suc as: date, soil excavation, casting of lining concrete,installation of formwork and reinforcment, placement of concrete, weather conditions, date

of concrete curing, excavation and placement of earthing rods

- After completinng installation and construction works of the cable tunnel, thetechnicians of the contractor shall inspect, measure data to prepare as-built drawing of thecable tunnel and earthing work

3.3 Construction of underground cable signalling pillar:

Together with filling soil, position locations of the underground cable signallin pillars,tighten reinforcement, install formworks for placing concrete of the pillars in place

- In each of 30m along the length of the route, place 01 underground cable signallingpillar

c Treatment of cross intersections of underground works

When excavating and placing the cables are in contact with the underground works,the following treatment measures are used:

- When the locations of the cable trenches are as deep as the upper surface of theunderground work, construct normally

- In the cross intersections with the drainage culvert system of the cable trench, excavatethe entire cable route, cables will be placed below the drainage culverts Distance from theculvert bottom to the protective concrete slabs for the cable route is at least 500mm

3.4 Construction of some cross intersections:

In the cross intersections with the road roads, cross the rivers, large drainage culvertsand etc, the contractor shall research, survey and prepare the method of construcitoncarefully Specially, for completed road sections, traffic division is made appropriately,construction is made at the night Renovate the pavement in order to ensure normalcirculation issues in the tommorow morning and then renovate the pavement in the originalcondition at the next nights

In the case of force majeure, it is impossible to complete at a night, install steel sheets inthe locations of trenches to solve temporary circulation for peope and light means fortravelling in this area, to avoid the traffic jam for surrounding areas Excavated soil shall betransported to the suburban area, clean the construction site to ensure temporary circulation

Excavate soil up to the construction landmark

Place protective concrete layer M200

Place HDPE pipes and position pipes

Place protective concrete M200 for covering HDPE pipes

Fill soil for the excavated pit and return the pavement in the original condition

*Treatment of cross intersection in the cross intersections:

Make layout of the construction site, appropriate traffic division Place signs andprohibition signs under the construction requirements

Cut the existing rod

Drive Larsen piles for anti – landslide

Excavate soil up to the construction landmark

Place bottom lining concrete and concrete protecting cables

Place HDPE pipes and position pipes

Place protective concrete for covering HDPE pipes

Remove lasen piles

Fill soil for the excavated pit and return the pavement in the original condition

3.5: Construction method of pavement returning

3.5.1 Bases for preparing the method of construction:

- Pursuant to the as-built route documents.

- Pursuant to specifications, construction structures, items and construction volume.

- Pursuant to detailed design of shop drawing of Thanh Cong – Thuong Dinh 110kV underground cables prepared by Power Engineering Consulting Joint Stock Company 4 and approved by the Employer.

- Pursuant to the capacity of machinery, equipment, human resources and construction ability and experience of similar works of the Contractor.

- Pursuant to abilities in providing materials of the partners which the contractor have long – term relationship and in the process of document preparation.

3.5.2 Organization of the construction site:

a Preparation of the construciton site:

After receiving the notice of site delivery of the contractor in charge of casting foundation base completion, within a day, the contractor will complete all preparation works: Organize the construction site, mobilize equipment, sign the contract of material supply, deliver the construction site and etc as follows:

- Establish the site managment board, manage the construction site and do the following works:

c Construction team and direction:

- Pursuant to the layout of pillar foudation locations, pursuant to the construction volume of major items, pursuant to supplies of materials , the contractor will establish 02 main construction teams

+ Team 1: Fill to return the road bed from the foundation bottom cost to cost – 0.6 compared to the existing pavement.

+ Team 2: Construct the pavement, traffic road marking

- Even though, two construction teams are established, the contractor coordinates and combinates with the construction forces, construction machines between the teams to construct many items at the same time in many locations in order to take advantage to reach synchronization of machines and qualifications of construciton forces.

- Construction direction: The contractor tends construction direction acocrding

to each foundation pit, two teams construct separately in 02 different adjacent locations to ensure to maximize human forces and machines For placing pavement bloc, construct each section continuously at the night.

1 Construction of traffic road :

1.1 Construction of road bed returning from the foundation bottom cost to cost – 0.6 (or cost – 0.5) compared to the existing pavement:

- Materials used for filling the foundation are medium – grained sand, volume ofmaterials calculated for gathering are adequate for plaving the foundation base k = 0.98according to the design length

- Correct the wall of the foundation pit in the square manner, clean the foundation pitbefore levelling for returning

- Fill each layer, thickness of each filling layer is from 25 to 30cm under theprocedures, pump water and use jack compactos in the joints where the rollers can notaccess, compact to reach required compaction, excavate each layer from 05-7cm beforefilling the next layer to reach the design altitude

1.2 Construction of ballast aggregate base and sub-base:

- Materials used for the foundation before putting in construction shall be sampled for tests to determine the required specifications such as: composition of the grain, largest dry weight, best moisture and etc to submit to the Employer for consideration, if approved, put into construction.

- Volume of materials are calculated fully fro placing the foundation base according to the design length with the compaction factor n = 1.42.

- Preparation of foundaiton pit: Before levelling the ballast aggregate layer, sand bed shall be repaired according to right altitute, smooth and compacted 02-03 times/point It shall be smooth without c onvex and concave points, water depositing, the road bed shall have enough geometric dimensions and its two sides shall be solid.

- Return of ballast aggregate layer on the route: Fill each layer from 15-20cm according to the procedures to reach altitude of the pavement to be completed like the old road structure.

- Prioritize to place materials in alternate ways on 2 sides of the foundation pit for covenience of levelling, transport of materials (because the foundation pit is in the middle of the median trip and one part is between 02 opposite lanes) Materials are placed in the blocks on the road bed (based on the construction progress and taking account into stratification of materials).

- The Contractor is responsible for ensuring the tranport on the route, absolutelly placing surplus materials indiscriminately leading to traffic jam.

+ Water while levelling and placing aggregate so that water is absorbed evenly.

- Because the foundation pit is narrow, it is impossible to use the grader, the team uses the excavator to place materials To avoid the stratification of mateirals, the technicians shall always follow the machine to supervise, guide the journey, speed of the machine and height of placing materials, and place the piles in order to control the altitude, use workers to grade to streighten after the machine grades basically The process of levelling and grading shall end before the materials are dry and bulk Surface of stones after grading shall be smooth and be corrugated without the stratification and unnecesssary travelling of the machine is limited.

- Construct in order in each foundation pit to ensure the transprot and limit traveling of the construction workers an machines many times.

- Roll, compact ballast aggregate.

a) For ballast aggregate base type II

+ Step 1 (Preliminary compaction): this stage accounts for 30 % of required compaction Use the jack compactor to compact basically from 3-4 times/point, it is necessary to offset convex and concave and repair the pavement evently After conducting required compaction for this stage, rest within 1-hours for the pavement

to be dry and then continue to compact at the next stage.

+ Step 2 (Tight compaction): This stage accounts for 70% of required compaction, use the jack compactor to compact materials with 20-25 times/point, compact until the pavement is smooth without the straits on the surface.

b) For ballast aggregate base type II

+ Step 1 (Preliminary compaction): this stage accounts for 30 % of required compaction Use the jack compactor to compact basically from 3-4 times/point, it is necessary to offset convex and concave and repair the pavement evently After conducting required compaction for this stage, rest within 1-hours for the pavement

to be dry and then continue to compact at the next stage.

+ Step 2 (Tight compaction): This stage accounts for 70% of required compaction, use the vibrating compactor (when vibriating gains 25T) to compact materials with 10-12 times/point, compact until the pavement is smooth without the straits on the surface.

- The process of rolling, compaction ends when required compaction is gained According to experience, when rolling, compaction reaches white point of the stone surface, without straits of roller tires, wavy in front of the roller tire straits and

if a stone is thrown and the roller goes cross such stone, such stone is broken, it is satisfied Avoid rolling many time leading to waste and breakage of the stone.

- In the process of construction, the technicians shall regularly inspect the dimensions of the pavement by the steel tape, measure, inspect altitude, carve to inspect thickness of the foundation, inspect the straightness by 3-m tape, inspect compactio by pouring sand, inspect composition of material aggregat by the standard sieve

- Cure of the ballast aggregate base: If after completing the ballast aggregate base, asphalt concrete is not made immediately, it is necessary to care under the following method: Every day, clean the sand, grits from the road bed If it is sunny, water 3 times a day, volume of water is 2-3l/m2 Because aggregate has composition whose is smaller than 1mm, in this process of compaction, rolling, it is exposed on the dry surface to form a dry sand layer on the surface of structure, water on the surface to stabilize this layer of small grains.

Inspection of quality:

- Inspect ballast aggregate before spreading.

+ Materials shall be transported to inspect the composition of the grain, ratio

of flat grain, plastic index and etc Take ballast aggregate samples on the container of the vehicle and the samples shall represent the entire aggregate.

+ When changing the stone mining, it is necessary to inspect all criteria as mentioned above, and test pilot compacion in the field.

+ In each 150m3 or 1 construction shift, inspect moisture of aggregate once.

- Inspect and take over after the process of construction:

+ Inspect compaction of each aggregate layer after compacting by pouring sand

in accordance with the procedure 22 TCN 13-79 In each 1500m2, take ramdomly 03 points or more according to the requirements of the consultant Factor K in fact shall

be more than or equal to design K.

+ Inspect thickness of filling layer: Combine with excavation of the pit to inspect compaction, we measure thickness of the placement layer by the steel tape Allowed tolerance is 5% but shall not exceed  10mm for the sub-base and  5mm for the base.

+ Inspect the foundation strength by the Benkelman lever.

+ Inspsect CBR index of the materials

+ Geometric dimensions and the flatness are inspected by the steel tape and 3m tape.

- Motorbikes and personnel.

- Unskilled workers : 15 people

- Skilled workers : 03 people

- Driver: : 09 people

1.3 Construction of asphalt concrete pavement

- Finish coarse grained asphalt concrete thickness 7cm and then construc fine grained asphalt concrete thickness 5cm Order of construction of 02 asphalt concrete layers includes the following steps:

- Before constructing asphalt concrete layer, the surface of ballast aggregate taken over shall be cleaned, dry, smooth and have horizonal slope according to the design If the the surface of the base is convex with potholes, repair and correct potholes and offset warping within at least 2-3 days.

- Materials used are 60/70 asphalt mixed with oil according to respective ratio or MC70 liquid asphalt as required in the bidding documents Use the air compressor, vacuum cleaner to clean the entire surface before constructing Use the asphalt spraying vehicle to place 01 asphalt layer as required.

- Application of tack coat: Volume of tack coat shall be applied when making asphalt concrete layer within 05-06 hours but not too early to avoid dust and rain water In the case of bad weather conditions or necessary traffic circulation, water within at least 04-05 hours Volume of asphalt 1.9kg/m2 is adequate under the technical requirements

* Hot asphalt concrete:

- In the process of construction, the contractor shall use asphalt concrete taken from the batching station The material sources are as follows: Crushed stones for production of asphalt concrete shall meet requirements of grain quality, strength Mechanical and physical standards of minernal powder shall meet regulations of original stone strength, volume emptiness and composition of the grain They shall ensure physical and mechanical characteristics, cleaniness, size of the grain and composition of the grain to product asphalt concrete

- Asphalt concrete used is 60/70 one taken in the locations according to A-4 to ensure enough quality requirements

- All materials used for this contract shall be inspected and approved before using.

* Production of asphalt concrete

- Before producing asphalt concrete, the contractor shall inspect including process of production, equipment and production technology of asphalt concrete to ensure the required quality of asphalt as provided Submit the consultant for approving the formular of mixing asphalt concrete for the package.

- The entire asphalt concrete station shall ensure good drainage and clean surface, therefore, materials can be clean and dry The yard of materials provided for the batching station shall be covered to avoid rainwater Mineral powder shall be stored in the dry and closed location.

- The procedure of asphalt concrete production shall be made accurately according to the instructions of equipment operation.

- In the asphalt concrete batching station, a group of technicians shall inspect the quality of materials, temperature of asphalt concrete, procedure of production technology and physical and mechanical characteristics of asphalt concrete mixture.

* Transport of asphalt concrete

- The dedicated vehicles will transport asphalt concrete produced in the batching station The container of the transport vehicle shall be clean, close at the bottom with high wall to avoid droping while transporting.

- Before placing asphalt concrete to the container of the vehicle, the contractor shall apply anti – sticking oil at the bottom of the container If transport is made in the bad weather, heavy wind conditions, the contractor shall provide the canvas to keep necessary temperature for asphalt concrete mixture.

- Before departing from the station, each vehicle shall be provided with the letter stating temperature, volume, quality of the mixture, departure time, destination and name of the driver.

- Before loading to the spreader, temperature of the mixture shall exceed 1200C,

if otherwise, such material shall be removed

* Placement of asphalt concrete

- The Contractor will not place asphalt concrete if it is rainy, windy heavily or there is a risk of rain.

- Clean the construction site, clean working place with the dust blower in combination with the manual hard brush.

- The contractor uses the asphalt watering vehicles and combinates with the asphalt contaienr to water asphalt under the requiremetns (based on each type of construction layer) This work is made according to the description The contractor shall comply with the diagram and work record strictly.

- Because area for placing asphalt concrete in the pillars is narrow, it is impossible to use the spreaders, the contractor shall place manually by use highly qualified technicians The contractor use iron bars to inspect thickness of the layer.

* Compaction of asphalt concrete

-After placing asphalt concrete, the contractor shall compact as follows:

- Use the roller in the process of asphalt concrete compaction Speed of the roller shall be below 4km/h for the steel wheeled rolleer and 10km/h for the tire roller + The first stage: 06-86 ton steel wheeled roller

+ Mediate stage: 16-ton tire roller

+ Final stage: 10-12-ton steel wheeled roller

- The process of rolling is divided into 03 steps:

+ The first rolling: 0-10 minutes

+ The second rolling: about 10-20 minutes

+ The final rolling: about 20-45 minutes

- Time of rolling increases in the winter and in the places where works are made manually.

- The roller tires are applied with anti-sticking oil regularly.

- The roller runs from the outer edge to the interior with the overlapping rolling width is 20-30cm.

- In the narrow loctions where the roller does not run, the handheld roller is used

to roll with the overlapping rolling ratio compared to rolling sign of 1.3.

- After two first light rolling times, use the normal method to inspect the horizontal slope, use 03-m tape to inspect the flatness For the parts which do not meet requirements, it is necessary to add hot asphalt concrete mixture immediately while the mixture on the lower base is still hot and is not compacted, the rolling process shall ensure required compaction factor.

- Compaction shall comply with strictly procedures and subject to supervision of the field supervisor.

*Main equipment, personnel for construction of asphalt concrete pavement

a Equipment

1- 80T/h asphalt concrete batching station: 01 station

5- 6-8-ton steel wheeled roller : 01 pc

6- 10-12-ton steel wheeled roller : 01 pc

12- Barriers, signs

b Personnel

- Skilled workers, driver : 10 people

1.4 Construction of backfilling for road structure inside the median trip; + Transport, gather soil level 3 to the location of construction, volume is

calculated in full for backfilling the structues inside the median trip according to the design thickness.

+ Fill each layer from 25-30cm under the procedures, use the jack compactor to reach required compaction.

+ Compact through two stages, preliminary and tight compaction, in the process

of the preliminary compaction, compact crosss 3-4 times/point and offset convex and concave points Make tight compaction until required compaction is gained.

+ Filling height is from cost -0.8 (or cost -0.3) until the cost of compledted pavement based on the locations of the foundation pit which the contractor fills for returning.

1.5.Installation of curbs in the median strip:

+ Gather materials, personnel, motorbikes to the location of construction.

+ Cut the asphalt concrete pavement to adjust the curb so that the medium strip

is not broken or folded in any location.

+ The contractor use the personnel to excavate the frame manually to install curbs.

+ Transport waste to the specified location.

+ Inspect altitude, vertical and horizontal center line and dimensions of the exvavated pit.

+ Mark the altitude and marking pile for placing concrete in the scope of the pit + Place gold sand.

+ Mix asphalt concrete stone 1x2 grade M150# and level concrete into each 10cm lauyer manually for linining the bottom.

+ Install the curbs for returning the hard medium strip.

+ Adjust the curbs, plater the circuit by the cement mortar grade M75#

1.6 Organization of transport:

a Pavement marking paint

+ Do not paint when it is raining or wet or in the opinion of the Consultant, inappropriate conditions for conducting the work Paint should not be applied when the pavement is wet or dirty, or while the pavement has sufficient heat to cause blistering and pitting on the paint surface.

+ The contractor uses the paint spraying machine to paint the pavement In narrow locations, a bristle brush is required Only use circular bristle brushes or oval brushes with a width not exceeding 150mm for painting.

+ The requirements of the paint work is that the paint surface must be shiny, straight lines, long, wide enough and not cracked At night, the paint should reflect light The thickness of the paint layer is guaranteed as prescribed.

II.2 CONSTRUCTION OF THE CABLE BRIDGE:

In the package, a cable section from point D13 to D14: the route goes on the cablebridge cross To Lich river

The cable bridge is made

1 Construction of cable bridge abutment:

After the Employer has handed over the milestone, altitude of cable bridge abutment,

we request the site clearance committee of the Employer to carry out the procedures withthe managing agencies (such as road and river way management companyf or To Lich riverbased on the method of construction (approved by the Employer), we are in charge of thelicensing agencies to issue construction permits and make plans to ensure traffic safetyduring the construction process

1.2 Survey of the work

Survey plays a very important role, it helps construction accruate in the shape andgeometric dimensions of the work, ensures the verticality, tilt of the structure, determine theright location of center line axis of the works, the components and technical systems,pipelines, eliminate errors for the construction work The survey work must comply withTCVN 3972-85

Locate the work: After receiving the delivery of the layout from Party A, landmarkand marking of the area Based on the positioning layout drawing, measurements are made

by the machine

Locate the position and altitude  0.000 of the items based on the total area layout,then make a written confirmation with the project management unit on the basis of the factthat the designer is responsible for the technical solutions of the position, altitude  0.000.Position the work in the scope of soil according to the design

The work shall be made of at least two major landmarks, the markers shall be at least

3 meters away from the edge of the work When constructing based on the landmark,measure in details the positioning axises of the housing

1.3 Driving the piles of the abutment foundation:

Driving the pile shall comply with standards: TCVN 160: 1987: Geotechnical survey forthe design and construction of foundation; TCXD 88: 1982: Pile - field test method; TCXD205: 1998: Pile foundation - Design standards; TCXDVN 286: 2003: Driving and presingpile - Standards of construction and acceptance and etc and other relevant standards andnorms

- The contractor plans to select Binh Duong Concrete Products and MachineryCompany Limited, which specializes in casting piles and driving piles as a partner to supplyprefabricated concrete piles and pile driving for the contractor

- Based on design documents, geological survey of the work and construction methods

of the contractor

- The contractor chooses the method of construction for pile foundation using the piledrivers, the contractor drives the piles in advance and then opens the foundation, therefore,the foundation shall be compacted to create the layout of construction before driving thepiles.

1.3.1 Preparation:

a Preparation of construction area:

+ The pile area must be outside the pile driving area, road from the pile area to the piledriving location must be flat, not rough, concave

+ Piles must have been marked for the center line for convenence of adjusting and etcwhen driving the piles

+ Remove piles that do not meet the technical requirements

+ Prepare full of technical reports of geological survey, static results and etc

+ Position and mark the foundation of the work

b.Construction equipment

* Pile driver

The pile drivers must have certificates, machine records issued by the manufacturer andchecked by the competent authorities for the technical characteristics of the equipment For hydraulic pile driver, the following technical specifications are required:

+ Oil pumping flow

+ Maximum oil pumping pressure

+ Piston bottom area

+ Effective stroke of the piston

+ The quality inspection sheet of pressure gauges and pressure relief valves issued bythe competent authority

Pile drivers selected for using in the work must meet the following requirements:

+ The maximum driving force of equipment shall not be less than 1.4 times ofmaximum pressure (Pep)max which affects the pile set by the design

+ Driving force of equipment must ensure to affect along the pile axis when driving theend or evenly on the sides of the pile when driving

+ The driving process does not cause horizontal impact on the pile

+ Motion of piston or hoist must be consistent and control the speed of pile driving + The pressure gauge must be in conformity with the measuring range

Pile driver must have a valve to keep the pressure when shutting down

+ Pile driver must ensure operating conditions in accordance with the regulations onlabor safety during the construction

The maximum measured pressure value of the gauge does not exceed two times of thepressure measured during pile driving Only about 0.7 - 0.8 of maximum capacity of thedevice should be mobilized

* Selection of the pile driver

- Section of pile: 25  25 (cm) each length of section 6.0 (m)

- Load bearing capacity of pile: P = 20 (KN) = 20 (T)

- To ensure that the pile is driven to the design depth, the driving force of the machinemust satisfy the condition: P min driving > 1.5  20 = 30 (T).

- We choose the hydraulic driver with the largest driving capacity is: Pdriving = 45 (T)

- Counterbalance weight of each side:

Pdriving > P min driving / 2 = 30/ 2 = 15 (T)

- Use concrete blocks of 1.0  1.0  2.0 (m) with a weight of 5 (T) as a counterweight,each side of the truss is placed with 5 blocks of concrete weighing 25 (T)

1.3.2.Preparation:

Prepare the construction site, clean and level the obstacles

Transport concrete piles to the construction site For concrete piles, please note:Permissible warping of coupling steel ring is not greater than 1% compared to the planeperpendicular to shaft of the pile The concrete surface of the pile should be flat The shaft

of the pile shall pass through the center line and perpendicular to two pile sections Concreteplane of the pile end and plane containing steel ring edges must be the same Only concreteplane which is parallel and overhanging steel edges not exceeding 1 mm is acceptable

- In the case of soil subsidence, timber must be lined down in advance to ensure the base

to be stable and horizontal during driving the pile

- Lift to instal the base frame to the correct design location

-Load counterpart on the base frame

- Lift to install the backet into the base frame, position accurately and adjust so that thedriving bracket is vertical

b Pile driving process:

Step 1: Drive the first pile C1, lift to install pile into the driving bracket, adjust the pile

end to the right design position and adjust pile in the vertical manner

The verticality of the first pile significantly affects the verticality of the entire pile,therefore, the first pile C1 must be carefully erected, aligned so that the axis of C1 coincideswith the axis of the jack cross the pile positioning location Eccentricity is not more than 1cm

Upper end of C1 must be fastened to the guide bar of the chassis If the machine does nothave a guide bar, the bottom of the jack (or piston head) must have a guide bar Then, thethe pile end must be tightly exposed to them

When t two sides are tangent to the side of the pile C1, control the valve to graduallyincrease pressure In first few seconds, pressure increases evenly, so that the pile C1 isgradually driven into the ground at a speed of no more than 1 cm / s

When it is founded for the inclination, stop, align again

Step2: Drive to design depth (drive intermediate pile C2):

When the first pile C1 is driven down to the design depth, the intermediate pile C2 isinstalled and driven

Examine two ends of pile C2, repair to be flat

Check the pile connector details and prepare the welding machine

Install C2 into the driving position Align so that the shaft line of C2 coincides withaxis of the jack and C1 Tilt of C2 does not exceed 1% Before and after welding, check theverticality of the pile by the spirit level Apply the pile with the force creating the contact sothat the pressure on the contact surface is about 3 - 4 KG / cm2 and then weld to connect thepile in accordance with the design

Drive pile C2 Increase driving pressure gradually so that the driver has enough time

to create sufficient driving force and the resistance of soil at the pile end to move the pile

At the beginning, C2 goes deep into the ground with a speed of no more than 1 cm /s

When C2 moves uniformly, the pile moves with the speed of no more than 2 cm / s When the driving force is suddenly increased, the pile end is in contact with hardersoil (or localized object), need to decrease driving speed to make the pile more capable ofpenetrating into the ground (or to examine the object for treatment) and keep the pressurenot to exceed the maximum allowable value

During the process of pile driving, the balance weight should be added to the chassistogether with the driving force increase process As required, the counterweight on thechassis coincides with the process of driving force increase The counterweight mustincrease by 1.5 times of driving force Because the pile consists of many sections, therefore,when each pile is driven, the pile should be connected by lifting the mobile frame of thedriving bracke, lifting and erecting the next setion to the driving bracket

Requirements for pile welding:

- The axis of the pile is connected with the compression method

- The concrete surface at two pile ends must be in close contact with each other, in case ,contact is not close, take measures to closely contact

- Size of welding line must be guaranteed according to the design

- Welding line connecting the piles must be consistent on all four sides of the pile according

to the design

- The surface of the contacts must be flat, with no errors of less than 1% and wihout seams

Step 3: Sound driving, when driving the last pile (4th section) to the ground, lift and install

core pile (steel) to the end of the pile and continue to drive the pile core to the pile end to thedesign depth This core pile will be pulled up to continue for another pile

Step 4: After driving a pile, slide driving bracket system on the base to the next position to

continue to drive During pile driving on the first foundation, use the crane to lift the secondbase at the second foundation pit

After driving a foundation, move the driving bracket system to the second base placed in thesecond foundation pit Then, lift counterweight from the base 1 to base 2

Finishing driving a pile:

The pile is recognized as driven when two following conditions are met:

+ The pile length shall be driven deeply in the ground not less than the shortest lengthprescribed by the design

+ Driving force at the last moment must reach the design value specified on the depth ofpenetration which is greater than three times of the he diameter or edge of the pile Withinthat range, the crossing velocity does not exceed 1 cm / s

In case two conditions as mentioned above are not met, report the Employer and designagency for handling When necessary, make additional soil survey, tests to have the basisfor treatment conclusion

The pile is too more tilt as regulated (larger than 1%), driving the pile is unfinished due toencountering objects of sand, abnormal clay, broken pile and etc, which must be treated byremoving and re-driving or driving additional pile (as specified by the designer)

Use appropriate drilling method to destroy objects, go through the sand, hard clay and etc When the driving force has reached the design value but the pile can not go downanymore, while the driving force acting on the pile continues to increase beyond themaximum driving force (Pdriving) max, then before stopping driving, use force maintainingvalve (Pdriving) max for 5 minutes

Where the driver does not have a holding valve, it must be driven three to five times withthe maximum driving force (Pdriving)

C Allowed tolerance :

At the bottom of the pile end, the tolerance should not be more than 75 mm compared tothe design position, tilt of the pile shall not exceed 1%

d.Time for locking the pile end:

Time for locking the pile end partially or wholly is specified by the designer

Purpose of locking the pile end is to:

Mobilize the pile to work at the appropriate time during the load increase of the work.Ensure that the work is not subject to large subsidence or uneven subsidence

- Locking the pile end must be fully implemented:

+ Fix the pile end according to the correct altitude

+ In case, the pile hole does not ensure the taper according to the regulations, need torepair the taper, sanding the sides of the pile hole

+ Fill for ompensating around the pile with medium grained sand, compact to thealtittude of lining concrete layer

+ Place steel mesh for pile end

- Concrete for locking pile end must have a grade not less than the concrete grade ofthe foundation and must have swelling, to ensure swelling 0.02

- For pile stuck to the platform 10 cm, the pile end must be at altitude - 1.55 m

e Report of pile driving history

History of pile driving shall be recorded in the process of construction including thefollowing contents:

- Date of pile casting

- Pile number, location and dimensions of the pile