Tuyên bố phương pháp này cung cấp thông tin chi tiết về quy trình, nhân lực, thiết bị, vật liệu và các tài liệu liên quan liên quan đến việc thực hiện công việc cho cống chữ U bê tông cốt thép & tấm che theo các Thông số kỹ thuật chung, đặc biệt và bổ sung. Mục đích của Tuyên bố phương pháp này là cung cấp thông tin và đóng vai trò là hướng dẫn để thực hiện công việc đúng cách tại công trường nhằm tránh sự chậm trễ và đạt được chất lượng và an toàn tối đa.
GENERAL DESCRIPTION
Project Information
The Cambodia Road Connectivity Improvement Project (CRCIP) is being implemented by the
Ministry of Rural Development (MRD) in Cambodia with funding from the World Bank (WB)
The project aims to support the improvement of climate resilient road accessibility in three (3) provinces, namely: (i) Kampong Cham, (ii) Tboung Khmum, and (iii) Kratie
The RCIP which includes a total of 27 roads with a total length of 277.3 km is located in three provinces of Cambodia, namely: (i) Kampong Cham, (ii) Tboung Khmum, and (iii) Kratie Of which, 7 roads with a total length of 75.3 km are located in Kampong Cham province, 6 roads with a total length is 67.6 km is located in Tboung Khmum province, and 14 roads with a total length of 134.4 km are situated in Kratie province
RCIP is divided into 3 civil work package by provinces and CW1 covering Kratie province subdivided into 2 lots: CW1-Lot 1 (72.9Km) and CW1-Lot 2 (61.5 Km)
In there, CW1-Lot 2 include 6 roads: KRT-1 (11.1 Km), KRT-2 (8.2 Km), KRT-3 (11.9 Km), KRT-
6 (14.2 Km), KRT-20 (8.1 Km) and KRT-29 (8.0 Km) CW1-Lot 2 location is shown as Figure
Figure 1.1-1 Location of Contract Package on CW1-Lot 2
Project Objective
The Cambodia Road Connectivity Improvement Project (RCIP) will support the improvement of climate resilient road accessibility in targeted provinces The Royal Government of Cambodia
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 4
(RGC) has requested the World Bank (WB) provide an Investment Project Financing (IPF)
Targeted provinces under the proposed investment include Kampong Cham, Kratie, and Tboung
Khmum with a total population of over 2.3 million people The design of the proposed project builds on a network connectivity approach to improve road accessibility in rural areas, between rural areas and urban centers, and to the main network The project provinces were selected considering several criteria including density of rural population, agricultural potential, vulnerability to floods, condition of roads, and connectivity of provincial road networks to cover larger geographic area
Road works will help to improve climate resilience and safety of road infrastructure The scope of works will include paving/sealing of the roads with climate adaptation and resilience measures and improving bridges and other road structure to climate-resilient standards The technical design will ensure that the identified climate-resilient measures reduce transportation costs and flooding risks and achieve the target of creating durable access to the main road network, markets, and services for the rural population.
INTRODUCTION
Reference Construction Specification
Description
The work shall include all relevant necessary works to complete a Reinforced Concrete U-drain &
Cover at the location shown on the Drawings or as per the Engineer’s General Specifications and to the layers, lines, levels, grades and dimensions shown on the Drawings
The body part of Reinforced Concrete U-drains shall be constructed by the direct casting-in-site method on site The Cover Slab shall be constructed by precast method at the contractor s’ precast yard Below is a typical of Reinforced Concrete U-drain & Cover
Minor Drainage Structure 6.4 General Specification
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 5
Figure 2.2-1 Cross Section of U-Side Drain
SCOPE OF WORK
Description
The scope of work covers the following activities such as
+ Preparation works (Manpower, Equipment, Materials etc.);
+ Setting of Traffic Safety Devices;
+ Construction of Body part of U-drain, Cover Slab…etc.;
+ Backfill material for U-drain and other related works.
Table List of RC U-Side drain & Cover under Project Scope
No From PK To PK Length (m) LHS/RHS Type Remarks
Table 3.2-1: Table list of RC U-drain & Cover under Project Scope
Work Quantities
The following tables are the estimated quantities of RC U-drain and Cover slab from the Bill
Quantities of the main Contract intended for references only and not for measurement purposes
Quantity might change in actual site condition
Description Items No Unit Quantities
Concrete U-drain & Cover Slab (Type - A) 6.4(1a) m 1228.07
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ORGANIZATION CHART
Organization Chart is as follow:
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 7
MANPOWER AND EQUIPMENT
Equipment
Table of Main Equipment serving for the construction:
No Equipment Capacity Unit Qty Remarks
2 Dump Truck 15T each 2 Hauling of Materials
3 Mobile Crane 25T each 1 Lifting Works
4 Tamping Rammer 3T each 2 Compaction Works
5 Spud Vibrator 800w each 3 Compaction of Concrete
6 Generator 25 KV each 1 Power Supply
7 Water Pump each 2 Dewatering (if any), Concrete Curing
8 Agitator Truck 10m3 each Varies Concrete Supplier
9 Survey Instruments Set 1 Serving survey works
10 Minor Tools Gloves, hammer, shovel, bucket…etc
* Note: This equipment will be increased according to the site requirements
Manpower
Manpower to be mobilized for construction work as below:
No Description Unit Qty Remark
8 Safety Worker Person 2 Depend on site condition
* Notes: This manpower will be increased according to the site requirements
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 8
MATERIALS REQUIREMENT
List Table of Materials used for construction of RCBC Works
Used for U-drain & Cover slab
6 Reinforcement Bars Steel Bars: D8 Used for RC Structural items
7 PVC Pipe Type PVC ỉ30mm Installation on Body U-drain
Concrete
Concrete type use for reinforced concrete U-drain works shall as below Table 6.2-1:
Class B1 362 0.49 50 - 100 No 67 (19.0 mm - 4.75 mm) 32Mpa
Class E 307 0.58 50 - 100 No 357 (50.0 mm - 4.75 mm) 17Mpa
Table 6.2-1: Table list of Concrete type use for RC U-drain works
The classes to be used for the various structures and structure components shall be as designated in Table 6.2-2
Class B1 Reinforced Concrete for Body Part, Cover slab
Class E Used for Blinding Concrete
Table 6.2-2: Concrete classes for U-drain components
Concrete shall consist of a mixture of Portland cement, water, and coarse and fine aggregate with or without admixture Material requirements of Concrete, Please Refer Clause 5.1 of General
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 9
The Contractor will design the concrete mixes and submit his proposals for the approval of the
Bar Reinforcement
Bars for concrete reinforcement shall conform to the material properties specified in AASHTO M
31M, Deformed and plain billet-steel bars for concrete reinforcement, Grades 300 and 400
Deformed bars shall be Grade 400 and plain round bars shall be Grade 300 Bars diameter shall be as shown on the Drawings and in accordance to the requirements as specified in Clause 5.2 of
Selected Backfill Material
Backfill shall be approved suitable material and shall be free from large lumps, wood and other deleterious materials Material for backfill shall conform to the requirements of select fill material as specified in Clause 2.6.2 of General Specifications
Where required on the Drawings, or instructed by the Engineer, selected porous material may be used in backfill to structures as specified in Section 5.8 of General Specifications
Sand used for porous backfill material shall conform to the following grading requirements
Sieve Designation Percentage by weight passing square mesh sieves (AASHTO T27)
Table 6.4-1: Percentage by weight passing square mesh sieves of Sand
Crushed rock used for porous backfill material shall conform to one of the following grading requirements
Sieve Designation Percentage by weight passing square mesh sieves (AASHTO T27)
Table 6.4-2: Percentage by weight passing square mesh sieves of Crushed rock
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 10
TESTING AND SAMPLING
Lab
The contractor will submit to the consultant a qualified testing unit The profile will be submitted separately by the contractor The experimental unit will serve the project with the approval of the consultant.
Testing Standards
Unless otherwise specified, all tests shall be performed in accordance with the methods used by
AASHTO/ASTM and shall be made by the Engineer or his designated representative.
Sampling and Testing Frequency
Table 7.3-1: Sampling and Testing Frequency for Concrete works
No Stage/ Activity Inspection required Reference Method Frequency
1.1 Approval of Mix Mix designing Standard: ACI 211.1-91
Gradation AASHTOT-27 2 per Stockpile plus 1 per 1,000 cu-m Unit Wt AASHTO T-19 1 per Source plus 1 per 1,000 cu-m Specific Gravity AASHTO T-85 2 per Source plus 1 per 500 cu-m Absorption AASHTO T-85 1 per Source plus 1 per 500 cu-m Abrasion AASHTO T-96 1 per Source plus 1 per 500 cu-m Soundness AASHTO-104 1 per Source plus 1 per 500 cu-m Deleterious Substance AASHTOM-80 1 per Source plus 1 per 500 cu-m
Gradation AASHTO M-6 2 per Stockpile plus 1 per 800 cu-m Unit Wt AASHTO T-19 1 per Source plus 1 per 800 cu-m Specific Gravity AASHTO T-84 2 per Source plus 1 per 800 cu-m Absorption AASHTO T-84 1 per Source plus 1 per 800 cu-m Organic Impurities AASHTO T-21 1 per Source plus 1 per 800 cu-m Soundness AASHTO-104 1 per Source plus 1 per 800 cu-m
Deleterious Substance AASHTO M-6 1 per Source plus 1 per 800 cu-m
Petrographic - 1 per Source plus 1 per 800 cu-m
Setting Time AASHTOT131 1 per Lot or 1000 bags
Mortar Strength AASHTOT132 1 per Lot or 1000 bags
Yield Test for Cement Content AASHTOT121 1 per Lot or 1000 bags
Water Chemical Test AASHTO T-26 1 per source
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 11
Production Properties of mix Every Batch
2.1 Length, width & height of work Line & level As per the drawings Per item 2.2 Formation level Bottom & Finish level As per the drawings Per item
3.1 Fabrication Sizes, spaces as per the Drawing Visual inspection Per item 3.2 Installation Location, Space etc Visual inspection Per item
4.1 Workability Slump & temperature Visual inspection Per quantity
4.2 Placing Evenness, within 1.5hrs of production Visual inspection Per quantity
4.4 Curing Proper watering (Minim um 7 days) Visual inspection Per item
Table 7.3-2: Sampling and Testing Frequency for Steel bars
No Stage/ Activity Inspection required Reference Method Frequency
1.1 Reinforcing Bar Tensile Strength AASHTO M 31M 1 Sample per 10 tones
2.1 Fabrication Sizes, spaces as per the Drawing Visual inspection Per item 2.2 Installation Location, Space etc Visual inspection Per item
Experimental Work
- Contractor will provide full test certificates, origin of all supplier's materials
- The material criteria shall conform to the requirements in Sub-Clause 6 “Materials
Requirement” of this Method Statement and the requirements of Project General Specification
- All tests shall be conducted in a manner approved by the engineer and shall be conducted in the contractor's laboratory
All concrete used in the Works shall be subject to sampling and testing strictly in the manner prescribed in AASHTO Testing Specifications T-22, T-23, T-97, T-126, T-119 and T-141 and in accordance with the requirements as detailed in technical Specifications
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 12
Samples shall be taken from separate batches of concrete selected at random during the placing operation Two cylinders (minimum) shall be cast from each sample in purpose-made steel moulds conforming to AASHTO T-23 and identified as a matched set Each cylinder shall be identified with the batch and/or lot as directed by the Engineer and a written record made of the location of each batch within the structure In addition, for precast concrete, the cylinders shall be so marked that they can be readily identified with the corresponding structural unit at all times
Samples of the steel lot delivered to the site will be taken for testing at the request of the engineer
The frequency of testing for reinforcement shall not be less than the following frequency: 1 time/ each type of diameter/ each batch of steel delivered to the site Additional tests may be required by the engineer
All rebar tests shall conform to the requirements and specifications of the AASHTO standards
Backfill material will be applied on both sides of U-drain at the foundation pit location with the thickness and density of each layer in accordance with the requirements of the technical instructions After completing each layer, FDT test will be carried out according to current standards and under the direction of the engineer
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 13
CONSTRUCTION PROCEDURE
Work Flow Chart
The Work Flow Chart is shown in Figure 8.1-1 below
Figure 8.1-1: Work Flow Chart of Reinforced Concrete U-Drain
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Preparation Works
- Submitting construction method documents to consultants, Approved Construction Drawing
- Testing and Inspection of materials supplied for works
- Arrange traffic safety control devices at the working area (See Figure 8.2-1)
- Site preparatory works also includes mobilization of manpower and equipment, clearing and grubbing, construction area for fabrication and storage area and fabrication of rebar and formworks
- In case of water presence on the area, dewatering system will be provided to eliminate the presence of water and to enable a dry working area
Figure 8.2-1: Traffic Control for Construction Stages
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 15
Survey Works
- Prior to start the excavation works, setting-out points will be established at site by Surveyor
- Lay out and elevation points will be indicated on the line and grade stakes installed at site for construction references
- Any deviation found between actual site condition and approved shop drawing shall be informed to the Engineer
- Temporary control points should be checked daily before the commencement of the work
Road BM/ TBM Sta N (m) E (m) Elevation (m)
Excavation and Demolition Works
- Excavation works shall be undertaken using conventional Excavator combined with manual digging
- Bottom of excavation shall be up to 20cm average above the designed bottom of U-Drain Depths shall be checked and monitored carefully to prevent damage and disturb the subsoil of foundation
- Excavated materials found to be suitable for backfill and embankment shall be hauled to a designated area and shall be protected to keep dry Unsuitable materials as Concrete debris and unused excavated soil will be removed from site and transported to designated disposal area by dump trucks
- Manual trimming, leveling and excavation shall be done on the remaining 20cm average from the first step of excavation up to the designed bottom elevation of excavation pit After removal of excavation material is completed, formation level surface will be compacted using tamping rammer or plate compactor to present a uniform surface true to line and grade conforming to the cross section shown in the approved drawing
- If existing ground condition is unsuitable materials, it will be removed and replaced with approved selected materials as directed by the Engineer and compacted layer by layer to a density of not less than 90% of MDD
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 16
Figure 8.4-1: Excavation Works by Excavator machine
Figure 8.4-2: Manual digging to treating bottom foundation pit
Figure 8.4-3: Compaction and Leveling Works of Ground Surface
Construction of Leveling Concrete
- After the compaction and leveling of ground surface, Surveyor will establish the setting out points for formworks alignment reference in accordance with approved shop drawing
- Concrete pouring will proceed after formworks is installed Ready mix concrete will be class E with 17Mpa designed compressive strength Concrete to be compacted by vibrators
- Ensure that concrete shall not be dropped freely more than a vertical distance of 1.5 meters during casting
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 17
Figure 8.5-1: Concrete pouring of lean concrete
Construction of Bottom Slab
- Diameter of re-bars should be checked thoroughly with the shop drawing prior to start the rebar installation
- Ensure that fabricated rebar shall conform with the approved bar bending schedule
- Surveyor will establish the setting out points and marked on the surface of lean concrete prior to installation of re-bars and formworks in accordance with approved shop drawing
- After setting out points are established, installation of top and bottom re-bars including wall starter bars will proceed in accordance with the arrangement shown in the approved drawing
- Concrete covering, spacing and splicing of Re-bars will be thoroughly checked during and after the installation
- Adequate chair bars and concrete spacers will be provided to maintain the required concrete covering
- All reinforcement to be hot rolled grade 400 deformed bars to AASHTO M-31M-86
Figure 8.6-1: Bottom Slab Re-Bars and Vertical Starter Bars
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 18 b Formworks Installation
- Formworks will proceed after the rebar installation is completed
- Formworks are consisted of plywood panel adequately supported with timber at all sides to withstand the upward and lateral pressure produced by concrete during concreting c Concrete Pouring and Curing
- Prior to concrete pouring ensure to remove deleterious materials by air compressor and surfaces on which concrete is to be placed will be thoroughly moistened with water
- Concrete class B1 with 32Mpa designed compressive strength will be delivered at site by concrete mixer truck and poured to the casting area by either excavator and bucket or concrete trough or other devices depend on the availability and actual site condition
- Ensure that concrete shall not be dropped freely more than a vertical distance of 1.5 meters
- Temperature and slump, air content of fresh concrete will be checked prior to concrete pouring
- Fresh concrete will be spread and compacted by concrete vibrator and finished manually by using trowel
- The concrete surface will be covered with wet burlaps after finishing with trowel Wet burlaps assuring material will be spread with water every day and kept wet for at least 7 days after placing the concrete
Figure 8.6-2: Concrete Pouring Bottom Slab
Construction of U-Drain Body Wall
a Rebar Installation for Body Wall
- Diameter of re-bars should be checked thoroughly with the shop drawing prior to start the rebar installation
- Ensure that fabricated reinforcement bar will be in accordance with the approved bar bending schedule
- Install the vertical and horizontal bar in accordance with the spacing and arrangement shown in the approved drawing
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 19
- Vertical and horizontal rebar spacing, concrete covering and splicing will be thoroughly check during and after the installation
- Adequate concrete spacers shall be provided to maintain the concrete covering
- To tie P.V.C pipe ỉ30 @2000 into concrete U-Drain as shown on the Drawings
- All reinforcement to be hot rolled grade 400 deformed bars to AASHTO M-31M-86
Figure 8.7-1: Wall Re-Bars b Formworks Installation for Body Wall
- After wall rebar installation are completed, formworks for wall will commence
- Surveyor will establish the setting out points for the alignment of formworks in accordance with approved drawing
- Formworks are consisted of plywood panel and supported with timber as frame Forms will be fixed with steel pipes as horizontal supports, tie rods and shoring to maintain stability and to withstand the upward and lateral pressure produced by concrete during concreting
- After installation of formworks, alignment and verticality will be double checked to ensure no deviation of forms occurred
Figure 8.7-2: Formwork for Body Wall
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 20 c Concrete Pouring and Curing for Body Wall
- Prior to concrete pouring, ensure to remove the deleterious materials by air compressor and surfaces on which concrete is to be placed will be thoroughly moistened with water
- Concrete class B1 with 32Mpa designed compressive strength will be delivered at site by concrete mixer truck and poured to the casting area by either crane and bucket or concrete pump truck depend on the availability and actual site condition
- Ensure that concrete shall not be dropped freely more than a vertical distance of 1.5 meters
- Fresh concrete will be spread by shovels, compacted by concrete vibrator and finished using trowel
- Adequate slope should be provided on top slab to avoid water accumulation and to have a positive water runoff
- After finishing with trowel and when concrete started to set, surface will be cover with wet burlap
Wet burlap as curing material shall be spread with water every day and kept wet for at least 7 days after placing the concrete
Figure 8.7-3: Concrete Pouring for Body Wall
Prefabricate the Reinforced Concrete Cover Slab
- Installation of re-bar, shaped formwork and pouring concrete of cover slab
- Pour concrete in a direct method combining with manual pouring
- Concrete of cover slab shall be class B1 with 32Mpa designed compressive strength
- Compact with a table rammer, and use a wooden trowel to smooth the surface
- Take sample for test of concrete as Project requirement
- Remove formwork and curing concrete as per Specifications
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 21
Figure 8.8-1: Prefabricate the Reinforced Concrete Cover Slab
Installation of Reinforced Concrete Cover Slab
- Transfer the cover slab from stockpile yard to site (after concrete reached designed strength)
- Remove excess materials and soil in the trench before installing the cover slab
- Workers will install the cover slabs at location as per drawing
Figure 8.9-1: Installation of Cover Slab
Backfilling Works
- When permission is granted by the Engineer, backfilling works will commence
- Remove all obstructions and thorough housekeeping will be carried out
- Selected backfill materials approved by the Engineer will be delivered at site by dump trucks and stored near the area to be backfill
- Stock pile will be properly cover with plastic or blue sheet to protect from rain and other extraneous materials
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 22
- Approved backfill materials will be distributed to both sides of U-Drain by excavator and spread manually by manpower with the use of shovel
- Selected backfill materials (Suitable material as Sand, crushed rock or as directed by the engineer base on General Specification) will be compacted layer by layer using tamping rammer or plate compactor to a thickness of 150mm and field density of not less than 90% of MDD
Site Restoration
As soon as the construction of U-Drain is completed, Contractor will restore the site as closely as the original condition as possible and to the satisfaction of the Engineer.
QUALITY CONTROL
- QC Engineer shall inspect all work to ensure compliance to the requirement of Specification and
- Strictly control of materials according to specifications and construction equipment All materials to be used for this work shall be subject to Engineer’s approval
- Method statement: “Quality Assurance Plan” shall be submitted separately and shall be a part of this Method Statement
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 23
Description: The completed construction items will be inspected by the contractor's field engineer The qualified items will be reported to the contractor's office by the field engineer The contractor's quality control department will plan to inspect the construction quality After the item meets the quality requirements and is approved by the contractor's quality director, the contractor will plan and notify the consultant about the joint site inspection between the contractor and the consultant After the consultant inspects and approves the work, the contractor will carry out the construction of the next work items in accordance with the construction phase All unapproved work items will be resolved and handled by the contractor so that the work items meet the project requirements The next work will not be constructed without the consent of the consultant a Testing
Air Content (refer AASHTO T-152/ C231) A1, B1, B2, B3 shall not be more than 4%, +/-1 b Construction Tolerances
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 24
Spacing of Re-Bars ± 20mm
TRAFFIC SAFETY CONTROL
Maintenance of Existing Road and Bridges
When public traffic is to be passed though the Works in an incomplete state the Contractor shall take all steps necessary to provide a smooth free-draining running surface and to maintain it in that condition
The contractor shall ensure that the surface is neither excessively dusty nor dangerously slippery and shall, if directed by the Engineer, water the surface to lay dust or provide a thin gravel topping to the trafficked surface
The Contractor shall ensure that safe access is maintained at all times across bridges and culverts within the limits of the site This may include the repair or replacement of bridge deck materials or the construction of a by-pass where more appropriate, but at all times the Contractor should not delay the passage of vehicles for excessive periods
The Contractor shall render such assistance to the public as shall be necessary to allow safe and convenient passage of traffic at all times
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 25
Traffic Closing Basis
- Part of lanes shall be closed to execute without changing the directions of the traffic flow in the existing road A section shall be rationally divided based on the principles of facilitating the construction vehicles to enter or leave the site and the passing vehicles to pass smoothly
- All traffic control measures shall be in operation 24 hours per day and shall be supplemented by lights at night when the Engineer considers this necessary
- At least two weeks before he intends to alter trafficking patterns in any way the Contractor shall present plans to the Engineer for traffic signing and control If the Engineer does not approve these plans the Contractor shall make such amendments to them as are necessary in order to make them, in the Engineer’s opinion, satisfactory Prior to implementation of the new trafficking arrangements, the Engineer shall inspect the Contractor’s signs, barriers and signals and only when the Engineer agrees shall they be put into operation
- Some typical arrangements for traffic safety control:
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Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 27
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 28
Site Layout
Part of lanes shall be closed to execute without changing the directions of the traffic flow, which is to say one or two lanes be closed, the rest is used to pass through
The control area is divided into the parts: warning zone, buffer zone, operation zone and termination zone
Warning zone: 200m-long warning zone shall be set, in which the signs of "Speed Limit",
"Operation Ahead", "No Overtaking", "Narrow Lane Ahead", "No Passing" shall be marked The space between adjacent signs shall be less than 30m, usually 10m to 30m The last sign is at a distance of not less than 15m from the first device (tapered sign) of the upper transition zone
Buffer zone: The length of buffer zone is 8m The reflective cone is transited gradually to the traffic lane
Operation zone: 0.l-0.5km-long operation zone shall be set as a construction unit, one half widths of which is closed for construction The tapered signs with interval of 2- 4m are placed on the sides of construction area
Termination zone: The length of the termination zone shall not be less than10m The sign of
"Restored Traffic" shall be placed at the end of the termination zone
The special person shall be appointed at the beginning and finishing end of the closed sections to direct traffic with a red flag
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 29
Traffic Control of Blocked Sections
The construction of bridges or culvert or road section will affect the circulation of the vehicles on the Road, the contractor tends to occupy the entire road or a part of road Therefore, at each construction site and based on the actual conditions on the construction site, the contractor will propose a solution to block the entire road or a part of the road to serve the construction process of the items In case of blocking the entire road section, we will construct a detour or a plan to direct traffic on another suitable route to ensure two-way traffic according to technical requirements and limit congestion
At locations where traffic needs to be blocked, the contractor will have a specific plan and discuss with the consultant before implementing the work b) Some regulations of safety
- For construction personnel in accordance with the safety regulations for construction The
Personal Protective Equipment shall be worn
- No drinking, slippers, and sandals are allowed on site
- The insurance fee shall be paid on time and warning flashlights be installed for the construction vehicles
- The traffic rules shall be com plied with and no parking on the lane or turning around randomly be permitted for construction vehicles
- A full-time safetyman shall be arrangement to supervise the execution of the project
- The finished sections shall be protected carefully, and roadblocks or warning signs shall be placed if necessary
- The damaged safety signs which affect the expression of the safety information shall be replaced in time
- Safety signs shall be placed in bright environment and at a proper distance from the danger location so that the relevant people have enough time to note the information that it represents
- The safety signs with dirt, grease shall be cleaned timely to ensure the safety information without the mistakable messages
- The safety signs with displacement shall be adjusted in place to avoid accidents, which result from the relevant people's not quickly noticing and understanding the safety information.
ENVIROMENT AND SAFETY CONTROL
Safety Control
Prior to starting of construction works, warning signs and instruction boards shall be fully installed either inside or surrounding the construction site and the following particular matters are to be through to all members working in the construction site in order to complete the work efficiently without any accident or casualty
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 30 a) Joint Meeting
- Prior to start any activity, a joint meeting with relevant staffs shall be held for the purpose of general explanation on the whole contents of works as well as the method for the implementation of efficient work b) Basic Instruction
- All workers shall always wear Personal Protective Equipment (PPE), such as hardhat (helmet), safety shoes, hand gloves and working uniform c) Prevention of Accident by Heavy Machine
- Only skilled operator shall be allowed to operate equipment on site In case of new operators, a test of skill shall be conducted first prior to his acceptance to the job Preventive maintenance check shall be done regularly at equipment working at site prior to full operation Stability of working area and foundation of equipment shall be checked particularly at locations of outrigger and track pad of cranes
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 31 d) Prevention of Accident of Electrocution
- Electric generating equipment shall be properly protected and properly installed with earth connection Electric wires shall relate to electrical tapes to prevent electric leakage Only skilled operator shall be allowed to operate equipment on site e) Prevention of Accident in Night Shift Works
- Enough lighting system shall be provided for night shift works especially installed at working platforms If necessary, all the surrounding working area shall be lighted up The people who work on the site must wear reflective jacket, if worked at night f) Existing Facilities
- Existing facilities especially existing overhead electric line, water line, telecommunication line and other important facilities at surrounding area shall be taken with care not to damage.
Environmental Control
Responsibility for surrounding environment during construction and shall comply with the
Condition of Contract on Protection of Environment
If any other problems occurred in the site, applicable counter measures or prevention action shall be considered immediately and executed as soon as possible
The Contractor shall be responsible for implementing and managing mitigation measures during the construction of the Works The recommended mitigation measures are presented below a) Ambient air quality
- Exhaust emissions from construction equipment shall be strictly controlled in accordance The
Contractors are requested to use standard equipment
- Where possible the Contractor ’s chosen access routes to and from the site should avoid residential areas Vehicles carrying sand, aggregates or other loose materials shall be fully covered Brushing and watering shall be used where required to control dust and the spraying of mud
- Stockpiles should be covered or kept damp to avoid windblown dust
Method Statement for Construction of Reinforced Concrete U-Drain & Cover Slab Page 32
- The Contractor shall be co-ordinate his activities with local environmental management authorities to control and supervise the ambient air quality within the program of regional pollution control
- Spraying Water for Dust Control: To protect the passenger and the residents from dust during construction period, the Contractor shall spray water along the road at least two times per day except rainy season or directed by the Engineer b) Noise and vibration level
- The Contractor shall use equipment and facilities conforming to Standards for traffic noise level
- In order to protect residents’ houses, public buildings and other structures, the maximum vibration at these locations should ensure the allowable range c) Water environment
- To ensure the water quality of local watercourses, ponds, and lakes the Contractors shall comply with the following environmental protection measures Care shall be taken with fuels and oils
- No waste material of any kind shall be disposed of into local watercourses, ponds, or lakes
- Stationary construction equipment, offices and accommodation, workshops and storage areas and other temporary facilities shall not be located near to local watercourses, ponds, and lakes
- Oil waste shall be collected, treated, and disposed of in approved disposal areas
- Fuels and oils shall not be stored nearly local watercourses, ponds or lakes and shall be stored in areas located at least 200m away from such water features
- Oil and fuel storage tanks shall be at an elevation higher than the flood level Warning signs shall be installed at all fuel storage areas to avoid collision with construction equipment
- Suitable temporary drainage should be provided to prevent localized flooding or contaminated run-off from the site and to ensure construction work is not damaged or delayed by standing water.
APPENDIX
Some Photo of Main Equipment/ Tools used in Construction