Biện pháp mô tả chi tiết quy trình thi công đường tránh phục vụ trong thi công ( Cầu, Cống ). Biện pháp được biên soạn dựa trên chỉ dẫn kỹ thuật dự án, tiêu chuẩn AASHTO, TCVN
GENERAL DESCRIPTION
Introduction
This method statement provides the details of the procedure, the manpower, the equipment, the materials and relevant documents related to construction Detour road including the quality control verifications, the measurement verifications, and also the safety precautions and environment protection to be implemented for this work.
Project Information
The project road connects Tbong Khmum district to Kratie province of the Cambodia, stretching along the northern, to Kratie province The road passes on a comfortable alignment through flat/wavy terrain along the toe of hilly land Four (4) rather sharp curves along the road are considered non-critical due to adequate super-elevation of the road way and appropriate signage.
The traffic on the road is a medium mix of private cars and quite heavy trucks that contribute mainly to the road wear The PR.377 and PR377A of RCIP are located in Kratie province The length of the PR377 is 35.00 km and the PR377A is 13.593km The location of the packages is shown in Figure-1
Figure 1.2 Location of Contract Package on CW-3(PR377 & PR377A)
Project Objective
The objective of the project is to ensure continued effective use of the rehabilitated national and provincial road network in support of the economic development in Cambodia It will do so by improving the institutional and technical capacity of the Ministry of Public Works and Transport for road maintenance planning, budgeting and operations as well as by expanding of strengthening maintenance activities.
The project seeks to contribute to cultivating a road asset management culture within the sector by: (i) expanding maintenance of the national road infrastructure nationwide and facilitating interventions in priority areas, (ii) allocating adequate maintenance funding during the budgeting process; (iii) knowledge building in MPWT on road network management, maintenance technology and contract management; and (iv) private sector involvement in competitive bidding and performance quality.
Project is expected to bring significant benefits to local residents in six Cambodian provinces,Kampong Chham, Tbong Phmum, Kratie, Mondulkiri, Ratanakiri and Stung Treng province; by reduced travel times and cost, less arduous journeys and better connectivity along the national road network It is intended that the benefits to local populations are maximized, and to ensure that the benefits are shared by local communities.
Topography and Climate
The topography in the project area is mainly flat with some hilly sections and the road elevation varies from minimum 23.52m to maximum 50.95meter The maximum temperature is around40°C, the annual temperature fluctuates more than 10°C and from 6 – 7°C in a day In hot weather the absolute high temperature may be up to 39°C (in April) By contrast, in January the absolute low temperature may descend to 16°C.
Rainfall Records
The available hydrometeorological data such as rainfall are obtained from the Kratie Provincial Department of Water Resources and Meteorology (PDoWRAM) The rainfall station is located at (Xa0976, Y79728) The data ranged from 1980 to 2019 is considered to conduct frequency analysis for hydrologic modeling The 24hr maximum annual rainfall over 3 decades were extracted for the analysis as shown in Figure 4.1 and 4.2 below From the figure below, it’s clearly observed that the highest rainfall over the period was in the year of 1988 with a value above 250mm, followed by the year of 1982 as the second highest with the precipitation of above 270mm The year 2009 is observed to have above 150mm which was the highest rate over the 10 year after 1992 and it was revealed during the Ketsana storm In 2001 was noted as lowest rainfall, it’s reflected to the Drought period.
Figure 1.5.1 Daily Rainfall Ditribution in Kratie 1980-2019
DESCRIPTION OF WORKS
Scope of Works
This is method statement for constructing Detour road, serving traffic flow as well as supporting during the construction of the bridge or Box Culvert
Summary table of Detour Road :
Standards and Technical specification related
CAM PW 04-102-99 Bridge Design Standard (Cambodia, 2003)AASHTO, 2002 Standard Specifications for Highway BridgesOther Standards related b) Technical specification
+ Section 2.1: Clearing and Grubbing/ Section 2.6: Embankment/ Section 3.1: Sub-Base + Section 5.1: Concrete of Specifications
+ Section 5.2: Reinforcement of Specifications + Section 5.5: Steel Structures
Construction Schedule
Construction Schedule shall be referred to latest approved Schedule.
ORGANIZATION CHART
Organization Chart is as follow:
POLY CHANDA ENGINEERING CO., LTD
MANPOWER AND EQUIPMENT, SITE ARRANGEMENT
Equipment
Equipments proposed as in Table below:
Item Name Unit Quantity Remarks
* This equipment will be increased according to the site requirements.
Manpower
Manpower to be mobilized for construction work as below:
1 Site Manager 1 On-site organization arrangement
2 Site Engineer 1 On-site management
3 Quality inspector 1 Construction quality management
* This manpower will be increased according to the site requirements.
Site Arrangement
During the construction of Detour Road, traffic will be maintained on the main bridge The contractor will install protective fences, sign systems, night lights and workers to guide traffic on both sides of the bridge b) Temporary Facility layout
No Descriptions Area Unit Quantity Note
10 Material storage yards 50 x 10 m2 500 c) Plan for supply of power, Water, And Ful, Etc.
The contractor will register to use the local water source for production.
Where it is not available, using water shall be transported to the site.
Local electric network will be connected in the power-available place and considering the sustainability of construction, the generating set shall be prepared as a standby source of power in case of power failure Where it fails to connect with local electric network, the generating set shall be used.
The fixed telephones and Internet shall be installed in Project Management Office; Key personnel shall be supplied with cell phones to facilitate the internal and external communication.
Supply Sources of Major Materials
Given the quality of material is ensured and adhere to the principle of best use of local materials, to make an extensive investigation on material sources, prices, traffic conditions, means and costs for a good economic and technical comparison Choose the best material and deliver them according to plans In addition to the materials which are supplied by the Employer, asphalt, high strength steel bars, pre-stress wire, bridge bearings will be met by purchasing them in China Most of fuel and oil will be purchased locally, the rest will be purchased from China.
We have rich labor and technician reserves which can be delivered to the site as plan,and we can also recruit some labors locally.
CONSTRUCTION OF DETOUR ROAD
Materials Requirements
Material for foundation fill shall consist of suitably graded sand, gravel, or stone as shown on the Drawings or required by the Engineer. b) Concrete
Concrete shall conform to the general requirements of Section 5.1 “Concrete” of Technical Specification. c) Backfill Material
Backfill shall be approved compac table granular material and shall be free from large lumps, wood and other deleterious materials It shall be obtained from the structural excavation if such material is approved by the Engineer as suitable Any additional material needed shall be obtained from roadway or borrow excavation unless otherwise directed by the Engineer.
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 Specifications.
Sand used for porous backfill material shall conform to the following grading requirements:
Percentage by weight passing square mesh sieves (AASHTO T 27)
Gravel and crushed rock shall conform to one of the following grading requirements:
Percentage by weight passing square mesh sieves (AASHTO T27)
Reinforced concrete culvert pipes shall be preferably of the tongue and groove type rather than of the bell and spigot type They shall be constructed in accordance with the details shown on the Drawings Butt jointed pipes will not be permitted.
Concrete used in the construction of reinforced concrete culvert pipes shall be in accordance with Section 5.1 of Specifications, except where modified by the Drawings.
Steel Reinforcement used in the construction of reinforced concrete culvert pipe shall be in accordance with Section 5.2 of Specifications, except where modified by the Drawings.
Mortar for joints shall contain one part Portland cement and two parts sand by dry volume unless otherwise required by the Drawings or these Specifications The sand shall conform to the requirements of AASHTO Standard Specification M 45.
The amount of water in the mix shall be such that the consistency of the mortar is suitable for the purpose intended and to the satisfaction of the Engineer All mortar shall be used within 30 minutes of adding the water.
Reinforced concrete pipes may be tested, at the discretion of the Engineer, in accordance with the requirements of AASHTO T 280.
Permissible variations in dimensions - The internal diameter of 300-600 mm pipe shall not vary more than + 1.5% from the design diameter The internal diameter of 700 mm - 2.7 m pipe shall not vary more than + 1.0% or 10 mm, whichever is greater, from the design diameter The wall thickness shall not be less than that shown in the design by more than 5% or 5 mm, whichever is the greater.
A wall thickness more than that required in the design shall not be a cause for rejection.
Pipes having localised variations in wall thickness exceeding those specified above shall be accepted if three edge bearing strength and minimum steel cover requirements are met.
The permissible variation in reinforcement positioning must not exceed 10% of the wall thickness or 10mm, whichever is greater However, variations exceeding this limit may be acceptable if the representative specimen meets the bearing strength requirements Regardless, the minimum cover over the reinforcement must still be 10mm.
Variations in laying lengths - Variations in laying lengths of two opposite sides of pipe shall not be more than 1% of the diameter with a maximum of 15 mm in any length of pipe except where beveled end pipe for laying on curves is specified by the Engineer The underrun in length of a section of pipe shall not be more than 1% of the diameter with a maximum of 15 mm in any length of pipe.
Pipes shall be substantially free of fractures, large or deep cracks, and surface roughness The ends of the pipe shall be normal to the walls and center line of the pipe.
The following information shall be clearly marked on each section of the pipe.
+ The name or trade mark of the manufacturer.
The quality of materials, the process of manufacture and the finished pipe shall be subject to inspection and approval by an inspector employed by the Engineer.
Pipes shall be subject to rejection on account of failure to conform to any of the specification requirements Individual sections of pipe may be rejected because of any of the following.
+ Fractures or cracks passing through the wall, except for a single end crack that does not exceed the depth of the joint.
+ Defects that indicate imperfect proportioning mixing and moulding.
+ Surface defects indicating honeycombed or open texture + Damaged ends where such damage would prevent making a satisfactory joint.
Pipes may be repaired, if necessary, because of occasional imperfections in manufacture or accidental injury during handling and will be acceptable if, in the opinion of the Engineer, the repairs are sound and properly finished and cured and the repaired pipe conforms to the requirements of Specifications.
Construction Procedures
The construction procedures are as below.
Construction Praparation
+ Installing a system of signs, stakes, and warning ropes to ensure safety during construction.
+ Gathering machinery, equipment and construction tools to the construction site.
+ Check the construction landmarks by electronic total station.
+ The contractor needs to build a system of landmarks to control straight lines, slopes, elevations and job positions.
+ Determine the boundary and put piles to locate the construction area.
Earthworks and Allied Activities
- This work shall consist of all clearing and grubbing necessary for the performance of the work covered by the Contract in accordance with these Specifications.
- The clearing and grubbing shall consist of clearing the designated areas of all trees, down timber, snags, vegetation, rubbish and objectionable material and shall include grubbing stumps and roots and reusing or disposing of all material resulting from the clearing or grubbing It shall also include the demolition removal and disposal of structures that obtrude into or encroach upon or obstruct the work, except where provided for otherwise.
- Disposal of debris and foundations remaining after removal of houses or other structures is also considered to be included in the unit rates for clearing and grubbing and no further payment will be made under this section.
- Also included in this work shall be the removal of loose pavement material, road signs, right of- way markers, kilometer stones, guide posts and all other incidentals within the limits of construction These items shall be removed, if so instructed by the Engineer, outside of the construction limits but within the proposed right-of-way The Contractor shall exercise care so as not to damage these incidental items during the removal operation All signs, markers and incidentals removed from the project shall be stacked in neat piles so they may be collected by the Employer and will become the property of the Employer.
- Attention is directed to the Contractor’s obligations under law and under this Contract withregard to damage, particularly with regard to protection of property, forest, and landscape and to responsibility for damage claims.
- Existing highways, improvements, facilities, adjacent property, utilities, services, and trees and plants designated for preservation shall be protected from injury or damage which could result from the Contractor’s operations.
- In order to reduce the risk of erosion no topsoil shall be removed from the areas outside the limits of earthworks Any topsoil outside these limits, which is inadvertently removed during clearing and grubbing operations or otherwise, shall immediately be replaced by the Contractor at his own expense.
- Trees outside the construction width but within the proposed right-of-way having a trunk girth of more than 450 mm at a point 600 mm above the ground shall not be cut down without the prior approval of the Engineer Those trees that are not to be removed shall be protected from injury or damage resulting from Contractor’s operations.
- Clearing and grubbing shall be performed on the areas designated by staking or on the Drawings or in the Special Provisions If no areas are designated on the Drawings or in the Special Provisions, the areas to be cleared and grubbed will be as directed by the Engineer.
- Areas to be cleared and grubbed shall not normally include areas occupied by existing road works, but may, at the specific instruction of the Engineer, include areas occupied by cut slopes, embankment slopes and existing drainage features.
- Clearing shall consist of the removal and disposal of everything above ground level including overhanging branches except those things the Engineer directs are to be left undisturbed The material to be cleared shall include but not necessarily be limited to trees, stumps, logs, brush, undergrowth, grass, crops, loose vegetable matter, structures (other than those structures where removal or clearance is separately specified and measured).
- Outside the limits of the earthworks, and under embankments trees and stumps more than 1.5 meters in height shall be cut to a level not more than 300 mm above ground level and not less than 450 mm below the embankment slopes and everything else to ground level In cut areas clearing shall include the removal of stumps and roots exceeding 80 mm in diameter, to a depth of 450 mm below the finished surface except that in rounding areas at the tops of cut slopes they may be cut flush.
- Grubbing shall be carried out on the area of embankment foundations where the embankment height is less than 1.5 meters Grubbing shall consist of the removal and disposal of topsoil, stumps, roots, etc., to a depth of at least 150 mm below ground level and at least 450 mm below the bottom of the lowest sub base or base course of the road pavement Materials thus removed may be used as topsoil for slope protection if they, in the opinion of the Engineer, are suitable for this.
Materials not used as topsoil shall be disposed of at locations as directed by the Engineer.
- Materials under original ground level within embankment areas which are removed during the operation of the clearing and grubbing shall be replaced by acceptable fill materials which shall be compacted to the density prescribed for layers at the depths concerned below subgrade All unsuitable materials shall be wasted and re-spread at locations specified and in a neat and orderly way as agreed by the Engineer.
- Saleable timber shall be neatly stored in an approved accessible place within or near the right of way as directed and shall be trimmed and stacked in accordance with the requirements of the appropriate Government agency.
- All other timber except timber to be used and all brush, stumps, roots, logs, and other vegetation from the clearing and from the grubbing operations shall be granulated and composted for reuse on the embankment slopes, provided that, when permitted in writing by the authority having jurisdiction over the area through which the highway is being constructed, large stumps may be disposed of without granulating or composting at locations out of sight of the roadway.
- Likewise, large stumps may, with the Engineer’s approval, be disposed of without granulating and composting out of sight of the roadway on private land In such cases the Contractor will be solely responsible for making the necessary agreements and paying expenses and claims arising from the use of private land.
Construction Of Road Structure
The sub-base material is to be furnished, placed, and compacted according to the specified lines, levels, grades, dimensions, and cross sections indicated in the Drawings This material will be placed on a previously prepared and accepted sub-grade, ensuring compliance with the designated specifications and the requirements outlined by the Engineer.
Construction Requirements Preparation of Sub-grade
Prior to sub-base placement, the sub-grade must be properly prepared and compacted as per Sections 2.2 and 2.6, with a completion distance of at least 150 meters in advance Despite any prior approval, any subsequent sub-grade damage or deterioration must be promptly repaired before sub-base installation can proceed.
+ Sub-base shall be spread in even layers not exceeding 150 mm after compaction Care shall be taken to prevent segregation, and oversized particles shall be handpicked from the deposited layer prior to compaction Patches or pockets of segregated fine material shall be removed and the layer made good at the Contractor’s own expense.
+ Immediately after each layer has been spread and shaped satisfactorily, each layer shall be thoroughly compacted with suitable and adequate compaction equipment Rolling operations shall begin from the outer edge of the roadbed and progress towards the centre, gradually in a longitudinal direction, except on super-elevated curves where rolling shall begin at the low side and progress toward the high side Sub-base composed of sandy material shall be compacted by use of vibrating equipment Each layer shall be compacted to at least 95 percent of the maximum dry density, as determined by AASHTO T 180 During compaction, the moisture content shall be so controlled that the moisture content uniformly throughout the finished layer shall be within the limits of +2 percent of the optimum moisture content as determined in AASHTO T 180 or such other moisture content as shall be agreed with the Engineer as a result of compaction trials.
Materials which do not contain sufficient moisture shall be watered prior to and during compaction to the satisfaction of the Engineer Materials containing excess moisture shall be allowed to dry to the required moisture content prior to compaction All costs involved in regulating the moisture content, both wetting and drying, shall be deemed to be covered by the unit price for sub-base Density determinations shall be carried out for each layer of sub-base constructed, in accordance with the requirements of AASHTO test T191, at a rate of 5 tests for every 2000 square meters of completed sub-base layer or part thereof For density results to be acceptable, four of the five densities measured shall be equal to or greater than the required level of compaction, and all five shall be greater than the required relative density minus 3%, and the average of all five shall be not less than the required value The construction tolerances for Sub- base shall be as defined in Clause 1.11.8 of Specifications Rectification of work outside the permitted tolerances shall be carried out in accordance with Clause 1.11.9 of Specifications.
Maintenance Process Of Steel Temporary Bridges
+ After construction is completed the sub-base shall be maintained during construction new bridge Maintenance shall include drainage, rolling, shaping, and watering as necessary to maintain the finished subbase layer in proper condition Deficiencies in thickness, composition, construction, smoothness or density which develop during the maintenance shall be corrected to conform to the requirements specified above Sufficient moisture shall be maintained at the surface of the sub-base layer to prevent the development of a dusty condition This moisture level shall be achieved by a light spraying of water at appropriate time intervals.
+ Regular inspection to detect breakdowns of road traffic works that may cause traffic insecurity or traffic jams.
+ Check the road surface, bridges, drainage system, road signal system and other ancillary works to detect damage that may cause traffic accidents.
+ If there are traffic jams such as: landslides, road landslides, flooding, broken bridges, etc., first of all, measures must be taken to ensure traffic safety (barricades, roadblock signs, etc.), and at the same time find a plan threading and fixing as soon as possible.
+ For road surface: Check and determine the volume and extent of damage: Potholes, gnawing toads, cracks, depressions, rubber Note that at the bridgehead road sections, the culverts are often subsided locally.
+ For the drainage system: Check the drainage condition at the sluices, the level of sand deposition in the upstream sluices, downstream sluice gates and in the culverts; damage of sewer pipes, slabs, joints, head walls, wing walls, sluice yards (especially downstream culvert yards or scour ).
+ For the road signaling system: Check the quantity and technical condition (markers, signs,convex mirrors, soft medians )
Construction of Road Furniture
+ Road interior system is especially important, it ensures safety for road users.
+ The current status of the route section has a winding route with many curves with small lying radius and large turning angle The contractor commits to strictly comply with labor and traffic safety measures throughout the construction process Types of construction site signs, barriers, baries, mobile soft medians are installed in the correct size, color, and reflectivity according to regulations.
Step 1: Gather supplies and equipment to the construction site, arrange equipment to ensure traffic safety;
Step 2: Construction and installation of baries, signs to prevent construction lanes of 1/2 road surface;
Step 3: Dismantle old signs that are faded, peeling, signs, signposts that are warped, dented, inappropriately sized, dig foundation pits at positions where new pillars are replaced.
Step 4: Clean, repaint the sign post, re-glue the new reflective sign according to the standards.
Step 5: Install new signs and reflective stickers.
Step 6: Finishing and curing concrete according to regulations.
Step 7: Change lanes to finish the rest (follow the steps above)
The road furniture after installation must be checked and accepted by the engineer.
Demolition of Detour Road
The Detour road will be demolished after the new bridge is built and put into use.
The process of demolishing the temporary road will be the opposite of the construction process, including the following works:
+ Demolition of road surface structure.
+ Digging the roadbed + Dismantling structures on the road + Clean up, return the ground
Demolition work will be done carefully step by step, absolutely ensuring safety during construction
QUALITY CONTROL
Genaral
+ QC Engineer shall inspect all work to ensure compliance to the requirement of Specification and Drawings.
+ Survey Engineer shall inspect the work of setting out to ensure the dimension of section is right.
+ Strict control of materials according to specifications and construction equipment.
+ Strict control spraying material thickness, speed compaction, compaction times.
+ The Contractor shall designate a competent and experienced technician to be incharge of operations at the site and to be responsible for the quality control of thework including, but not limited to, the following:
Tolerances Control
- Thickness of Pavement Layers: The average of thickness of any pavement layer measured at five points in any length of 100 m, shall not be less than 100 % nor more than 120 % of the thickness specified or ordered by the Engineer In addition, the thickness of any pavement layer measured at any point shall not be less than 98 % nor more than 125 % of the thickness specified or ordered by the Engineer.
- Surface Regularity: The surface regularity of pavement layers and the formation shall be tested at points decided by the Engineer with a rigid, steel straightedge 3 m long placed parallel to or at right angles to the centreline of the road The maximum allowable deviation of the surface below the straightedge shall be as given in table below.
Tolerances on Earthworks, Pavement and Bituminous Courses Description
- Cutting and Embankment Slopes: In the final trimmed slope of cuttings a tolerance of + 0.25 will be permitted, i.e if a slope of 1 in 2 is specified, the acceptable slope shall not be greater than 1 in 2 nor less than 1 in 2.25 In the final trimmed slopes of embankments, a tolerance of +0.25 will be permitted, i.e if the specified slope is 1 in 2, the acceptable slope shall not be greater than 1 in 2 nor less than 1 in 2.25.
- Width of Cuttings and Embankments: The tolerance permitted in the width of the bottom of cuttings shall be 200 mm between the center line of the road and the toe of the cutting slope The width of embankments measured as the horizontal distance from the center line of the road to the top of the embankment shall not be less than that shown on the Drawings or more than that shown on the Drawings plus 0.25 m.
- Depth of Side Drains: The depth of side drains measured as the vertical height difference from the center line of the finished pavement and the invert of the side drain shall not be less than that shown on the Drawings nor more than that shown on the Drawings plus 0.15 m. b) Structures
- Concrete Works: The construction tolerances for concrete works are as specified in sub-clause 5.1.5.16 of Specifications.
- Reinforcement: The tolerances on the manufacture and supply of reinforcing steel are determined against theoretical weights and are as indicated in Table below.
- Reinforcing bars are evaluated on the basis of nominal weights In no case shall the overweight of any bar or lot of bars be the cause of rejection.
- The term “Lot” means all bars of the same nominal weight per linear meter contained in an individual shipping release or shipping order.
Reinforcement: (As Per AASHTO M-31) Diameter of Bars Lot under Individual Bar under
Sampling and Testing Frequency
Material Test Designation Sampling and
(Lab) or Relative Density D-7049 (ASTM) 1 per 1,000 m Field Density AASHTO T-191 5 per 2,000 cu-m 2.6.3.3
Material Test Designation Sampling and Testing Reference
3 per Source plus 1 per 1000 cu-m 3.1.2.2
3 per Source plus as required based on visual observation 3.1.2.2
3 per Source plus as required based on variation in gradation.
3 per Source plus 1 per 500 cu-m 3.1.2.2
5 per layer per 2,000 Sq.m laid 3 min per layer if less than 2,000 Sq.m laid.
Material Test Designation Sampling and Testing
Gradation AASHTO T-27 2 per Stockpile plus 1 per 1,000 cu-m 5.1.3.4
Unit Wt AASHTO T-19 1 per Source plus 1 per 1,000 cu-m
For use in preparation of mix design
Specific Gravity AASHTO T-85 2 per Source plus 1 per 500 cu-m
For use in preparation of mix design
Absorption AASHTO T-85 1 per Source plus 1 per 500 cu-m
For use in preparation of mix design
Abrasion AASHTO T-96 1 per Source plus 1 per 500 cu-m 5.1.3.4
Soundness AASHTO-104 1 per Source plus 1 per 500 cu-m 5.1.3.4
1 per Source plus 1 per 500 cu-m 5.1.3.4
Gradation AASHTO M-6 2 per Stockpile plus 1 per 800 cu-m 5.1.3.5
Unit Wt AASHTO T-19 1 per Source plus 1 per 800 cu-m
For use in preparation of mix design
Specific Gravity AASHTO T-84 2 per Source plus 1 per 800 cu-m
For use in preparation of mix design
Absorption AASHTO T-84 1 per Source plus 1 per 800 cu-m
For use in preparation of mix design
Organic Impurities AASHTO T-21 1 per Source plus 1 per 800 cu-m 5.1.3.5
Soundness AASHTO-104 1 per Source plus 1 per 800 cu-m 5.1.3.5
Deleterious Substance AASHTO M-6 1 per Source plus 1 per 800 cu-m 5.1.3.5
Petrographic - 1 per Source plus 1 per 800 cu-m
131 1 per Lot or 1000 bags 5.1.3.1 Mortar
AASHTO T- 132 1 per Lot or 1000 bags 5.1.3.1 Yield Test for
Water Chemical Test AASHTO T-26 1 per source 5.1.3.2
1-3 batches: every batch 4-10 batches: 3 samples 11-20 batches: 4 samples>20 batches:
4 cylinders per 5 cu-m or part thereof
Material Test Designation Sampling and Testing
Reinforcing Bar Tensile Strength AASHTO M 31M 1 Sample per 10 tonnes 5.2.2.8
TRAFFIC SAFETY CONTROL
Traffic Management Plan
Traffic Management Plan to ensure safety of local communities from construction traffic A satisfactory traffic arrangement and reasonable dispersion measures shall be made to reduce the interference of construction to the traffic to ensure traffic safety in accordance with the characteristics of the works. a) 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. b) 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 six 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. c) Traffic Control of Blocked Sections
- For construction personnel in accordance with the safety regulations for construction The reflective working clothes and safety helmets 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. 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
For safe equipment operation, skilled operators are mandatory, with new operators undergoing skills tests prior to job acceptance Preventive maintenance checks are crucial before operation, and stability inspections of work areas and equipment foundations are essential, especially for cranes' outriggers and track pads Additionally, electrocution prevention measures are paramount for workplace safety.
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 Substructure work 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.
- 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. 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 near 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 of a flood frequency with P = 10% 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. d) Waste management
- The Contractor shall be responsible for the management of waste materials and waste in general arising during construction of the Works Management shall include the control of wastes on site and in temporary off-site areas, mitigation measures to minimize waste or redress any problems that arise from waste associated with the works and the collection and removal of waste materials from site and disposal to an approved disposal area
- Waste materials shall be all materials designated as waste or as surplus material for disposal as detailed in the specification; all waste materials incidental to the construction of the works including but not limited to oils, fuels, used formwork, temporary containers and packaging, excess concrete, and bituminous materials, etc and all waste arising from the Contractor’s offices and accommodation
- The contractor should properly treat human wastes from construction camps, accommodation, workshops, and offices To avoid contamination of the site the Contractor shall install mobile toilets at temporary site offices and fixed construction locations such as bridge sites Public rubbish bins should also be installed at the site office and temporary office locations.
- All solid wastes shall be collected, sorted out and disposed of to a properly designated disposal area Prior to the start of construction, the Contractor shall determine the location of suitable disposal areas approved by the relevant local authorities The Contractor shall submit all such areas to the Engineer for his acceptance together with copies of all relevant permits and approvals by such local authorities.