道路升级改造 施工方案 英文版.doc

1. GeneralThe scope of works in the project includes:(a) General(b) Setting out(c) Drainage Works (Including lining the trapezoidal drains with concrete or masonry) (d) Earthworks ( Grading, Forming , Embankment construction and Re-gravelling)(e) Road Paving and Surface sealing(f) Concrete works(g) Road Furniture The scope of works include upgrading of the gravel road to bituminous surface dressing and drainage works. We carried out the site inspection conducted by the Client and we are very familiar with the site conditions as relates to these works.2. Project AdministrationWe shall provide, maintain and subsequently remove temporary office, sanitary arrangements, store, workshop and everything necessary for the completion of the works. The site office will be provided with all the necessary facilities required including on- site test equipment to test compaction density and survey equipment to ensure that the works done are to specification. At mobilization, we will move all the necessary equipment, personnel and materials to site. This process will take only a month from the date of the commencement order.We shall employ female staff as well and shall be paid no less than the government gazette requirement for wages.The Consortium will provide a Contract Manager on the project who will make sure that all resources are available to the Project Staff for timely execution of the works.We shall have a Site Agent/Engineer whose duties shall include but not restricted to; programming of the works, progressing and co-ordinating all the works. He will also be responsible for the following:· All of the Contractors design (where appropriate)· Construction of all road and drainage works· Ensuring that all works complied with relevant standard and environment requirement. All correspondence and communication between the Employer and the Contractor, the Engineer and the Contractor shall be directed through the Contract Manager. Our proposed project organization chart is attached.1 3. Traffic ManagementA traffic Management plan will be formulated to minimize disruption of traffic flow as works progress. Alternative routes shall be opened up for motorist so as not disrupt works as well as inconvenience the motorists. We will endeavor to complete one or two roads at a time before moving to other roads so that traffic flow in town is not disrupted. Once one road is completed, it will be opened to traffic to restore the flow.4. Site PreparationClearing shall consist of removal of grubbing all vegetation on the roads including disposal of all material resulting from the clearing and grubbing as directed by the supervising engineer.Only the trees within the right of way which may fall on the carriageway or block the drainage system, or block sight lines shall be removed. 5. Method StatementKindly refer to the following Construction Sequence of Main Project: 2 5.1 Repeating SurveyAccording to the traverse points and elevation offered by supervising engineer, repeating survey are required by means of total station instrument, involved control pile to be set every 500m along the line. All the project teams shall add piles in accordance with control pile approved by consulting engineering; test、layout centre pile and section pile, 20m in a line segment and 10m in a curve segment, or set it as per requirements of consulting engineer, while test、layout the location of bridge and culvert.As per survey data outside, construction drawing shall be designed by means of software, including dimension of section、form of structure, which shall be3conducted after approved by consulting engineer.5.2 Earthwork & Stonework Excavation and Treatment1、Earthwork Excavation: Excavator or bulldozer will be used to removed gravelly soil. Filling materials for roadbed will be delivered to the segment of filling within economical distance after the approval of consulting engineer, and the remaining to be delivered to spoil ground specified (or approved) by consulting engineer. While repairing and compacting for existing roadbed, the bench excavation is applied in accordance with different types of excavation or filling. The steps and roadbed shall be compacted together, and the thickness is not less than 150mm. After confirmed by supervising engineer, if the excavated materials can be reused, shall be stacked on specified location, and crushed to extent size as required.2. Stonework Excavation: A mall amount of excavation for weathered stone will use excavator, however, blasting construction will be used for a large area of stonework excavation.5.3 Earthwork Construction for RoadbedEarthwork Construction for Roadbed will be conducted as per the following procedures “Three Stages、Four Segments、Eight Technology Process”, as follows:Three Stages: preparation stage、construction stage、completion stage; Four Segments: filling area、leveling area、rolling area、test area;Eight Technology Process: construction preparation、basement treatment、filling in layer、paving and leveling、watering and drying、rolling and compacting、test and signature、roadbed renovation.4 5(1) Preparation WorkEstablishment of temporary pavement , arrangement for personnel、machinery entering the arena、waterproof & drainage facilities.Selection of Materials and Compacting Test:Compacting test shall be conducted to ensure appropriate technological parameter used in construction stage, approved by supervision. Detailed content: selection of suitable compacting machinery；selection of the best fill depth、the best water content; selection of reasonable compaction times; confirmation of earth volume in rate of change、coefficient of loose laying; confirmation of reasonable technological process.Survey and Positioning:Set permanent plane and vertical control point, setting out centre line by surveying in the construction area, set the location for toes of roadbed、trench and excavate it as per design position.Verifying the Geological Survey:Detailed design documents about engineering geology、hydrology and geological basis, practical situation of this project, involved the similarly construction experience of foundation, the following above items are required prior to commencement of work.It is necessary to carry out additional exploration, to inspect and calibrate geological data based on the original geological data. Exploration will be conducted by the methods of static test and vane shear test.(2) Base of Foundation TreatmentSurface Clearing: Prior to commencement of work, attachments planted on the land、grass、tree root and other clutters shall be removed, while the thickness of clearing is not less than 0.15m, arrangement for drainage facilities as well. If base of foundation is cultivated land or loosen soil, the original surface shall be rolled and compacted, while the thickness of loosen soil is less than 0.3m; otherwise, the thickness of loosen soil is more than 60.3m, which shall be loosened、crushed、 rolled & compacted based on practical situation; after that, bulldozer will be used to remove humus soil and deliver to spoil ground by dump truck. The pits and caves due to cleaning shall be backfilled by using materials (crushed stone) with better water permeability, and shall be compacted as required. After base of foundation cleaning, leveling is required by means of excavator and road grader, while rolling and compaction is required by means of heavy-duty vibratory roller. Based on different surface soil, the test shall be conducted to base of foundation, and filling is required after testing qualified.Quality Inspection of Roadbed Treatment: Surface on base of foundation after foreign matter cleaning, if the bearing capacity of natural foundation is less than design requirement, base of foundation shall be compacted by vibratory roller, with compactness 95%.(3) Filling in LayersAdhere to the policy “Three Lines、Four Levels” during construction. Three lines, namely centre line、side boundary; set a red flag every 20m, to confirm the control point of centre line and side boundary. Four levels, namely thickness、compactness、camber、smoothness; the thickness of roadbed in layers shall be controlled to ensure the compactness in each layer; strictly control of compactness of filling, to ensure the quality of roadbed and the settlement are not exceeded; control of camber is required to discharge rainwater in time; control of smoothness to ensure uniform thickness of roadbed after rolling and no water accumulation on roadbed with the rainfall. Filling and compaction will conducted in longitudinal layer of cross section, and then divided into some construction sites every 200m or between two structures. Thickness in layer shall be controlled strictly on the basis of test data. A group of elevation point set on embankment every 20m; however, the thickness is not more than 30cm, while the thickness is not less than 20cm, and the maximum thickness of virtual layer can not exceed 35cm. Filling exceed 4050cm in thickness along the roadbed every time, so as to compact, 7to ensure enough compactness on border of embankment after completion. In the area of backfill soil, the distance between every mound shall be based on the capacity of dump truck, so as to balance thickness in layers during leveling.5.4 Imperfection Mending for Existing Road1. PreparationPrior to commencement of work, put safety signs on construction sections and close half range of the road, moreover, put speed limit sign on another range of the road, which shall be in the charge of a specially-assigned person. Construction activities shall be conducted in the premise of safe operation on highway.For excavated section of highway as required by supervising engineer or on construction drawing, the border excavated firstly is required, with sign marked on highway. Mechanical equipment、auxiliary tool and personnel shall be confirmed in accordance with different areas and depth.2. ExcavationChoose suitable tools in accordance with excavation border and depth, assisted with manual excavation, and reserve bench excavation. While discrepancy exists between construction site and construction drawing during excavation, contact with supervising engineer to ensure the best method statement with high quality. Excavation materials, which can be utilized again, shall be stacked to the specified place for cycling; otherwise, delivered to spoil ground.3. MendingBase of foundation treatment shall be conducted firstly for excavated road. After achieving smoothness and compactness as required, back fill in layers as per design requirement. Filling material and thickness shall be in compliance with required specification, moreover, foundation and selected layer shall be back-filled by using qualified gravelly soil; stabilized gravelly soil will be used for base back-filling. After back-filling and leveling finished, compaction shall 8be conducted on time, and electric hammer used to compact potholes and corners, with curing of watering. Stabilized gravelly soil can be mixed on the site for the area of mending, however, the method of central mixing can be used for the potholes, and finished materials delivered to back-filling. Not exceed the initial setting time of cement during construction.5.5 Base ConstructionConstruction Technology Chart for Cement Stabilized Soil: 1. PreparationPreparation for Bearing Layer: Before cement and gravel spreading, compactness、smoothness and dimension of foundation or base course shall be checked complied with specification as required.(1) Survey: Recover centre line on base or roadbed, one pile will be set every 15-20m on straight segment, and another pile set every 10-15m on curve segment, moreover, indication pile set on both sides of shoulder. Design elevation of cement and gravel shall be marked on indication pile for surveying.(2) Materials Preparation: Materials used for construction activities shall be taken from qualified borrow pit, meet the specification as required. Before9materials preparation, tree、root、grass piece and miscellaneous soil shall be cleared. Collect from top to bottom is required in collecting area, to avoid unqualified soil mixing into prepared materials, exclusive unqualified aggregate.(3) Quantity of Materials: The quantity of aggregate shall be counted in accordance with design width、thickness and density. The distance between every materials stacked on site shall be counted as per aggregate and tonnage of truck. Count the cement dosage of per square meter and the distance between every pocket of cement as per thickness of cement gravel、dry density and cement dosage.2. Aggregate Transportation and Spreading(1) Laying Coefficient: The coefficient of initial loose-laying shall be chosen from1.30 to 1.35, and with adjustment after compaction.(2) After aggregate transporting, watering for the constructing surface, and the quantity of every truck are required the same.(3) Leveling in a extent area by grader, with smoothness surface, moreover, set road camber as required.(4) The cars are prohibited from passing on the aggregate, except for watering car、grader and roller.3. Mixing(1) Concrete Spreading: 6-8T rollers with double wheels will be used to roll aggregate, to make smoothness. Some measures of rain-roof shall be taken for cement and aggregate(2) Dry Mixing: Mixing machine will be used for stabilized soil, the depth shall reach the stable layer, with designated person checked.(3) Watering and Wet Materials: If the water content is not enough during dry mixing, supplement of water is required. During watering, the length shall exceed 2 meters, and the water tank shall not turn around or stay, so as to ensure uniform watering. Mixing machine shall be followed by watering car to mix materials. Regular inspection for water content of mixture is required 10during watering and mixing.4. Reforming and Rolling(1) Reforming: After mixing evenly, leveling and reforming are required firstly by grader. In straight line, scraped by grader from both side of road; in curve line, scraped from interior to exterior, if necessary, the second scraped is required; rolled twice by roller is required.(2) Rolling: After reforming. While the water content of mixture is in good condition within the area of 1%, 12T capacity of roller、vibratory roller shall be adopted to roll on road, until meet the required density. Any unqualified thing, the rolling work is required again.5. Joint and U-turn Treatment(1) The method of lap joint shall be used for the simultaneous construction for joint.5-8 meters shall be reserved after mixing and reforming during initial construction. After that, the part not rolled shall be mixed with some cement, then rolle