Pk1 03 earth work bg (giang) szk as080921 in

DIVISION - EARTHWORKS Table of Contents DIVISION EARTH WORKS TABLE OF CONTENTS 03000 – SCOPE OF WORKS AND GENERAL…………………………………….…6 03100 - COMMON EXCAVATION ………………………………………………… 11 03200 - STRUCTURAL EXCAVATION……………………………………………….19 03300 - BORROW MATERIAL …………………………………………………………30 03400 - EMBANKMENT CONSTRUCTION …………………………………………36 03500 – SOFT SOIL IMPROVEMENT MEASURES …………………………………58 GENERAL SPECIFICATIONS 03300 of 84 DIVISION - EARTHWORKS Table of Contents TABLE OF CONTENTS SECTION 03000 – SCOPE OF WORK AND GENERAL SCOPE OF WORK AND GENERAL scope GENERAL 2.1 SOIL INFORMATION 2.2 CLASSES OF THE WORK 2.3 HORIZONTAL AND VERTICAL ALIGNMENT 2.4 QUANTITIES .7 2.5 METHOD OF MEASUREMENT .7 2.6 REMOVAL OF EXISTING OBSTRUCTIONS .7 2.7 REMOVAL OR DIVERSION OF WATER 2.8 USE AND DISPOSAL OF EXCAVATED MATERIAL 2.9 DITCHES 2.10 RELOCATION OF STREAM CHANNELS 2.11 LOOSE EARTH OR ROCK, LANSLIDES, BENCHES, FLATTENUNG OF SLOPE 2.12 FILLING EXISTING WATERCOURSES 2.13 RATE OF SETTLEMENT OF EMBANKMENT SECTION 03100 - common excavation 12 Description 12 CONSTRUCTION REQUIREMENTS 12 2.1 GENERAL .12 2.2 Classification of Excavation 12 2.3 Top soil Protection 18 2.4 Use of Excavated Material 18 2.5 Dimensional Tolerances 18 SECTION 03200 - Structural Excavation 19 Description 20 Work Requirements 21 2.1 Structural Excavation Classification 21 2.2 Groundwater 20 2.3 Preservation of Channel 22 2.4 Excavation .22 2.5 2.6 Blinding Stone .24 Backfilling and Structural Embanking 254 GENERAL SPECIFICATIONS 03200 of 84 DIVISION - EARTHWORKS Table of Contents 2.6.1 2.6.2 2.7 Granular Backfilling 25 Permeable Backfill .256 Special Cofferdams 267 Method of Measurement 28 3.1 Quantity Measurement 28 3.2 Basis of Payment 289 SECTION 03300 - Borrow material 310 Description 31 Material Requirements 31 2.1 Submittals for Materials 31 2.1.1 Shop and Working Drawings and Schedules 31 2.2.2 Samples and Testing 32 2.2 Borrow Material for Embankment Construction 32 Construction Requirements 33 Measurement and Payment .33 4.1 Method of Measurement 34 4.2 Basis of Payment 35 SECTION 03400 - EMBANKMENT CONSTRUCTION 36 Description 38 1.1 Embankment Construction .38 1.2 Setting Out the Work, Staking and Surveying .38 Material Requirements 38 2.1 Reference Standards 38 2.2 Setting Out the Work, Staking and Surveying .39 2.3 Submittals 39 2.3.1 Shop and Working Drawings and Schedules 39 2.3.2 Schedule for Setting the Work, Staking and Surveying 40 2.4 Materials .40 2.5 Subgrade 30 cm Layer (K≥ 98%) 98%) 41 2.6 Layers Below Subgrade .41 2.7 Rock Fragments and Boulders .41 2.8 Cohesive Slope Material 41 2.9 Re-Use from “Embankment for Settlement” (EfS) and Counterweight 42 2.10 Use of Suitable Materials from Site Excavation .42 Construction Requirements 42 3.1 General 42 3.2 Setting Out the Work, Staking and Surveying .43 3.2.1 Basic Requirements on Surveying and Staking 43 3.2.2 Construction Requirements on Surveying and Staking 44 3.2.3 Equipment and Personnel and Test .47 3.3 Basic Requirements for Embankment Construction .47 GENERAL SPECIFICATIONS 03200 of 84 DIVISION - EARTHWORKS Table of Contents 3.4 Method of Construction 47 3.5 Rock Fill .49 3.6 Compaction Trial 49 3.7 Compaction of Embankment Material .49 3.8 Compaction Equipment .52 3.9 Construction of Control Strips and Determination of Target Density 52 3.10 Protection of Roadbed and Slope During Construction 53 3.11 Protection of Structures 53 3.12 Rounding and Warping Slopes 53 3.13 Finishing Roadbed and Slopes 54 3.14 Dimensional Tolerances after compaction 54 3.15 Complementary Requirements for Subgrade Construction .54 Measurement and Payment .55 4.1 Method of Measurement 55 4.2 Basis of Payment 56 SECTION 03500 - SOFT SOIL IMPROVEMENT MEASURE 58 Description 60 1.1 Vertical Drainage System 60 1.2 Embankment for Settlement (EfS) .60 1.3 Embankment Instrumentation and Monitoring 61 1.4 Subsoil Investigation 61 1.5 Sub-Drainage System 61 Material Requirements 61 2.1 Reference Standards 61 2.2 Submittals 62 2.2.1 Shop and Working Drawings and Schedules 62 2.2.2 Other Submittals 62 2.3 General Requirement for Materials 63 2.4 Materials for the Vertical Drainage System 64 2.4.1 Coarse Sand Blanket (CSB) 64 2.4.2 Prefabricated Vertical Drain (PVD) 64 2.4.3 Separation-Geotextile Filter Fabric 66 2.5 Embankment Instrumentation .66 2.6 Observation Wells 67 Construction Requirements 67 3.1 Coarse Sand Blanket .67 3.2 Prefabricated Vertical Drains (PVDs) 68 3.3 Separation Geotextile Filter Fabric 69 3.4 Counterweight Embankment and Embankment for Settlement (EfS) 3.5 Removal of EfS 70 3.6 Embankment Instrumentation and Monitoring 71 3.6.1 Surface Settlement Plates (SSP) 71 GENERAL SPECIFICATIONS 03200 of 84 DIVISION - EARTHWORKS 3.6.2 3.6.3 3.7 3.7.1 3.7.2 4.1 4.2 Table of Contents Alignment Wood Stakes 72 Recording and Monitoring 72 Stability and Settlement Monitoring Surveys 75 Geotechnical Engineering Specialists 75 Grouting of Pipes for SSP and Observation Wells 76 Measurement and Payment .77 Method of Measurement 77 Basis Payment .78 GENERAL SPECIFICATIONS 03200 of 84 DIVISION - EARTHWORKS Scope of Work and General- Section 03000 SECTION 03000 – SCOPE OF WORK AND GENERAL SCOPE Road earthwork shall consist of all necessary work for the excavation and placing or disposal of earth or rock or other material from or to the roadway or adjacent thereto, for construction of waterways, ditches, laybys and approaches, for the removal of unsuitable material, the removal of landslides, all in accordance with the lines, grades, cross-sections shown on the Drawings or as established by the Engineer GENERAL 2.1 SOIL INFORMATION a) Any information of the properties of the soil that may be shown on the Drawings or obtained by the Contractor as a result of discussion with the Engineer shall alone not be considered as a sufficient basis for the Contractor's Bid Prices b) The Contractor is responsible for his interpretation of information supplied by the Employer and shall visit the Site and possible Borrow Pits prior to making his Bid and shall ascertain the nature of the soil, its quantity, locations, and suitability to meet the specified requirements 2.2 CLASSES OF THE WORK a) This work will be divided into the following classes, which are hereinafter described in detail under separate headings: (b) 03100 Common Excavation 03200 Structural Excavation 03300 Borrow Material 03400 Embankment and Areas of Fill 03500 Soft Soil Improvement Measures All road earthwork shall be carried out in accordance with the Specifications for the classes as named above, and the specifications for other work items involved, and in conformity with the lines, grades, sections and dimensions, shown on the Drawings or required by the Engineer 2.3 HORIZONTAL AND VERTICAL ALIGNMENT The Engineer will supply the Contractor with the locations of the Points of Intersection of Tangents and Grade Lines The Drawings will indicate the properties of horizontal and vertical curves, together with the rates of super-elevation where required The Contractor shall prepare cross-sections based upon the above properties, secure the Engineer's approval of his cross-sections and stake out before proceeding with construction If, in the opinion of the Engineer, any modification of the line or grade is advisable, either before or after stake-out, the Engineer will issue detailed instructions GENERAL SPECIFICATIONS 03300 of 84 DIVISION - EARTHWORKS Scope of Work and General- Section 03000 to the Contractor for such modifications and the Contractor shall revise the stake-out for further approval These requirements shall be met without additional payment and all costs thereof shall be included in the Bid Prices for pay items under the Contract 2.4 QUANTITIES a) The quantities of the various classes of excavation and embankment to be measured for payment under the Contract will be based on the lines shown on the approved profiles and cross-sections or as instructed by the Engineer The Engineer may decide the angle of the slope of cut and fill or the formation of benches in the slopes as the work proceeds on the basis of his evaluation of the soil characteristics b) The cross-sections will form the basis of the earthworks calculations but they will be supplemented by such site measurements as are necessary to accurately determine the quantity for each pay item In particular, the procedures described in Clause 2.13 – Settlement of Embankment (Section 03000) will be adopted to determine any additional materials which have been placed by the Contractor to compensate for settlement of the under-lying soil Where the Engineer orders the placing of temporary filling such as above future abutments, this will be paid as Borrow and Common Excavation or such other pay items as are relevant and applicable The actual lines of the cut and fill as made shall be duly measured and recorded by the Contractor The Engineer will check these records and will approve the measurements, if correct, as a basis of payment Excavation and fill in excess of the approved cross-section will not be paid for c) Suitable excavated material surplus to the requirements of Section 03200 - Structure Excavation - of these Specifications, shall be considered as available for incorporation in fill areas, and should be stockpiled if not required at the time of excavation d) Excess excavation shall be backfilled, as directed by the Engineer, with suitable material without extra payment 2.5 METHOF OF MEASUREMENT The quantities of earthwork to be paid for shall be the number of cubic metres of material measured and computed by calculations incorporating the average end-area method, except where the error may exceed plus or minus five percent as compared with the primordial formula, in which case the Engineer will authorize the use of the more accurate method However, the Contractor shall request such authority before he submits his quantities for approval Quantities measured on the average end-area basis, once they have been submitted and approved, shall not be subject to review for the purpose of applying a more accurate method 2.6 REMOVAL OF EXISTING OBSTRUCTIONS a) The Bid Prices for the classes of excavation shall include the cost of removal of all material, regardless of its nature, encountered within the approved limits for excavation, including the removal and disposal, as required by the Engineer, of sections of existing brick, GENERAL SPECIFICATIONS 03300 of 84 DIVISION - EARTHWORKS Scope of Work and General- Section 03000 stone, concrete or masonry, rock boulders or fragments of old pavements encountered during earthwork b) Only boulders or bricks of masonry of individual size greater than cubic metre, or sections of old pavement of an individual size greater than 10 cubic metres will be paid for under the respective pay item from Section 02200 – Demolition, Removal of Existing Structures and Obstruction of these Specifications 2.7 REMOVAL OR DIVERSION OF WATER a) Removal or Diversion of Water shall not be paid for separately, but shall be deemed to be included in related work under Section - Road Earthwork b) The Contractor shall provide necessary facilities for de-watering, and for draining or diverting water-courses when necessary for the execution and protection of the Work or where required by the Engineer c) The Contractor shall provide such temporary or permanent drainage outlet ditches as may be necessary to effect proper drainage before rain is to be expected Payment will only be made for the permanent work 2.8 USE AND DISPOSAL OF EXCAVATED MATERIAL All surplus suitable material excavated within the limit and scope of the Project shall, unless provision is expressly made to the contrary in these Specifications, be used in the most effective manner for the formation of the embankment Any material surplus to these requirements, or any material declared in writing by the Engineer to be unsuitable, shall be disposed of by the Contractor outside the right-of-way or as directed by the Engineer in accordance with the provisions of these Specifications, and shall be considered as Waste, which shall be subject to the provisions of Clause 4.2.3 – Unsuitable material under Section 03100 – Common excavation 2.9 DITCHES a) The Contractor shall construct channels, side and interception ditches, inlet and outlet ditches as shown on the Drawings or where ordered by the Engineer, whether for temporary or permanent drainage In order to keep water away from the embankment, Sub-grade, sub-base, and/or base during construction, the Contractor shall at all times ensure adequate drainage is operative before work is begun on the embankment and pavement structure He shall clean and trim all such drainage ditches from time to time so that there may be a free flow of water throughout the whole Construction Period and Period of Warranty b) Damage to the work attributable to wetting through failure to provide adequate drainage will result in an order to repair the damage at the Contractor's expense Ditches shall first be trimmed short of the approved cross-sections, and final trimming, including the repair of any damage that may have been done during the construction work, shall be carried out after the completion of the construction work and shall be a condition for final approval and acceptance GENERAL SPECIFICATIONS 03300 of 84 DIVISION - EARTHWORKS Scope of Work and General- Section 03000 c) Irrigation of areas on which earthworks are to be executed shall have been halted at least two months in advance of the construction All surface water shall be drained off and temporary and permanent ditches constructed in good time to allow the area to dry out 2.10 RELOCATION OF STREAM CHANNELS Where indicated on the Drawings or where required by the Engineer, the Contractor shall take cross-sections of existing stream channels and, in collaboration with the Engineer, mark them with details of the excavation required for the relocation of the stream channel The Contractor shall also take levels to allow the profile levels of box culverts and their extensions to be accurately fixed by the Engineer Work shall not proceed without approval of the marked cross-sections by the Engineer The work of stream channel excavation shall be considered as Common Excavation and paid for at the Contract unit prices for this item, subject to the provisions of Clause 4.2.1 – Common Soil Excavation under Section 03100 – Common Excavation 2.11 LOOSE EARTH OR ROCK, LANSLIDES, BENCHES, FLATTENUNG OF SLOPE a) Loose earth or loose rock shall be removed from slopes when required by the Engineer He may also order the removal of material resulting from landslides, the construction of benches in or above the cut slopes, or, where in his opinion the slope, after cutting, shows signs of instability, the flattening of the slope b) Performance of this work under the contract is not payable directly but shall be considered as a subsidiary obligation of the Contractor covered under the unit rate for Common Excavation or Borrow Material 2.12 FILLING EXISTING WATERCOURSES Where watercourses have to be diverted from sites of embankments or other works, the original channels shall be cleared of all vegetable growths and soft deposits and carefully filled with suitable materials deposited and compacted as specified in Section 03400 - Embankment and Areas of Fill 2.13 RATE OF SETTLEMENT OF EMBANKMENT a) In areas of sub-soils with low bearing capacity as shown elsewhere in these documents the rate of settlement shall be monitored and the rate of placing of fill material carefully controlled At the direction of the Engineer and in accordance with the provisions of Section 06920 - Test Drilling - the Contractor may be required to undertake investigations of existing soft ground conditions along the Project alignment These will be used to confirm the results of the existing soil investigations and to support the Engineer in his determination of areas, other than those already identified in the Drawings, that may require special controls on the rate of settlement b) Unless otherwise proposed by the Contractor and approved by the Engineer, this will be done by means of settlement plates installed as shown on the drawings or as instructed by the Engineer The plates shall GENERAL SPECIFICATIONS 03300 of 84 DIVISION - EARTHWORKS Scope of Work and General- Section 03000 be installed on the existing sub-soil before placing any embankment and a 30cm thick layer of sand material shall be placed on the settlement plate base to eliminate bedding errors The Engineer will inspect the completed installation and together with the Contractor will take initial elevations on the top of the base plate and the top of the rod As embankment construction proceeds the rods and their protection pipes shall be extended interval 100 cm extensions as necessary c) As an additional check on the stability of embankments, the Contractor will install line and level stakes to the sides of embankments at locations shown on the drawings or instructed by the Engineer The number of these stakes and their spacing shall also be shown on the drawings The Contractor will be responsible for arranging with the landowners for regular access to the monitoring stakes and if necessary paying any expenses arising from this access The Contractor, under the supervision of the Engineer, shall monitor the settlement and stability until the issue of Defect Liability Certificate, and from time to time submit reports and monitoring data to the Engineer for consideration and approval After the completion of the pavement or covering structures, the Engineer may instruct to monitor the settlement by controlling the elevation of the pavement or covering structures d) During the period of settlement the Engineer may instruct additional material to be placed at the toe of the embankment to improve stability Any such material may be removed after the settlement is complete and this work will be measured and paid for under the other Clauses of this Specification The site management control of the rate of material placing shall be such as to stay within the values of deformation of 1cm/day vertical movement and mm/day horizontal movement as specified in the Vietnamese Standard 22TCN 262-2000 e) Unless there is a pay item under Section 03400 - Embankment Construction, the work of installing, maintaining and monitoring the settlement monitoring devices will not be measured directly for payment but will be deemed to be included in the Contractors unit price for the material used in the embankment f) Where the Engineer has instructed the use of settlement plates to monitor the rate of embankment settlement, the measured total settlement will also be used to determine the additional material to be placed by the Contractor to compensate for the total amount of the settlement In areas where the rate of settlement is not critical in the formation of the embankment, the Engineer will not instruct the provision of settlement monitoring devices However, in such areas the Contractor may elect at his own expense to install approved settlement measurement devices Subject to the Engineer’s approval, measurements from these additional devices will be used in the calculation of the quantities of embankment as given in Clause 2.4 – Quantities under this Section-03000 GENERAL SPECIFICATIONS 03300 10 of 84