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Ou C & SP A Sin g 47 K # 0 9 Vie t 250 Dis t Em a r Project R YÊ & S Consul t A N CONSU L g apore offic e K allang Pud d 9 -07 The Cr e t nam office: Nguyen Di n t rict 3, Ho C h a il: span@s p R ef. No. 2 PRO P STRU C Ê U CẦ U t ants: L TANTS e : d ing Road, e scent @ Ka n h Chieu, W a h i Minh City p an-design. c 005 P OSED M C TUR A U KỸ T H llang, Singa p a rd 6 c om M AIN G A A L SP E H UẬT P p ore 34931 8 A TE FOR E CIFIC A P HẦN 8 PARKCI A TION KẾT C Is s TY ẤU s ued date: O O ctober 201 3 3 1 T A 1. 2. 3. A BLE OF C EARTH W CÔNG T Á JACK-IN CÔNG T Á CONCR E CÔNG T Á C ONTENT S W ORKS Á C ĐẤT CONCRE T Á C ÉP CỌ E TE Á C BÊ TÔ N S T E PILIN G C BÊ TÔ N N G G N G 3 25 40 2 EAR T CÔN G T HW O G TÁ C O RKS C ĐẤT 3 EARTHWORKS Page 1 EARTHWORKS 1.0 GENERAL CONDITIONS 1.1 The Contractor shall undertake thorough compaction of all perimeter and entrance areas where non-suspended ground slab has been specified. Similarly, all areas for internal roads construction shall be thoroughly compacted as specified herein. 2.0 GROUND PREPARATION FOR ROADS & GROUND SLABS 2.1 All unsuitable material evident on the surface shall be removed. Generally, this will be achieved by stripping off the top 500mm. The cleared site shall then be scarified to a minimum depth of 300mm. Any areas where visual examination reveals the presence of unsuitable material shall be excavated as necessary to remove such material. Any soft spots indicating underlaying pockets of unsuitable material shall also be excavated. 2.2 At all times during earthworks the surface shall be gently sloped to temporary ditches to enable surface water to run off. Any ponding evident after rain shall immediately be pumped dry and the area filled and compacted with suitable material. 3.0 DEFINITION AND CLASSIFICATION OF EARTHWORKS 3.1 The following definitions of earthworks materials shall apply to this Specification: 3.1.1 'Top soil' shall mean the top layer of soil that can support vegetation. 3.1.2 'Approved material' shall comprise all that which is acceptable in accordance with the Contract for use in the Works, and which is capable of being compacted in the manner specified in Clause 15 hereafter to form a stable fill. 3.1.3 'Unsuitable material' shall mean other than approved material and shall include: 3.1.3.1 Material from swamps; 3.1.3.2 Peat, logs, stumps and perishable materials; 3.1.3.3 Material susceptible to spontaneous combustion; 3.1.3.4 Soil of liquid limit exceeding 70 and/or plasticity index exceeding 35; 3.1.3.5 Material having an in-situ moisture content greater than the maximum permitted for such material in the Contract, unless otherwise permitted by the Engineer. 3.1.4 'Rock' shall mean hard material, whose geological nature is to be regarded as such and individual boulders exceeding 1.00 cubic m in size or other masses of hard material which necessitate tools for removal. 3.1.5 'Special filling material' shall mean 'approved material' but capable of passing a 75mm BS sieve. The fraction passing a 75mm BS sieve shall have the following characteristics: 3.1.5.1 Liquid limit not exceeding 35. 3.1.5.2 Plastically index not exceeding 12. 4 EARTHWORKS Page 2 3.1.5.3 Co-efficient of uniformity shall be greater than 10. 3.1.5.4 The percentage passing 75mm BS sieve shall be less than 20% by weight. 3.1.6 'Cohesive soil' includes clay with up to 20% of gravel and having a moisture content not less than the value of the plastic limit minus 4. 3.1.7 'Well-graded granular and dry cohesive soils' includes clays containing more than 20% of gravel and/or having a moisture content less than the value of plastic limit minus 4, well-graded sands and gravel with a uniformity coefficient exceeding 10. 3.1.8 'Uniformly-graded material' includes sands and gravel with a uniformity coefficient of 10 or less, and all silts. Any soil containing 80% or more of material in the particle size range 60 micrometres -2 mm will be regarded as silt for this purpose. 4.0 EARTHWORKS GENERALLY 4.1 The Contractor shall carry out all earthworks in such a manner as to prevent erosion or slips, shall limit working faces to safe slopes and height, and shall ensure that all surfaces have at all times sufficient gradients to enable them to shed water without causing erosion. 4.2 At the end of each day, all surfaces shall be left with no area that can retain water. If necessary, the Contractor shall provide and maintain temporary and approved surface or subsurface drainage system to ensure minimum delay in work progress due to wet weather. Alternatively, adequate means, such as covering all surfaces with polythene, shall be provided and maintained. 4.3 The Contractor shall provide and maintain all necessary temporary access roads and shall divert and reinstate permanent drainage system. All temporary roads shall be provided with drainage ditches over full length. 5.0 TRIAL HOLES 5.1 The Contractor shall be deemed to have satisfied himself as to conditions affecting execution of the Works by visiting and inspecting the Site of the proposed Works. He may be permitted to inspect the trial holes that have been made and any open excavations in connection with other works should such be in progress, and also to study any available drawings which might be of assistance. The Contractor must clearly understand that all information is given expressly without guarantee and he shall obtain his own information regarding the notices of the excavation, conditions peculiar to the Site, and all other matters affecting the proposed works, and he shall make provision in his rates to cover for the types of materials to be excavated. 6.0 EXCAVATION GENERALLY 6.1 Excavation shall be carried out to the dimension lines, levels, and slopes as indicated on the drawings. If the Contractor excavates deeper than the depths shown on the drawings or as instructed by the Engineer then he shall, at his own expense, fill in such excessive depths with lean mix concrete to the satisfaction of the Engineer. 6.2 The bottoms of all excavations shall be kept free from mud and water, trimmed clean, protected from the effects of weather and thoroughly compacted and consolidated in an 5 EARTHWORKS Page 3 approved manner and means, subject to the requirements as stipulated under Clause 15. 6.3 All soft or defective portions of soil below formation level shall be cut out and filled in with approved material well consolidated in layers of approved thickness. 6.4 No excavated approved material other than surplus to the requirements of the Contract shall be removed from the Site except on the direction or with the permission of the Engineer. Should the Contractor be permitted to remove approved material from the Site to suit his operation procedures, then he shall make good at his own expenses any consequent deficit of filling arising therefrom with approved material. 6.5 Where the excavation reveals a combination of approved and unsuitable materials the Contractor shall, unless otherwise agreed by the Engineer, carry out the excavation in such a manner that the approved materials are excavated separately for use in the Works without contamination by the unsuitable materials. 7.0 APPROVAL OF EXCAVATION 7.1 The Contractor shall report to the Engineer when secure bottoms have been obtained to the excavations and are ready to receive the concrete. Any concrete or other work put in before the excavations have been inspected and approved by the Engineer shall, if so directed, be removed and new work substituted in accordance with the Specification after the excavations have been approved, all at the Contractor's own expense. 8.0 CUTTINGS INCLUDING SLOPES 8.1 Unless otherwise specified or shown on the drawings, the top edges of cutting shall be neatly rounded to the dimensions shown on the drawings or as directed by the Engineer. Such work shall be deemed to be included in the Contractor's rate for cutting work. 8.2 Unless otherwise specified or shown on the drawings, slopes to cutting shall conform with the following: TABLE 1.1 : ALLOWABLE SLOPES IN CUTTINGS Material Slope (Horizontal to Vertical Rise) Sand Five to One 5:1 Loose Gravel or Clay One to One Half to One 1:1½:1 Shale or Similar Soft Rock One to One 1:1 Rock with Clay Seams Three Quarters to One ¾:1 Jointed Laminated or Soft Rock One Half to One ½:1 Massive Rock One Quarter to One ¼:1 Where shown on the drawings, slopes on the cross sections represent the estimated requirements for the expected types of materials and these slopes shall be subject to re-determination by the Engineer according to his assessment of the materials encountered. 6 EARTHWORKS Page 4 9.0 EXCAVATION OF FOUNDATION PITS AND TRENCHES 9.1 Where required by the nature of the materials to be excavated, the Contractor shall provide all necessary planking, strutting and shoring required to uphold the face of the excavation and any necessary stagings. The Contractor is responsible for the design, supply, fixing and removal of all planking and strutting required of supply, fixing and removal of all anticipated loadings and to ensure the safety of the workpeople and to prevent damage to any adjoining property. The Engineer may direct that such supports be left in position. 9.2 Alternatively, subject to the prior approval of the Engineer, the face of the excavation may be suitably battered. 9.3 Trenches and pits shall not be wider than is necessary for the efficient laying and jointing of pipes or for other works to be carried out. 9.4 The bottoms of all excavations shall be levelled carefully and stepped or benched horizontally as shown on the drawings. Any pockets of soft material or loose rock in the bottom of pits and trenches shall be removed and the resulting cavities and any large fissures filled with lean mix concrete. After the placing of any blinding concrete required by the Contract, no trimming of the side faces shall be carried out for 24 hours. 9.5 The Contractor shall make good with approved material or concrete as directed by the Engineer, the following : 9.5.1 Any excavation greater than the nett volume required for the Works as described in the Contract. 9.5.2 Any additional excavation at or below the bottom of foundations to remove material which the Contractor allows to become unsuitable. 9.6 No greater length of trench shall be opened at any one time than has been approved by the Engineer. All surplus spoil shall be removed immediately on excavation, and stacked spoil for filling shall be kept tidy at all times. 10.0 FILLING OF FOUNDATION PITS AND TRENCHES AND REMOVAL OF SUPPORTS 10.1 Unless otherwise shown on the drawings, or directed by the Engineer, all filling for this purpose shall consist of approved material, deposited and compacted by approved plant in accordance with Clause 15. Timber sheeting and other excavation supports shall be carefully removed as the filling proceeds except where such are required by the Contract to be left in position, but the removal of such supports will not relieve the Contractor of his responsibilities for the stability of the Works. 11.0 FOUNDATIONS OF FILL 11.1 Embankment construction shall include the preparation and compaction to the degree as specified under Clause 15, of the areas upon which embankments are to be placed, the placing and compacting of approved material within areas from which unsuitable material has been removed as specified hereunder, and the placing and compacting of embankment material in holes, pits, and other depressions within the foundation area. 11.2 Unless otherwise specified, the natural ground over which filling is to be placed shall be cleared of all loose boulders, grass, topsoil, bushes, trees, roots and other vegetation. If the Engineer considers that any underlying material is unstable or unsuitable, he may direct it to be removed and replaced with approved material. 7 EARTHWORKS Page 5 11.3 Any overhanging rock ledges or caves within the foundation area shall be removed before the placing of fill commences. 11.4 Where ground water or extensive seepage is encountered in the foundation area, and no special drainage arrangements are shown on the drawings, the Engineer may direct that suitable pipe drains be installed in the fill area, or that deep open drains be excavated clear of the fill. The Engineer will supply details of the work required, which will be reimbursed as an extra to the Contract. 11.5 The construction of any section of fill shall not be commenced until the foundation for that section has been approved by the Engineer. 12.0 FILLING GENERALLY 12.1 End tipping of fill shall not be permitted except in special circumstances and then only with the approval of the Engineer. Such approval shall not exempt the Contractor from compacting the end-tipped material to the requirements as specified in Clause 15. 12.2 When the state of the weather is such that in the opinion of the Engineer, it would adversely affect the placing of specially compacted fill, all such shall be stopped. 12.3 All filling material, whether placed and/or compacted or awaiting placing and/or compaction which, in the opinion of the Engineer, does not comply with the Specification, or has been damaged by weather or in any other way, shall be removed and replaced at the Contractor's expense. 12.4 Requirements under Clause 4 shall also be observed. 13.0 PLACING FILL 13.1 Fill shall be placed in even horizontal layers over the full width laid in thickness appropriate to the compaction plant used and compacted to satisfy the requirement as specified in Clause 15. At all times the embankments shall be maintained with a sufficient camber and a surface sufficiently even to enable the surface water to drain readily from them. 13.2 If the material deposited as fill subsequently reaches a condition such that it cannot be compacted in accordance with the requirements of the Contract, the Contractor shall at his own expense either: 13.2.1 Make good by removing the material off the fill either to tip or elsewhere until it is in a suitable physical condition for re-use, and replacing it with suitable materials; or 13.2.2 Make good the material by mechanical or chemical means to improve its stability; or 13.2.3 Cease work on the material until its physical condition is again such that it can be compacted as described in the Contract. 13.3. Rock material shall be broken down to dimensions not exceeding the compacted thickness of the layer in which it is placed. Rock material shall be well distributed in layers extending the full width of the fill, and sufficient fine material shall be placed around the larger material as it is deposited to fill the voids and produced a dense compact fill. Where insufficient fine material is present to fill the voids, additional fine material shall be obtained from other sources at Contractor's expense 8 EARTHWORKS Page 6 14.0 INSITU GROUND COMPACTION 14.1 Following ground preparation, the whole area shall be thoroughly compacted using a vibrating roller of approximately 5000 kg dead weight, e.g. Dynapac CA25 or Ingersoll- Rand DA30 roller as specified herein. Where small deep areas have to be compacted following local excavation of unsuitable material, the filling shall be placed in layers not exceeding 200mm loose and compaction may be carried out using approved vibratory tampers. The same degree of compaction as specified herein shall be achieved. 15.0 COMPACTION OF FILL 15.1 All materials shall be compacted in layers as soon as practicable after deposition. The thickness of each layer shall be compatible with the compaction plant used and shall be agreed with the Engineer. Earthmoving plant shall not be accepted as compaction equipment under this Clause. 15.2 Each class of material to be compacted shall be tested, prior to compaction, by approved agencies, in accordance with BS 1377 to determine its maximum dry density and optimum moisture content for compaction. 15.3 The moisture content of the insitu material during compaction shall be maintained as close to the optimum moisture content as possible. If necessary, this shall be adjusted by wetting or drying on site to enable the required insitu field densities of the fill material to be obtained consistently. 15.4 As an alternative to compacting equipment specified under Clause 14.1, Table 1.2 may be used as a guide for the Contractor in establishing compaction arrangement, however, site trials shall be carried out to ensure that the density requirement is achieved. 16.0 DEFINITIONS AND REQUIREMENTS ASSOCIATED WITH TABLE 1.2 16.1 The depth of compacted layer is the height by which an embankment is raised by each successive compacted layer. 16.2 For items marked * the rollers shall be towed by track laying tractors. Self propelled rollers are unsuitable. 16.3 Where combinations of different types of categories of plant are used, the compaction requirements shall be: 16.3.1 The depth of layer shall be that for the type of plant requiring the least depth of layer; and 16.3.2 The number of passes shall be that for the type of plant requiring the greatest number of passes. 16.4 However, where the Contractor uses a lighter type of plant to provide some preliminary compaction only to assist the use of heavier plant, this shall be disregarded in assessing the above requirements. 17.0 TESTING 17.1 Following the compaction process, insitu field density tests shall be carried out in accordance with BS 1377 Test No. 15(A) (Sand Replacement Method) or Test No. 15 (F) (Water Displacement Method). Each layer shall be tested and approved by the 9 EARTHWORKS Page 7 Engineer prior to the placing of the next layer where filling is required for construction of roads or non-suspended ground slabs. 17.2 Field density tests shall form the basis for acceptance of the compaction. These tests shall be carried out at the surface and at depths 1.0m and 3.0m below the surface. Each layer of fill shall be well compacted and have obtained the required density before subsequent layer can be laid. Field density tests procedure shall be approved by the Engineer. Density and moisture control tests shall be undertaken by the Contractor as and wherever directed by the Engineer. 17.3 As a measure of quality control the Contractor shall undertake field density tests at 10m centres as a minimum requirement around the areas of non-suspended ground slabs and at 10m centres along all roads. 17.4 All tests shall be reported in a format acceptable to the Engineer and shall be submitted for his approval. Daily records of field tests shall be kept available at the site for the Engineer's inspection. All sampling and testing shall be undertaken by a laboratory to be approved by the Engineer. The Contractor shall propose the names of at least 3 laboratories for approval and shall allow for all costs to comply with this specification and tests. 18.0 ACCEPTANCE CRITERIA 18.1 The following insitu field densities of compacted materials given as percentages of the maximum dry density derived from BS 1377 Test No.12 (2.5 rammer) or No. 13 (4.5 kg rammer), shall be obtained: 18.1.1 Within 500mm of formation level (subgrade or foundation) - 90% (maximum dry density using Test No. 13) 18.1.2 From 500mm to 1500mm below formation level - 90% (maximum dry density using Test No. 12) 18.1.3 More than 1500mm below formation level - 90% (maximum dry density using Test No. 12) 18.2 The Contractor may choose to establish by site trials the relationship among the insitu material for compaction, compaction plant used, thickness of each layer, and compacting effort in terms of number of passes. If so established and agreed by the Engineer, the Contractor shall follow the same compaction. However, the Engineer may at any time carry out insitu field density tests to determine whether the degree of compaction has satisfied the requirement in Clause 15. 18.3 The agreed compaction arrangement as mentioned in Clause 15 shall be adjusted when the compaction is found inadequate. 19.0 SETTLEMENT 19.1 The Contractor shall be responsible for making good to the satisfaction of the Engineer all settlement in filling and in backfilling which may occur up to the end of the Defects Liability Period. 20.0 SURPLUS EARTH 20.1 Surplus excavated materials after filling shall be removed, deposited, spread and levelled where directed within the confines of the Site. 10 [...]... and unloading Remarks 0 60 minutes 60 minutes 60 minutes 25% 50% 75% 1 cycle loading 6 hours 100% st Maintain Load st 10 minutes 10 minutes 10 minutes 60 minutes 75% 50% 25% 0% 1 cycle unloading 0 10 minutes 10 minutes 25% 75% 2nd cycle loading 6 hours 100% Maintain Load 60 minutes 125% 6 hours 150% Maintain Load nd 10 minutes 10 minutes 10 minutes 10 minutes 60 minutes 125% 100% 75% 25% 0% 2 cycle... minutes Remarks Maintain Load nd 200% 150% 100% 50% 0% 2 cycle unloading Minimum Holding Time % Load During Loading and unloading Remarks 0 60 minutes 60 minutes 60 minutes 25% 50% 75% 1st cycle loading 6 hours 100% Table C – Working Load Test Maintain Load st 10 minutes 10 minutes 10 minutes 60 minutes 75% 50% 25% 0% 1 cycle unloading 0 10 minutes 50% 2nd cycle loading 6 hours 100% Maintain Load 60... Agreement 16.0 CUT-OFF LEVEL AND STRIPPING PILES Piles shall be cut-off and strip to the levels as indicated on the drawings This work shall be carried out later during the main contract The Contractor shall liaise and co-ordinate with the main contractor to ensure that the works are carried out expeditiously The method of cutting the pile heads shall be accepted by the Engineer Care shall be taken to avoid... necessary approvals and pay all costs and expenses in this respect 22.4 The drains shall be sufficiently large so that no mud or water will spill onto the roads or pavements The Contractor shall also keep the main Authorities drains in the immediate and surrounding areas free from silting up owing to the effluent from the Site If the water is muddy, it will be necessary to place strutted and supported boarding... purposes of control 22.5.5 Where auxiliary sand drains are installed, such shall be considered an integral part of the system 22.5.6 The system shall provide for sufficient valves in leaders and pipes to maintain control over separate sections of the system 22.5.7 The contract sum shall be deemed to include for the above provisions, if deemed necessary by the Contractor 23.0 PLANKING AND STRUTTING 23.1... Contractor shall be wholly responsible for the stability of the piling and shall take every precaution to prevent deflection or movement of jacked piles and shall provide any temporary works necessary to maintain all piling in its proper position until permanently secured in the works 2.0 SOIL INVESTIGATION The results of soil bores carried out at the site are included in the tender document However, the... the proposed building and would be solely responsible for such consequences DEFECTIVE WORK 4.1 5.0 Defective work shall be all work which, in the opinion of the Engineer, does not fully comply with this specification or the drawings The Contractor shall make good or carry out such additional works at his own expense as may be necessary to make good all defective work to the Engineer's satisfaction TYPE... any pile, it shall be replaced entirely at the expense of the Contractor Page 1 of 7 27 8.0 EQUIPMENT AND PLANT The Contractor is to provide all frames, equipment, lifting and jacking devices, including maintenance and supply of fuel, with other plant, and labour necessary for the jacking of piles Before the commencement of piling, the Contractor is to submit to the Engineer full details of his working... and jacking the longest and heaviest pile expected The Contractor shall establish all lines, levels and be responsible for the correct positions of all piles Setting out shall be carried out from the main grid lines of the proposed structure Immediately before installation of the pile, the pile position shall be marked with suitable identifiable pins or markers 9.0 JACKING OF PILES The pile shall be... Unsuitable Unsuitable Unsuitable Vibratory Compactor Vibro-Tamper Power Rammer * See Clause 16.2 Page 8 12 EARTHWORKS 21.0 EXISTING SERVICES 21.1 21.2 22.0 The Contractor shall notify the Engineer of any mains, pipes or conduits met with during the excavation and where any excavation is carried out adjacent to or under any existing cable, and the like, the Contractor shall prevent damage by subsidence, . such as covering all surfaces with polythene, shall be provided and maintained. 4.3 The Contractor shall provide and maintain all necessary temporary access roads and shall divert and reinstate. shall be left with no area that can retain water. If necessary, the Contractor shall provide and maintain temporary and approved surface or subsurface drainage system to ensure minimum delay in. CLASSIFICATION OF EARTHWORKS 3.1 The following definitions of earthworks materials shall apply to this Specification: 3.1.1 'Top soil' shall mean the top layer of soil that can support vegetation.