Môc lôc VRAMP – CONTRACT PACKAGE RAI/CP 1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0 38B STRUCTURES / BRIDGES CONSTRUCTION METHOD STATEMENT FOR BORED PILES TABLE OF CONTENTS CHAPTER I MAT[.]
Trang 1VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B
STRUCTURES / BRIDGES
Trang 2VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B
CONSTRUCTION METHOD STATEMENT FOR
BORED PILES
TABLE OF CONTENTS
CHAPTER I : MATERIALS FOR PILING
I CONCRETE
II CASING
III REBAR WORKS
IV BENTONITE
CHAPTER II: CONSTRUCTION OF BORED PILES
I PREPARATION WORKS
II CONSTRUCTION SITE PREPARATION
III MIXING OF BENTONITE
IV DRILLING HOLE
V CLEANING OF BORED HOLE
VI INSERTING OF STEEL CAGE AND CONCRETE PLACING
VII EXTRACTION OF CASING
VIII FINAL PILE TOE LEVEL
IX POSITIONAL TOLERANCE
X REPORT
XI REPORT FOR QUALITY CONTROL OF BORED PILE
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Reference standards:
- 22 TCN 257 : 2000 Cast in place pile, Specification for construction acceptance
- TCXD 88 : 1982 Pile, Field Testing Method
- 22 TCN 266 : 2000 Bridge and Culvert, Technical requirement for construction
- 22 TCN 272 – 05 Bridge Design Standard
- Orther related ASTM and AASHTO
CHAPTER I : MATERIALS FOR PILING
I CONCRETE
1 General requirement:
The materials for production of concrete to ensure the technical requirements
defined under Specification section 06100 “ Concrete and concrete structures ”.
During the storage, transportation, materials must be stored to avoid contamination or mixed grain sizes and types When encountering such cases should immediately remedy to ensure the stability of quality
2 Materal:
a. Cement
The cement shall be Portland cement Type I, complying to all respects with TCVN 4033:1995 or some other cement that approved by Engineer Cement approved
by Engineer shall be uses for entire concrete of Project, except otherwise instructions in writing
The source of supply of cement shall be subject to the Engineer’s approval and the Contractor shall at all times furnish the manufacture’s test certificates and proof that the specifications have been complied with, together with a note of the date of manufacture, certified by an independent agency in the country of origin
Cement shall be delivered to the Site in sealed bags or water-tight barrels bearing the manufacturer’s name, cement type and the date of manufacture The bagged cement shall be stored in piles not more than eight bags high Storage areas shall be perfectly dry waterproof sheds or other such temporary buildings approved by the Engineer The storage capacity shall correspond to the amount of concrete required for the largest units to be cast These buildings shall be used exclusively for the storage of cement and shall be erected with the floors raised well above the ground at places on or near the Site of the Works; and at the completion of the Works the buildings shall remain the property of the
Trang 4VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B Contractor and shall be dismantled and removed, the foundations broken up and the site restored to its original condition by the Contractor
A free passage of at least one meter shall be left between the cement and the side walls of the sheds Each consignment of cement shall be stored apart form earlier consignments and consignments shall be used in the order in which they are delivered
The Contractor shall provide weighing machines which shall be kept permanently
in each shed for checking the weight of the bags or barrels of cement
Cement delivered by bulk carriers shall be stored in silos made for cement storage The cement shall be handled in bulk by use of air-veyors, auger-screw conveyors, enclosed bucket or enclosed belt conveyors All operations for handling of bulk cement shall be by methods that prevent contamination of the cement.The cement storage silos shall be provided with interior moisture control devices that keep the cement dry and prevent premature hydration in the silos.The silos shall be provided with access ladders and entry ways so that samples can be extracted from various levels of each silo for testing purposes
b Water for Concrete Mixing and Curing
The Contractor’s proposed water source shall be submitted to the Engineer for his approval together with test results confirming that water from the source complies with this specification
Water for concrete mixes, curing concrete and other products containing cement shall be clean water free from oil, salt, acid, sugar, vegetable or any other substance injurious to the concrete unless otherwise authorized in by the Engineer
The contractor will do frequency test of water at the location and time as required by the Engineer
c Aggregate
Aggregate cement is not contained harmful alkaline reagents in cement with sufficient quantity to cause the excessive expansion of concrete The Contractor must take the tests to proved that aggregate is free from such harmful substances The certificate includes of the equivalent character of concrete in the same condition that is submitted Tests must be conducted in the lab that is met the Specifications
The aggregate includes of the particles tough, hard, durable and no other contamination The Contractor is responsible for setting up this aggregate to meet the specification The Contractor shall advise the Engineer of the sources
of aggregates to be used to permit samples to be taken in the presence of a representative of the Engineer and the Contractor to test before being brought to the Site
Trang 5VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B Aggregate is stored into the stack to free drainage and separated and prevent contamination Aggregate is mobilized to site is available and separated to avoid their mixing The aggregate marked types of aggregates present in the heap The Contractor shall gather aggregate at the site in sufficient quantities to ensure that there is no interruption in the process of pouring concrete in any time Contractor will set up the yards for the main material near the mixing station Material shall be inspected and approved by Engineer before commencement of work
Both fine and coarse aggreates shall be tested in accordance with the following standarts:
TCVN 7572-2:06 Sieve Analysis
TCVN 7572:06 Organic Impurities
TCVN 141 - 86 Soundness
Fine Aggregates
+ Fine aggregate for Portland cement concrete shall consist of natural sand or other inert materials with similar characteristics, having hard, strong, durable particles Fine aggregate shall be clean and free from extraneous materials, clay balls, organic matter or other detrimental material in accordance with AASHTO M6 The maximum combined quantity of soluble chlorides and sulphates in the fine aggregate shall not exceed 1000 ppm fine aggregate
+ Fine aggregate shall be reasonably graded and shall meet the grading requirements mentioned in Table 1
+ The fine aggregate shall be of such uniformity that the fineness modulus as defined in TCVN 7572-2:2006 shall not vary more than 0.20 either way from the fineness modulus of the representative samples used in the mix designs
Table No 1- Grading Requirements of Fine Aggregate
Sieve Size (mm)
Percent Passing by weight
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Sieve Size (mm)
Percent Passing by weight
Coarse Aggregates
+ Coarse aggregate shall be crushed aggregate and shall be homogeneous, clean, and free from extraneous materials, clay lumps, organic matter, and other detrimental materials Coarse aggregate shall meet the requirements of TCVN 7570:2006
+ The percentage of wear of the aggregate shall not be greater than 50
as determined by TCVN 7572-12:2006
+ The quarry from which the coarse aggregate is to be obtained shall be approved by the Engineer before material is delivered to the Site of the Works
+ Coarse aggregate shall meet the requirements of TCVN 7570:2006
+ The coarse aggregates shall be reasonably graded and shall meet the grading requirements in Table 2
Table No 2 Grading Requirements of Coarse Aggregates
Sieve Size (mm)
Percent Passing by Weight Concrete
Class A, B, C and D
Concrete Class E and F
Concrete Class G and P
d Admixtures
To avoid cold joints the Contractor shall provide sufficiently large capacity in his concrete producing plant and concrete transporting arrangements and use an appropriate retarder when deemed necessary by the Engineer The retarder shall
be of a type approved by the Engineer and shall comply with the requirements of TCXDVN 325:2004
Trang 7VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B Retarders shall not be used together with other admixtures in the same mix unless approved by the Engineer
Preliminary tests of cylinder strength and any other tests shall be carried out for all concrete with admixtures When the Engineer approves changing the brand or type of cement, the Contractor will be required to carry out further tests and establish a relative mix design
Water reducing and water reducing-retarding admixtures, in accordance with TCXDVN 325:2004 and plasticizing and plasticizing and retarding admixtures in accordance with 22 tcn 202-1998 may be used with written permission of the Engineer in accordance with mix designs and slump requirements as approved
by the Engineer
Calcium chloride or admixtures containing calcium chloride will not be permitted
II CASING
1 Temporary casings
Temporary casing was made in workshops with 10mm thickness The length of casing shall be based on the borehole geology and construction methods drawings of bored piles
Temporary casing is used for bored piles of Trang Thua bridge, Cong Neo bridge The length of steel casing is in accordance with 22TCN257-2000
2 Permanent Casings
Permanent casings shall be used where specified on the Drawings or as instructed by the Project Manager and shall conform to in accordance with 22 TCN 257 -2000 or ASTM A36 or equivalent
The minimum thickness of the permanent steel casing shall be as shown on the drawings
The steel casing shall be furnished in appropriate lengths
The casing shall be handled and stored in a manner that shall prevent buckling and other deformation as well as accumulation of dirt, oil and paint When placed in the work it shall be free from dirt, oil, grease, paint, mill scale and loose or thick rust
III REBAR WORKS
All reinforcement steel shall comply with the requirements of Specification Section 06400“Reinforcing steel”
Reference standards:
- TCVN 1651 : 2008 - Reinforced concrete
- TCVN 570 : 93 Hot rolled steel for armouring reinforced concrete constructions
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- TCVN 6284-1 : 1997 Pre-stressing Steel
- ASTM - A615 Deformed and Plain Billet-Steel Bars for Concrete Reinforcement
1 General requirements
Rebar used in reinforced concrete structures must be ensured the design requirements
Rebar is fabricated at site but to ensure appropriate level of mechanical quantities corresponding to the processing of steel
Do not use the same steel works the same shape, size geometry, but different physical properties
- Rebar before fabrication and placing must ensure that:
The surface is clean, no sticky dirt, grease, no rust flakes and layers of iron
The steel bars were crushed, reduced cross section due to cleaning or other reasons shall not exceed the permitted limit of 2% in diameter If this limit is exceeded such steel are used in actual sectional area remaining
Rebar must be bending, pulling and straightening
2 Cut and bend rebar
The processing of Rebar is in compliance with project standards
Cut and bend rebar shall be conducted only by mechanical methods
Bar reinforcement shall be cut and bent to the shapes shown on the Drawings Fabrication tolerance shall be in accordance with ACI 315 All bars shall be bent cold, unless otherwise permitted Bars partially embedded in concrete shall not
be fied bent except as shown on the Drawings or specifically permitted
3 Production of steel cage
Rebar is fabricated in right size and dimensions as shown in the drawings and are installed properly and the center hole in the approval of the Engineer
It must pay a special attention to the implementation of the "The positioning bar
of steel cage" have outstanding tolerance not exceeding 10 mm in all directions, will not be allowed to pour concrete until approved by Engineer
All pads or the distance must be anchored with rebar certainly to ensure firmly with steel cage
Make sure the length and height of welding as required
Steel piles are processed into individual cages with a total length in connection equal to the length resuming steel cage design
IV.BENTONITE
Trang 9VRAMP – CONTRACT PACKAGE:RAI/CP-1 – TRANG THUA AND CONG NEO BRIDGE ON NATIONAL HIGHWAY N0.38B Bentonite, immediately prior to mixing, shall be in accordance with specification DFCP4 of the Oil Companies Materials Association (Drilling fluid materials – bentonite), or the American Petroleum institute Standard 13A
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Chapter II: CONSTRUCTION OF BORED PILES
I Preparation works
Construction equipment includes :
Drilling equipment: is a self-propelled crane for craning casing, equipment and erecting the drilling machine
Drilling equipment includes of grab buckets as mechanical or hydraulic dredging buckets
Mixing equipment, tanks and bentonite pumps
Vibrating hammer with hydraulic power 170KW is enough capacity for lowing the casing into the hard ground
Cleaning equipment: betonite pumps, compressors 10m3/minutes
Other construction equipment such as tremie pipes, concrete vehicles, mix truct, welding equipment, etc
List of equipment
Item of work Trademark Description / Number From Remark
Drilling
equipment with
Kelly crane
Drilling depth 80m, diameter Max 2.0m
ny
Sand separation
system for
betonite fuid
04
Test set of
a Testing set of