110509 WSA 062 MS for box culvert construction EN attachment 1

Biện pháp thi công cống hộp dự án cao tốc Long Thành Dầu Giây MS for box culvert construction at Long Thanh Dau Giay Express Biện pháp thi công cống hộp dự án cao tốc Long Thành Dầu Giây MS for box culvert construction at Long Thanh Dau Giay Express Biện pháp thi công cống hộp dự án cao tốc Long Thành Dầu Giây MS for box culvert construction at Long Thanh Dau Giay Express Biện pháp thi công cống hộp dự án cao tốc Long Thành Dầu Giây MS for box culvert construction at Long Thanh Dau Giay Express

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9.3 Box Culverts in Embankment Fill – Soft Foundation 10

9.4 Box Culverts in Embankment Fill – Firm Foundation 10

9.5 Box Culverts in Embankment Cut – Rock Foundation 10

9.6 Box Culverts in Embankment Cut – Soft Foundation 11

9.7 Final Stage 11

10 Quality Control and Quality Assurance 11

11 Risks 12

12 Safety and Environmental Measure 13

General 13

Life Saving Appliances 14

Environmental 14

This method statement provides the details of the materials, the equipment, the procedure and relevant documents related to the construction of Box Culverts and related activities, including the quality control verifications, the measurement verifications, and also the safety precautions to be implemented for this

Scope of this method statement applies to Construction of Box Culverts at the locations

shown in the contract drawings Detailed design will be prepared for each location according to the invert level approved by the Engineer shall be adopted for construction purpose The working drawing accompanied with the bar schedule, lapping arrangement and will be submitted and approval will be taken prior to commencement of site work For all temporary diversion during construction, the contractor shall submit a formal application with the traffic diversion scheme to the appropriate local for notice and carried out accompanied with the diversion of road pavement shall be similar to the existing road pavement and throughout the construction period the diverted road shall be maintained without potholes

The placing of precast Box culvert are the option it will be implement at site with Engineer Consent

• Preparation

• Setting out

• Construction of Bedding Sand and Concrete

• Placing of Precast Box Culvert or In Situ casting as per the Dimensions in

Drawings

• Finished the work to continuation

3. Reference Standards

The following Standards in their latest edition shall be particularly applied to the works covered by this Method Statement

♦AASHTO M259 Precast Reinforced Concrete Box Sections for Culverts,

Storm Drains, and Sewers

♦ AASHTO T11 Materials Finer than 75-µm (No.200) Sieve in Mineral

Aggregates by Washing

♦ AASHTO T27 Sieve Analysis of Fine and Coarse Aggregates

♦ AASHTO T89 Determining the Liquid Limit of Soils

♦ AASHTO T90 Determining the Plastic Limit and Plasticity Index of Soils

♦ ASTM D543 Evaluating the Resistance of Plastics to Chemical Reagents

♦ ASTM D570 Water Absorption of Plastics

♦ ASTM D638 Tensile Properties of Plastics

♦ ASTM D2240 Rubber Property—Durometer Hardness

4. Quantity

Estimated quantity ( bidding quantity ) is as follows But they are only for reference The design quantity will be made from approved working drawings The actual construction quantity will be shown on As-built Drawing

No Station Description

Length ( m )

Skew Angle (%)

Element

s

of Pi pe Bedding

Foundation

No of El e m en ts

Length

of ea

ch El e m en ts

t=0.1 gravel

t=0.3 Conc C20

t=0.3 Conc C20

t=0.1 gravel

t=0.3 Conc C20

t=0.1 gravel

t=0.3 Conc C20

5 27+842 3x(2.0mx2.0m) 48.21 101 48 1m gravelt=0.1

t=0.3 Conc C20

6 29+820 2x(1.5mx1.5m) 41.44 90 44 1m gravelt=0.1

t=0.3 Conc C20

7 30+120 4x(2.0mx2.

t=0.1 gravel

t=0.3 Conc C20

8 31+040 1.5mx1.5m 31.34 90 31 1m t=0.1

gravel

t=0.3 Conc C20

t=0.3 Conc C20

10 32+980 4x(2.0mx2.5m) 31.34 90 31 1m gravelt=0.1

t=0.3 Conc C20

gravel

t=0.3 Conc C20

t=0.3 Conc C20

gravel

t=0.3 Conc C20

gravel

t=0.3 Conc C20 This shall be carried out in accordance with 07950 in Part 2 section 6 as specified in the Employer’s requirements.

The site organization chart is shown as below

Project Director

Construction Manager

QA/QC Manager / Site Manager

6. Equipment and Resources

6.1 Equipments

7 Rock Drilling Machine (If trench involves rock excavation){If Required} 01

Note: above stated quantity of equipments could be changed if any required and necessary

6.2 Materials

Sub-contractor Project Manager Site Manager

Site Engineer Foremen Operator Worker

No Category Quantity

Note: Samples of materials shall be submitted separately.

After obtaining the approval for Construction drawings, base on the contract shall be carry out the scope of work

8. Site Facilities

• Available access roads will be used for the necessary machinery and Equipment to

delivering

• Provide access (Service/Temporary roads) as accepted by engineer for public beyond ROW

Flow Chart

Step 1 – Preparation and Setting out

Step 2 – Construction of Bedding

Step 3 – Placing of Precast Box Culvert

or Cast Insitu at Site as per Engineer’s

Consent

9.1 Preparation

The Contractor will maintain an adequate number of trained and experienced supervisors and foremen at the site to supervise and control work Adequate number

of labours will be maintained for all construction activity including skilled masons, skilled carpenters and skilled person to operate the vibrators.' All construction other than concrete will be confirmed to the requirements prescribed in other sections of the specification for the several items of work entering into complete structure

Prior to commencement of the work, the Engineer will be requested to participate for

a joint site visit & to confirm the location of the Drainage Box Culverts as given on the drawing (Plan & Profile) Where possible the Engineer will confirm the foundation applicable at each particular location as specified in drawings The length/ width/section type of the Box Culverts will be requested in embankment filling or cutting for purpose of Box Culverts constructions The preparation of construction drawings will then proceed in consideration of the ground conditions and above data to ensure that the steps of the procedure are fully complied with during the activities as per section 7950 clause 3.1 of technical specification such as setting out, excavation, embankment filling, formwork, reinforcement, concreting, backfilling and other activities etc certain inspections and verifications will be carried out as outlined in the attached Inspection & Test Plan Measurements relative

to construction Drainage Box Culverts will be taken off from the approved drawings Variations if will be recorded during the course of the works, the relevant drawings will be revised accordingly and obtain approval from the Engineer

9.2 Setting out

• Setting out will be carried out with the help of the survey data provided in the drawings

• If required, the existing stream flow will be diverted so that the new construction works will not be affected by the water flow

• Survey Records for joint measurements all Excavation works

• Survey Records for joint measurements all filling works

Step 4 – Backfilling

• Site measurements for pipe length

Horizontal and Vertical Control

Centerline points (a) – (PoC), (PoT) ,(PoT) and

(PoC ) including references thereto

Cross-Section points, slope stakes, and slope

stake reference (b)

Culverts, ditches, and minor drainage structures ± 10 mm ± 10 mm

Note : (a): Center line points are point of curve ( PoC), point of Tangent (PoT) and point on curve ( PoC)

(b): Take the cross sections normal to centerline within ± 1 degree (0.02 rad)

• Acceptance Criteria

The finished dimensions of box culverts shall be as follows;

Dimension Tolerances

Box Culvert Wing wall Apron Approach Slab Center Position

±5 mm

Top Level

±5 mm

Invert Level

±5 mm

Dimension

Inner & Outer

10 to +20 mm*

Verticality

1 in 300

Top Grade

Irregularities

±2.5 mm

Bedding

• Sand bedding shall be arrange the detail given in drawings as 100 mm thick, Material

as specified in 2.2 of Section 07950 Sand PI ,LL and Gradation as specified

• Lean Concrete Bedding

• C-20 lean concrete bedding as specified in drawings and Concrete as per section

07100 in technical specification

• Cut off Plates (water Stop)

• As per drawings and specified in 2.2.2 in technical specification

(A) Installation of Box Culvert

Contractor used the pre cast box culvert from approved sources and place by segments (pre cast boxes) as specified in drawing as consent given by the Engineer

It will be place in the required ground stipulated after the given below treatment for foundation Used Mobile crains for this matter and will evaluate the relevant dimension and detail for measurements

(B) Cast in Place of Box Culvert

Formwork, false work and Centering

Formwork will be included temporary and permanent moulds for forming concrete and tight and rigid enough to maintain the concrete in position during placing, compaction, setting and hardening The design calculation with typical sketches showing the thickness of molding plates, details and intervals of struts and side supports shall be submitted for verifications

Engineer's approval will be taken before placing concrete for all formwork, false work and centering For detailed information regarding inspection requirement of formwork, all the approval of the material quality shall be obtained from the Engineer reasonably before commencement of work

Reinforcement

All reinforcement will be placed, supported and secured in accordance with the requirement of section 07500 reinforcement and approval from the Engineer will be taken before beginning of concrete operation An experienced steel fixer will be present while all concrete is placed to ensure that no reinforcement becomes displaced Before placing the bars shall be cleaned with wire brushes to remove rust

Placing Concrete

All concrete will be placed within the times specified (Concrete Structures) in such

a manner as to avoid segregation and the displacement of reinforcement bars Ready mixed concrete and concrete truck mixer will be used ' Chute /skip bucket 1 , Concrete pump car will be used when concrete to be placed with vertical distance of more .Concrete will be thoroughly compacted by concrete vibrator during the operation of placing Adequate working condition concrete vibrators will be available prior to the concrete pour with one or two reserve vibrators Before initiate placing concrete PVC ducts will be placed for lighting and other services as stated in drawings

determine the compressive strength of the concrete Slump test shall be carried out each mixer truck before placing the concrete An inspection sheet will be forwarded

to the Engineer to receive the Engineer's certification for placing concrete in accordance with the Inspection Test Plan for Concreting Works Concrete temperature will be maintained by contractor as specified

Curing and Removal of formwork

All concrete surfaces will be kept wet for minimum 7 days after placing concrete by water or by the use of wet burlap The formwork will be removed according subject

to mandatory Engineer's approval

9.3 Box Culverts in Embankment fill - Soft Foundation

The Engineer will be required to issue his instructions for the removal of the unsuitable material to a specified width, length and down to a specified depth, or provide other instructions for ground treatment at the option of the Engineer No any ground treatment in Our BOQ for this project

Embankment filling & compaction will be carried out in layers as stated in the

Method Statement for Earth Work Compaction testing will be done as specified in

the technical specifications

An inspection sheet will be forwarded to the Engineer to receive the engineer's certification for completion of the work instructed by the Engineer

Then the procedure mentioned above will be adopted to perform the task as Method

1 and Method 2

9.4 Box Culverts in Embankment cut - Firm Foundation (Soil)

Excavate the trench with the help of excavator down to the required level and additional excavation of 500mm from out side of the footing Excavated material deposit in storage piles for the further use of backfilling Side slope will be trimmed and benched

Then the procedure mentioned above will be adopted to perform the task as Method

1 and Method 2

9.5 Box Culverts in Embankment Cut - Rock Foundation

Excavate the trench by blasting in accordance with the blasting pattern approved by the Engineer This additional excavation will be backfilled with approval material Rock excavation will be performed as mentioned in the Method Statement for Earthwork and the Construction Procedure for Rock Blasting works Dimension of the trench varies in accordance with the drawings

Then the procedure mentioned above will be adopted to perform the task as Method

1 and Method 2

9.6 Box Culverts in Embankment Cut - Soft Foundation.

If the ground material observes soft, spongy or unstable, seek for Engineers approval

to remove and replace the soil The excavated area will be backfilled with granular material and compacted up to the original ground level as specified Excavate the trench with the help of Excavator down to the required level Additional excavation will be done according to foundation soil condition and backfill up design level Where necessary, the slopes of the trench will be shored to ensure cutting angle Slope will be trimmed and benched to protect collapsing excess soil and steel timber piles arranged for shoring work In the case of excess water along the trench, dewatering will be arranged with adequate water pump Dimension of the trench varies in accordance with the relevant drawings

Pile will be driven as stated in the Method Statement for Concrete Piling according

to the ground condition and Engineer's instructions

Then the procedure mentioned above will be adopted to perform the task as Method

1 and Method 2

9.1 Final Stage

Embankment filling & compaction will be carried out in layers up to required design

as level shown in contractor's detailed Drainage Box Culverts vary in each location Density testing for the Embankment works will be done as specified in the technical specifications

Backfilling will be commenced after the Engineer's consent Suitable classified fill material will be used as backfill material Backfill layers will be compacted using plate compactor and/or rammer Compaction testing will be done as specified in the technical specifications

certification for completion of backfilling and compaction for each Drainage Box Culverts in prior to commence the adjacent Embankment filling

Material

Materials shall be submitted for Engineer’s approval prior to delivery onsite ( sample, supplier, material sources…etc ) The major materials used for the construction of Box culverts include, but are not limited to the following

♦ Reinforced Concrete box (Pre-Cast) from approved manufacturer as accepted by the Engineer.

♦ Cement mortar as stated and from approved Cement

♦ Structural Backfill Materials as approved by Engineer

♦ Bedding Materials as approved by Engineer as indicated above as Sand and lean concrete bed C-20 concrete mix.

♦ Sand Material PI and LL and Gradation tests will be carryout prior to use for permanent work as specified in specification

♦ Other relevant material for construction should approved by Engineer as required prior to use for any work and also test as specified in Specification.

Quality Assurance

Quality Assurance is carried out according to the Project Quality Plan For the purpose of Quality Assurance, we are planning to use

♦ Inspection & Test Plan Sheet

♦ Check List – Daywork Record Sheet

♦ Check List – REQUEST FOR INSPECTION CHECK FORM (RICF)

♦ Check List – Measurement Summary

♦ Check List - Confirmation of Verbal Instruction (CVI) Copy of the each and every Inspection and Test Plan and Check List is filed and keep

in the Site Office

• Human damages when Pre-cast Box Culvert laying:

Solution: