Biện pháp thi công đắp K95 Đây là biện pháp mô tả quá trình thi công thử nền đắp K95, đã được Tư vấn giám sát xem xét và chấp thuận. Biện pháp diễn giải chi tiết các bước thi công tại hiện trường phục vụ công tác thi công cho nhà thầu. Biện pháp cũng tuân thủ đầy đủ theo các tiêu chuẩn của dự án và các tiêu chuẩn hiện hành của Việt Nam cũng như quốc tế.
Trang 1PACKAGE No.6: CONSTRUCTION OF KM0+000 TO KM KM15+15.630 SECTION
(INCLUDING SHOP DRAWING)
METHOD STATEMENT OF TRIAL COMPACTION OF EMBANKMENT CONSTRUCTION BELOW SUB-GRADE
K95 OF SECTION FROM KM0+00-KM4+501
Trang 2Lach Huyen Infrastructure Construction Project (Road and Bridge Portion) Contract Package No.6
1
METHOD STATEMENT OF TRIAL COMPACTION
OF EMBANKMENT CONSTRUCTION BELOW SUB-GRADE K95
OF SECTION FROM KM0+000 TO KM4+501 TABLE OF CONTENT
1 GENERAL 2
2 TRIAL COMPACTION LOCATION AND DIMENSION 2
3 QUANTITIES 2
4 WORKING TIMES 2
5 SITE ORGANIZATION CHART 3
6 MATERIAL 3
7 EQUIPMENT AND MANPOWER 3
8 METHOD STATEMENT 5
8.1 P REPARATION 5
8.2 MATERIAL ELEVATION 5
8.3 CONTROL PLAN AND MOISTURE ADJUSTMENT 5
8.4 CONSTRUCTION PROCEDURE 6
9 QUALITY CONTROL PROCEDURE 8
10 SAFETY CONTROL 8
11 ENVIRONMENTAL CONTROL 9
APPENDIXES: Appendix 1 - Trial Compaction Location .10
Appendix 2 –Organization chart 11
Appendix 3 – Inspection sheet for trial compaction 12
Appendix 4 – Document of Equipment 13
Trang 32
1 General
This method statement describes the trial compaction for the embankment,
which will be approved by the Engineer in accordance with Technical
Specifications - Division 3: Earth works - Section 03400: Embankment construction and section 03900: Soft soil improvement measures
The object of this trial will be determined the optimum moisture content and the relationship between the number of passes of compacting equipment and density obtained for the embankment material under trial (K95 density); Affirm the quality control method; Determine the spread layer thickness before compaction and propose the thickness of each embankment layer (after compaction)
2 Trial Compaction Location and Dimension
The trial compaction area will be located in the main road at the station as attached Appendix 1 and may be adjacent location depending site condition and the contractor shall be submitted for the Engineer approved before carry out of the work The dimension of the trial compaction area is Width x Length = 10m x 50m and thickness of sand layers before compaction are 25cm, 30cm
For each kind of trial compaction layer h=25, 30 we shall be carried out for three layers to ensure the quality depending on actual construction site
3 Quantities
Trial compaction quantities shall be prepared as following table:
4 Working times
We shall work during daytime and 5days/week but when on the construction process
of construction requires time extension then we will carry out overtime work under the Engineer
The proposed working time for construction:
Trang 4Lach Huyen Infrastructure Construction Project (Road and Bridge Portion) Contract Package No.6
3
Time 8:00~12:00 1:00~5:00 Working shift per week 5days/week
Working shift per month 20~23days/month Working plan for overtimes works shall be submitted and approved by the Engineer
5 Construction schedule
Construction schedule shall be referred to “ Overall Project Execution Program” approved by Engineer ( Rfe.No STCJV/20140719-3) and the Employer and updated
in every weekly and monthly meeting
6 Site Organization Chart
Organization Chart is as the attached appendix 2
Select Team Phu Thinh Company to carrying out trial compaction
7 Material
- The material to be used for trial compaction work is sand for embankment
as proposed material that submitted to the Engineer;
Layer of 50 cm below Sub-grade
- A layer of 50 cm below subgrade (embankment) shall be in compliance with the requirements for each item according to Table No.1 below In case the material is sand, Liquid Limit (LL) ≤ 55% according to TCVN4197-95 (or AASHTO T89), Plasticity Index ≤ 27% according to TCVN4197-95 (or AASHTO T90)
- The minimum CBR of layers less than 100 cm below subgrade level shall be 8% according to 22TCN332-06 (or AASHTO T193:90)
- The minimum CBR of layers more than 100 cm below subgrade level shall be 6% according to 22TCN332-06 (or AASHTO T193:90)
TABLE 1 Classification of Materials Suitable for Embankment (AASHT M145)
Group Classification:
A-1
A-3
Sieve Analysis, Percent Passing:
Characteristics of fraction passing 0.425 (Sieve No 40):
Types of Significant
Constituent Materials
Stone fragments,
Trang 54
(*) A-2 can be used for embankment construction upon the Engineer’s consent based
on the actual conditions, laboratory test results, and testing on trial sections performed with the proposed material
8 Equipment and manpower
- The equipment used for the trial compaction work is shown in below table In case other type roller is be used for compaction work, another trial compaction test will
be carried out as necessary
No List of
equipment Capacity Type, Mode Quantity Remark
1 Bulldozer 110 ~140CV 1 each
2 Excavator 0.6~ 1.6m3 1 each
3 Static roller 8-16T As appendix 4 1 each
4 Vibrating roller 16~25 T As appendix 4 1 each
5 Water pump 36-80m3/h 1 each
6 Dump truck 7Ton 4 each
7 Dump truck 25Ton 3 each
8 Theodolite 1 each Survey
9 Level
equipment 1 each Survey
10 Lab testing
equipment
For Field density test LAS-XD250 1 set
Note: The site laboratory LAS-XD250 was submitted to the Engineer by letter LH/JV-ENG/165 July 29, 2014
The manpower will be involved for the trial compaction work, is shown in below table:
1 Foreman 1
2 Machinery Operator 3
3 Site engineer 2
4 Worker 5
5 Lab Staff 2
6 Survey team 1
Trang 6Lach Huyen Infrastructure Construction Project (Road and Bridge Portion) Contract Package No.6
5
9 Method statement
The construction procedure will be followed below steps and shall be instructed by the Engineer
9.1 Preparation
- The location of trial compaction work will be on area after site clearing and grubbing work finished Marking the trial compaction area at 4 corners by bamboo pile;
- Sand material should be approved by the Engineer, checking at material storage yard (gather sand at the area Km4+040-Km4+080) in accordance with mechanical characteristics of sand before transporting to the site;
- Calculating necessary sand quantity for trial compacted section based on the thickness of filling layer before compacted thickness 25, 30
9.2 Leveling Material
After Sand transported to the site & dumped at the required positions, the contractor will carry out leveling layer by layer according to the horizontal by bulldozer Using bulldozer to flatten material layer by layer with uniform thickness h=30, 25
9.3 Control plan and moisture adjustment
After spreading the sand out on the compaction area, the sand moisture will be checked, if the actual moisture less than 3% or higher 1% optimum moisture the work of spreading and compaction can be carried out In case of the actual moisture
> 3%, the sand will be spread and exposed to the sun to reduce the moisture to Wop (3%> Wop >1%), if the actual moisture less than 1% the work of supply more water
by water pump and tank truck is necessary
9.4 Work Execution steps
The contractor will carry out the trial construction of 25cm layer, if the density meets requirement, the contractor will apply for construction of 25cm layers in whole route
The construction procedure will be followed below steps:
- Use the bulldozer to level the area of trial compaction smoothly;
- Marking the trial compaction area at 4 corners by bamboo pile;
- Use bulldozer to level the sand smoothly Before compaction, the thickness of sand layer shall be 25 The trial compaction layers shall be compacted and shaped to a 4
% grade from the center to both sides for drainage of rainwater during construction;
- Compact from out site to in side
Trang 76
- Use static roller with 10-12T compact 3 times/1 point
- Use vibrating roller with 25T compact 5 times/ 1 point
- Check the density if it achieves K95, the contractor will stop for defining compaction factor
- If it does not achieve the required density, the contractor will use vibrating roller with 25T for compaction 2 more times After the contractor for will check the density, if it still doesn’t achieves K95, the contractor will keep compacting 2 more times up to the density K95 define compaction factor
The accepted compaction sequence shall be applied for embankment construction work
The chart form for trial compaction report:
Compacting equipment *
Density
Passing number
Density
Moisture
Trang 8Lach Huyen Infrastructure Construction Project (Road and Bridge Portion) Contract Package No.6
7
10 Quality control procedure
Checking quarry
NO Find other quarries
OK Transporting material to storage yard
Tacking and NO testing
sample
OK Transporting material to construction site
Surveying existing ground by surveyor
Spreading material
Checking NO thickness
OK Compaction
Field NO density test
OK Checking thickness
Test result report approved
Apply to construction
Trang 98
11 Safety control
- Prior to the commencement of works, training courses shall be held for all employees to master the construction procedures, specifications and project safety
- Specific duties and responsibilities shall be assigned to all positions in the construction activities Highest attention shall be paid during the process of the works Personal protective is supplied for all employees
- All employees shall have to obey the site manager’s instructions The operation of all equipment shall conform to the specific procedure for each type
- Any deficiencies found during the construction shall be immediately reported to the site manager for proper and prompt measures to be taken
“Safety Control Plan” shall be conforming to Approved Project Safety Control Plan (Reference to letter (Ref.No.SMTC20140519-2) dated 19th may, 2014) shall be part
of this method statement Prior and during the execution, basic safety precautions shall be implemented to work efficiently and to prevent any accident or casualty
12 Environmental control
“Environmental Control” shall be conforming to Approved Environmental Control and Protection Plan (Reference to letter (Ref.No STCJV/20140606-1) dated 6th June, 2014) shall be part of this method statement
If any other problems occurred in the site, applicable counter measures or prevention action shall be considered immediately and executed as soon as possible
To make the drainage ditch for collecting water into a batch basin for settlement before pump out Pump will be installed for dewatering in order to keep dry construction area
Water will be discharged to public irrigation system after settlement at a catch basin All the machine will be operated slowly at the area near resident to prevent from noise
Machine oil will be collected properly and be disposed to approved area
Trang 10Lach Huyen Infrastructure Construction Project (Road and Bridge Portion) Contract Package No.6
10
10
Appendix No.1 TRIAL COMPACTION LOCATION