Method Statement_of Deep Cement Mixing

1. Method Statement of D. C. M
7-Apr-11
Company
Date
Boubyan Seaport Project Phase 1
Deep Cement Mixing Method

2. Method Statement of D. C. M

5. Method Statement of D. C. M
3)Preparation
(1)GPS installation & Survey
- GPS(RTK Type)
- Total station
(2) Checking obstacle
- DCM works has to be started,after obstacle or poor sediment is removed by diver.
4)Method
(1) Checking DCM barge condition
①Maintenance of DCM barge.
②Checking condition of drilling equipment(Auger, Rod, Bit and etc ).
③Checking Working platform & Working Section on board.
(2) Checking MIXER PLANT
①Checking Mixer plant & Silo.
②Checking Subsidiary equipment(Generatir, Compressor, Pump and etc.) & Electric wiring condition.
③Based on specification, data of mixture ratio(W:C) input & checking condition of slurry transfer
and line installation.
(3) Barge for Bulk Transportation Setting
①Barge comes alongside the quay wall
②Silo for transportation loading on board

6. Method Statement of D. C. M
(4) Survey & Equipment setting
①The control point is selected by use of criterion surveying point and install referring point.
②The working point is selcted by G.P.S survey.
③After setting of the working point is completed, DCM barge would be fixed up by winch.
(5) Atter penetrated under water, drilling would to be carrird out by water.Design data of injection
volumes input on flowmeter then agitate cement paste for 2~3minutes.
①Using removal pump, slully is injected as average 130ℓ/min per pump 1GB
②There is dropped as average 2.0m/min, then rising 2.0m/min for soil improvement.

9. Method Statement of D. C. M
7)Quality Control Test
①Sampling
Sample for unconfined compressive strength test takes at workinr point using Sampling device.
After sampling device fixed on mixing blade, agitator is penetrated then pull out and sampling
device takes off from agitator.
②Specimen fabrication - After removed foreign substances from sample, it puts the sample into
specimen(Φ50*100mm) as devided 3 times(1/3) then to be Underwater Curing after h
harden the sample many times.
③Unconfined compressive strength test - by professional facility(7, 28days)

10. Method Statement of D. C. M
5. D.C.M <Deep Cement Mixing Method >
(1)Cement mixing ratio
For decision of cement mixing ratio per each soil condition, first of all, mixing test thatis
satisfied on design foundation strength should be conducted
①Mixing : 250kg/m3
mixing, W/C: 0.8:1
②Curing period : 7days strength measurement (compressive strength test)
28days strength measurement (compressive strength test)
(2)Mixture sheet per Mixer Plant Batch
(3)Equipment Setting
DCM Barge is located on position using G.P.S system. Operating is conducted by computer system
in wheel room using winch lever with watching computer monitor. After completed setting on po-
sition. After competed setting on position, winch is fixed.
Cement
1.0
500kg
Classification
Ratio
Weight
Water
0.8
400kg

11. Method Statement of D. C. M
(4)Drilling, Agitation dropping
Slurry is gradually injected as speed of 1~4m/min when agitation rod reach on hoe bottom after
drilling. Rod will be dropped with agitation since auger relay gauge is more than 300A.
Plant operator check cement mixing ratio(W/C is based on specification) and mixing codition of
Agitator, pumping, flowmeter and condition of slurry injection on DCM barge.

12. Method Statement of D. C. M
(5)Slurry injection & Agitation rising
Operator check bottom and inject slurry on bottom for 2~3 minuts. As speed of 1~4m/min, rod is pul-
ing, at the same time cement past is to be injected and agitated.
Plant operator check slurry injection, agitation, pump pressure on pulling, flowmeter recorder.
Before 30cm of reaching at designed bottom,re-penetration start at bottom in accordance with repea-
ted process
(6)Cleaning
After worked, agitator, hose and inside of rod are cleaned.
After complete the deep mixing disposal, A operater sets rod end at a depth of 50cm~1m from the
ground and clean using pump.
Slurry pipes and Slurry in the inside of rod are disposaled on the ground.

13. Method Statement of D. C. M
(7)Slime
①slime dredge : After complete construction, use a back+bargeor a grab barge.
(dredge after survey water depth)
(8)Comfirmation Boring
Collect improvemented sample by DCM at the completed part by using investigation equipments.
Set on the position appointed by construction supervision by using the barge or SEP barge that is
equipment for investigating the sea and check that construction conditions and improvemented sampl-
e's homogeneity by collecting homogeneity and N of improvemented sample by testing S.P.T every 3
meter during collecting improvemented sample to judge the strength of improvemented sample.
(implement the S.P.T test because the lengthof boring rod become 3 meters.)

16. Method Statement of D. C. M
7. Equipment
for Auger motor operation
torque:4,730kgfm
Description Purpose
for transportation of bulk cement
DCM Barge 4 axles auger *3rows
9
2
for Bulk cement dosposal and keeping
6 for bulk cement transportation
for solenoid valve and cleaning
for transportation of slurry
12
1
for checking of slurry
for setting DCM barge
57.6*23*3.6m
240hp
Silo
12
20ton
Tug boat
15ton
Item
for winch
Q'ty
1
3
Working platform
Auger
Generator
DCM Barge
Gear Box
3
1.0:1
640kw
160L/min
60ton
3500hp
750hp
320kw
50ton
26m3
/min
Flowmeter
Compressior
Barge
Pump
5ton
Winch for setting DCM barge
1
Remark
3 Driling 4 axles *3rows
90kw
1 for plant and silo
controll for rod speed
3
1
5
5

17. Method Statement of D. C. M
Jet Pump
60ton Silo Flowmeter
50Ton Silo

18. Method Statement of D. C. M
<Arrangement of DCM barge>

21. Method Statement of D. C. M
9. Material & Management
1)Material investment plan
- Bulk Cement : Supply by Main contractor
- Water : Using seawater
2)Material management plan
(1)BULK : Make it a rule to store in silos after all bulks carried in site are checked quantity
3)Cement for carrying plan
(1)Land transport : Use a car of BULK transportation and transport it
(2)Sea transport : Board portable silos to a barge and supply to silos of plant barge
(3)BULK quantity for carrying : 110TON ~ 120TON / 1 times
10. Environment Management
1)Nastiness barrier installation plan

23. Method Statement of D. C. M
· Waste matter disposal plan
- Wastes occuring in site are collected separately and make it a rule that combustible
wastes must be incinerated and imcombustible wastes must be reclaimed.
- Distinguish between renewable and nonrenewable so it must be disposed according to the
standards and methods of waste disposal.
- General industry wastes are distinguished and they shouldn't be fluttered and flew out
and smelled bad. Private tanks, containers and pipes are used in case that liquid or
liquidity industry wastes are collected and transported.
- Industry waste units, recycling, use conditions and disposal performances are recorded on
industry waste registers and they are maintained for 5 years.
④The environment check
· All of manager plan to protect environment pollution before working every day, all factot of
pollution and waste are disposed based on disposal standard.
· The manager must be always deployed during the incineration in site and disposes incinerated
wastes after complete incineration.
· The wastes occurred while working are checked so that they can't be dropped to workings or
the sea, and it must be managed to equip separate garage collection boxes.
· Using oil, you always used oilpans and remove it immediately with an absorbent or an oil
additive during spill.
5)Waste oil pollution supervision plan
· An oil absorbent exclude the water and remove oil by absorbing oil optionally.
It is used when a efflux is few or a thin oil film is collected. An absorbent has a sort
that absorbs oil and coats oil on the surface. In general, an absorbent is used in the final
stage to prevent disaster, or to collect a thin oil film at the areas which is difficult to
approach by ship, in case that it is difficult to prevent disaster with other methods at the
areas like a spawning ground or a swamp. The absorbent(0.5~1hr later after throw)that absorbs
oil fully must be collected and if not, it will be inferior to what we don't use.

24. Method Statement of D. C. M
· When there is an oil spill, oil should be collected by using an absorbent or an oil reclaimer
, but the case which inject chemicals can take place according to the situations.
The main case is that an oil film spread thinly since it is a long time from the spill or
an oil film is formed thinly since an efflux is few from the beginning and collecting oil
physically is very ineffective in that case.
In that case, after disperse oil into water with chemicals, dispersing agent is the most used
to remove naturally by purifying effects.
As it atomize oil, if oil and seawater mix, oil can be removed more effective than collecting
oil physically since microbial decomposition, evaporation and oxidation with sunshine take
place actively.

30. Method Statement of D. C. M