Method Statement of D. C. M Date Company 7-Apr-11 Boubyan Seaport Project Phase 1 Deep Cement Mixing Method Method Statement of D. C. M 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 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. 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) 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, ②Curing period : W/C: 0.8:1 7days strength measurement (compressive strength test) 28days strength measurement (compressive strength test) (2)Mixture sheet per Mixer Plant Batch Classification Water Cement Ratio 0.8 1.0 Weight 400kg 500kg (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 position. After competed setting on position, winch is fixed. 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. 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 puling, 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 repeated 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. 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 sample'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.) Method Statement of D. C. M 7. Equipment Item Description Q'ty 57.6*23*3.6m 1 Working platform 3 Driling 1.0:1 3 controll for rod speed 640kw 3 for Auger motor operation 320kw 1 for plant and silo 90kw 1 for winch 50ton 9 for Bulk cement dosposal and keeping 60ton 6 for bulk cement transportation Compressior 26m3 /min 2 for solenoid valve and cleaning Pump 160L/min 12 for transportation of slurry 12 for checking of slurry DCM Barge Auger Gear Box Generator Silo 240hp torque:4,730kgfm Flowmeter Purpose 4 axles *3rows Barge 3500hp 1 for transportation of bulk cement Tug boat 750hp 1 for setting DCM barge 20ton 3 15ton 5 5ton 5 Winch DCM Barge Remark for setting DCM barge 4 axles auger *3rows Method Statement of D. C. M 50Ton Silo Jet Pump 60ton Silo Flowmeter Method Statement of D. C. M <Arrangement of DCM barge> 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 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. 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. Method Statement of D. C. M