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Ms. Adilen @ Lucia Suil

adilen@polikk.edu.my

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1.4. DRAINAGEType of water:-

Surface water rainwater which have been

accumulated at the earths surfaceGround water - begins with rain and snowmeltthat seeps or infiltrates into the ground. Theamount of water that seeps into the ground varieswidely from place to place according to the type of

land surface that is present. In porous surface materialthat water readily seeps through, such as sand orgravel, 40 to 50 %of the rain and snowmelt may seepinto the ground.

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1.4.1. Ground Water DrainagePurpose:

To improve discharge water inside the

ground so that water level will always at thelower level and go deep below the surfacearea.

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1.4.1. Ground Water DrainageThe significant/important of discharge water

are:-

III. To improve soil stability

IV. Avoid flooding

V. To avoid higher level of moisture content at

the ground area

VI. To avoid higher level of moisture content atthe constructions surrounding area

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1.4.2. Effects of water to the

soili. Its make excavation works difficult and

costly

ii. Workers safety were disturbiii. Work in wet area and not comfortable

caused low production in work

iv. Framework very hard to install at the

excavated area because the excavationwork is not align (straight), muddy and etc.

v. Wet area can caused water content in thecement also high and the cement strength

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1.4.3. Method of lowering or

discharging underground water level by:

i. Ground water pipe

ii. Pumping method

iii. Well level/well point

iv. Vertical well

v. Geotextile

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i. Ground water pipe

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Surface water cut-off

Coarse

granular

filter

Fine

granular

bedding

Diameter

of pipe

minimum

Back fill

Coarsegranular

filter

Fine

granular

bedding

Perforated pipes as surface and subsoil drains

b.Surface water and ground water drain

c.Ground water drain

(a) (b)

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Pumping methodBuild a temporary drain from where the water

storage and discharge it into the drainage

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