1. Compaction
‫الدمك‬
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2. Compaction Effect
Air
Water Water
Air
Solid Solid
Loose soil Compacted soil
‫تربة سائبة‬ ‫تربة مدموكة‬
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3. Compaction Advantages
‫مزايا الدمك‬
 As compaction increases, the
following occurs:
 Increasebearing capacity
‫ زيادة قدرة تحمل التربة‬
 Decrease potential for settlement
‫ تقليل إمكانية الهبوط‬
 Reduction in hydraulic conductivity
‫ تقليل نفاذية التربة‬
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4. ?What is compaction
A simple ground improvement technique, where the
soil is densified using external compactive effort.
Densification is done through reducing voids.
‫الدمك: هو طريقة بسيطة لتحسين خواص التربة حيث يتم زيادة كثافتها‬
‫باستخدام جهد دمك خارجى. وزيادة الكثافة يتم عن طريق تقليل حجم‬
Compactive .‫الفراغات‬
effort
+ water =
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5. ?What is compaction
The object of compaction is to improve
the properties of the soil that is used as
sub grade material for roads, fills of
dams, embankments or under shallow
foundations.
‫يهدف الدمك إلى تحسين خواص التربة المستخدمة فى‬
‫كطبقة أساس فى الطرق والمواد المستخدمة فى‬
‫السدود والجسور وكتربة إحلل أسفل الساسات‬
.‫السطحية‬
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6. Purpose of Compaction?
 The compaction of soils and fills will result in
improving the shear strength and reduce
permeability and settlements.
‫ يهدف الدمك لتحسين مقاومة القص وتقليل النفاذية‬
‫والهبوط‬
 Field compaction of soil is assessed in terms
of the dry density of the soil, which is the
weight of soil solids per unit bulk volume.
‫ يتم تقييم الدمك الحقلى باستخدام قيمة وزن وحدة‬
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.‫الحجوم الجاف‬
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7. Relationship between γ dry and γ bulk
Ww
wc =
Wd
air Ww + Wd W
1 + wc = =
water ww wc Wd Wd
V
W
soil Wd =
wd 1 1 + wc
Wd W γb
γd = = =
V ( 1 + wc )V 1 + wc
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8. Laboratory Compaction Test
- To obtain the compaction curve and define
the optimum water content and maximum dry
density for a specific compactive effort.
‫-يتم إجراء الختبار لتحديد محتوى المياه المثل‬
.‫وأقصى كثافة جافة وذلك تحت تأثير جهد دمك محدد‬
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9. Standard Proctor Compaction Test
 The standard was originally developed to
simulate field compaction in the lab, for
small and medium loads.
 Standard Proctor ‫اختبار بروكتور القياسى‬
 Mold: 945 (1000 cm3) or 1/30 ft3 ‫حجم القالب‬
 Hammer: 2.50 Kg or 5.50 lb hammer
‫ وزن المطرقة 05.2 كجم‬
 Drop Height = 30 cm or 12” ‫ارتفاع السقوط03 سم‬
 No. of Soil Layers = 3 ‫عدد الطبقات3 طبقات‬
 No. of Blows = 25 layer 25 ‫ضربة لكل طبقة‬
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10. Modified Proctor Test
 The modified was developed to simulate
larger compaction effort for more serious
loads and bigger equipment
 Modified Proctor ‫اختبار بروكتور المعدل‬
 Mold: 945 (1000 cm3) or 1/30 ft3
 Hammer: 4.50 Kg or 10 lb hammer
‫ وزن المطرقة = 05.4 كجم‬
 Drop Height = 45 cm or 18” ‫ارتفاع السقوط54 سم‬
 No. of Soil Layers = 5 ‫عدد الطبقات5 طبقات‬
 No. of Blows = 25 layer ‫عدد الضربات52 ضربة‬
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11. Specification for Field Compaction
 Relative to what?
 Proctor Test – standard or modified
 % Relative Compaction ‫نسبة الدمك‬
γ d ( field )
R( %) = × 100 R ~ (95 – 100%)
γ d max ( lab )
 If R > 95%, the compaction is accepted in
most cases. ‫أكبر من59% ناجحة‬
 R > 98% could be required in some cases.
 R > 100% could be reached.
.‫ ممكن أن تزيد نسبة الدمك عن 001% فى بعض الحالت‬
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12. Zero Air Voids Line
γd max Modified Proctor Test
Dry Density, γ d
γd max Standard Proctor Test
Rock Breaker
O.M.C O.M.C Water Content, wc
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13. Required Equipment Add pre-measured amounts
and tools of water to soil sample
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14. Mix Sample thoroughly Put mixed soil in mold in
3 layers (Standard Proctor)
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15. Modified Proctor Test
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16. Compact each layer using Remove collar and trim
Rammer, 25 blows per layer the top
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17. Weigh mold and sample
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18. Take Samples for wc
Extrude the sample
determination
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19. Field Compaction
Hand Held Vibrating Plates
 for compacting very small areas
 effective for granular soils
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20. Vibratory Roller
For very thin lifts and small areas
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21. Smooth-wheel roller
Compacts effectively only to 200-300 mm;
therefore, place the soil in shallow layers (lifts)
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22. Pneumatic Rubber Tired Roller
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23. Sheep foot Roller
 Provides kneading action; “walks out” after compaction
 Very effective on clays
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24. Impact Roller
 Provides deeper (2-3m) compaction. e.g., air field
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25. FIELD COMPACTION TESTS
 1- Sand Cone Test.
.‫ 1- اختبار المخروط الرملى‬
 2- Rubble Balloon Test.
.‫ 2- اختبار البالون المطاطى‬
 3- Nuclear Test.
.‫ 3- اختبار بالطرق النووية‬
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26. Sand Cone Test
‫اختبار المخروط الرملى‬
 Performed in the Field.
.‫ اختبار للدمك يجرى فى الموقع‬
 Using sand cone and uniform (standard) sand.
.‫ يتم باستخدام جهاز المخروط والرمل القياسى‬
 Uniform sand: Passing through sieve No. 20 and
retained on No. 40
20 ‫ رمل منتظم الحبيبات هو المار من منخل رقم‬
.40 ‫والمحجوز على منخل رقم‬
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27. Field Measurement of Compaction
Sand Cone
‫المخروط الرملى‬
W
V
γd,field = W / V
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28. Measurement of Field Compaction
 Most common methods are
 Nuclear Method
 Sand Cone method
 Rubber Balloon method
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29. Modified Proctor Test
Rock Breaker
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30. Rock Breaker
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31. Rock Breaker
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32. Rock Breaker
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33. Rock Breaker
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34. Rock Breaker
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35. Rock Breaker
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36. Rock Breaker
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37. Rock Breaker
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38. Rock Breaker
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39. Rock Breaker
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40. Soil Compaction
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