2. Compaction Effect
Air
Water Water
Air
Solid Solid
Loose soil Compacted soil
تربة سائبة تربة مدموكة
Soil Compaction
04/05/12 2
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
Soil Compaction
04/05/12 3
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 =
Soil Compaction
04/05/12 4
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
Soil Compaction
04/05/12 5
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
04/05/12
.الحجوم الجاف
Soil Compaction
6
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
Soil Compaction
04/05/12 7
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
Soil Compaction
04/05/12 8
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
Soil Compaction
04/05/12 9
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
Soil Compaction
04/05/12 10
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
Soil Compaction
04/05/12 11
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
Soil Compaction
04/05/12 12
13. Required Equipment Add pre-measured amounts
and tools of water to soil sample
Soil Compaction
04/05/12 13
14. Mix Sample thoroughly Put mixed soil in mold in
3 layers (Standard Proctor)
Soil Compaction
04/05/12 14
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
Soil Compaction
04/05/12 26
27. Field Measurement of Compaction
Sand Cone
المخروط الرملى
W
V
γd,field = W / V
Soil Compaction
04/05/12 27
28. Measurement of Field Compaction
Most common methods are
Nuclear Method
Sand Cone method
Rubber Balloon method
Soil Compaction
04/05/12 28