CEE451
Geotechnical Engineering-III
Credit: 02
Md. Nazmul Islam Rafi
Lecturer
Civil and Environmental Engineering
Shahjalal University of Science and Technology
CONTENTS TO BE COVERED
Specifications and design Analysis and design of
01 of field compaction 02
sheet pile
Fundamentals of Pile subjected to lateral
03 04
machine foundation load
Md. Nazmul Islam Rafi
References
Principles of Geotechnical Engineering
Textbook by Braja M Das
Section: 6.3-5, 6.10-11
Go through these sections for a better understanding.
Md. Nazmul Islam Rafi 3
Types of laboratory test
Md. Nazmul Islam Rafi 4
Types of laboratory test
Aspect Standard Proctor Test Modified Proctor Test
Determine optimal moisture content and
Determine optimal moisture content and
maximum dry density for heavier
Purpose maximum dry density for compaction of
compaction efforts, typically used for
soils
road construction and heavy structures
Soil is compacted in three layers using a Soil is compacted in five layers using a
2.5 kg hammer dropped from a height of 4.5 kg hammer dropped from a height of
Test procedure
12 inches, each layer receiving 25 blows 18 inches, each layer receiving 25 blows
(Energy: 306.5 J) (Energy: 830.4 J)
Volume of mold: 1/30 cubic feet Volume of mold: 1/30 cubic feet
Mold dimensions
(944 𝑐𝑚3 ) (944 𝑐𝑚3 )
Hammer weight 2.5 kg (24.5 N) 4.5 kg (44.1 N)
Md. Nazmul Islam Rafi 5
Types of laboratory test
Aspect Standard Proctor Test Modified Proctor Test
Hammer drop height 12 inches (30.5 cm) 18 inches (45.7 cm)
Blows per layer 25 25
Number of layers Three Five
Less severe, used for lighter More severe, used for heavier structures
Compaction effort
structures and fills and road construction
Typically yields higher maximum dry
Typically yields lower maximum dry
density and lower optimum moisture
Results interpretation density and higher optimum moisture
content compared to modified
content compared to standard Proctor test
Proctor test
Md. Nazmul Islam Rafi 6
Proctor Tests
14.3 mm
diameter
(4.5 in.)
Extension
Drop 304.8
mm (12 in.)
16.43 mm
(4.584 in.)
Mass of
hammer 2.5
kg (Weigh
5.5 lb)
01.6 mm
diameter 50.8 mm
(4 in.) (2 in.)
Md. Nazmul Islam Rafi 7
Proctor Tests
The energy values are calculated using the 14.3 mm
formula: diameter
Energy = Mass * Gravity * Drop Height (4.5 in.)
Where:
• Mass is the weight of the hammer Extension
• Gravity is the acceleration due to gravity Drop 304.8
• Drop Height is the height from which the mm (12 in.)
hammer is dropped (in meters)
These energy values give an indication of 16.43 mm
the force exerted on the soil during (4.584 in.)
compaction, which is an important factor in Mass of
hammer 2.5
determining compaction characteristics. kg (Weigh
5.5 lb)
01.6 mm
diameter 50.8 mm
(4 in.) (2 in.)
Md. Nazmul Islam Rafi 8
Compaction Specifications
Design specifications (Target Properties)
• For sands and gravels: relative density (Dr)
• For fine-grained soils: relative compaction (R) and soil
moisture content 𝛾𝑑(𝑓𝑖𝑒𝑙𝑑) − 𝛾𝑑(𝑚𝑖𝑛) 𝛾𝑑(𝑚𝑎𝑥)
𝐷𝑟 = ∗
𝛾𝑑(𝑚𝑎𝑥) − 𝛾𝑑(𝑚𝑖𝑛) 𝛾𝑑(𝑓𝑖𝑒𝑙𝑑)
Prescriptive specifications (Verification Method)
Contractor builds a test pad to establish the compaction effort
required to achieve specified target properties. 𝛾𝑑(𝑓𝑖𝑒𝑙𝑑)
𝑅 (%) = ∗ 100
𝛾𝑑(𝑚𝑎𝑥−𝑙𝑎𝑏)
This includes:
• Compaction equipment
• Thickness of soil layers
• Number of compactor passes
• Soil water content
Md. Nazmul Islam Rafi 9
Types of Fill
Gravel:
• Gravel (e.g. GW, GP, GW-GC, GC). These labels refer to the
Unified Soil Classification System (USCS) groups for gravel
which include well-graded gravel (GW), poorly-graded gravel
(GP), well-graded gravel with some clay or sand (GW-GC),
and clayey gravel (GC).
Sand:
• Sand (SW, SP, SP-SM, SC) which could be included in coarse-
grained fills depending on the project requirements.
• These labels correspond to USCS groups for sand including
well-graded sand (SW), poorly-graded sand (SP), poorly-
graded sand with some silt or clay (SP-SM), and clayey sand
(SC).
Md. Nazmul Islam Rafi 10
Example 6.9
Md. Nazmul Islam Rafi 11
Example 6.9
Laboratory compaction test results for a clayey silt are given in
the following table.
Following are the results of a field unit-weight Moisture Dry unit weight
determination test performed on the same soil by means content (%) (𝒌𝑵/𝒎𝟑 )
of the sand cone method:
6 14.80
• Calibrated dry density of Ottawa sand = 1570 𝑘𝑔/𝑚3 8 17 45
• Calibrated mass of Ottawa sand to fill the cone = 0.545 𝑘𝑔 9 18.52
• Mass of jar + cone + sand (before use) = 7.59 𝑘𝑔 11 18.9
• Mass of jar + cone + sand (after use) = 4.78 𝑘𝑔
12 18.5
• Mass of moist soil from hole = 3.007 𝑘𝑔
14 16.9
• Moisture content of moist soil = 10.2%
Determine:
a. Dry unit weight of compaction in the field
b. Relative compaction in the field
Md. Nazmul Islam Rafi 12
Example 6.9
Part a: In the field,
Mass of sand used to fill the hole and cone = 7.59 𝑘𝑔 −
4.78 𝑘𝑔 = 2.81 𝑘𝑔
Mass of sand used to fill the hole = 2.81 𝑘𝑔 − 0.545 𝑘𝑔 =
2.265 𝑘𝑔
2.265 𝑘𝑔
Volume of the hole (V) = 𝐷𝑟𝑦 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑂𝑡𝑡𝑎𝑤𝑎 𝑠𝑎𝑛𝑑
2.265 𝑘𝑔
= 3
= 0.0014426 𝑚3
1570 𝑘𝑔/𝑚
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑚𝑜𝑖𝑠𝑡 𝑠𝑜𝑖𝑙
Moist density of compacted soil = 𝑉𝑜𝑙𝑢𝑚𝑒𝑜𝑓 ℎ𝑜𝑙𝑒
3.007
= = 2084.4 𝑘𝑔/𝑚3
0.0014426
Md. Nazmul Islam Rafi 13
Moisture Dry unit weight
Example 6.9 content (%) (𝒌𝑵/𝒎𝟑 )
6 14.80
8 17 45
9 18.52
Moist unit weight of compacted soil = 11 18.9
(2084.4)(9.81)/1000 = 20.45 𝑘𝑁/𝑚3 12 18.5
14 16.9
Hence,
𝛾 20.45
𝛾𝑑 = = = 18.56 𝑘𝑁/𝑚3
𝑤(%) 10.2
1 + 100 1 + 100
Part b:
The results of the laboratory compaction test are plotted in
Figure. From the plot, we see that 𝛾𝑑(𝑚𝑎𝑥) = 19 𝑘𝑁/𝑚3 .
Hence,
𝛾𝑑(𝑓𝑖𝑒𝑙𝑑) 18.56
𝑅= = = 97.7 %
𝛾𝑑(𝑚𝑎𝑥) 19.0
Md. Nazmul Islam Rafi 14
Example 6.10
Md. Nazmul Islam Rafi 15
Example 6.10 Moisture
Table 1
Dry unit weight
content (%) (𝒌𝑵/𝒎𝟑 )
12 16.34
For a given soil ( 𝐺 = 2.72 ), following are the results of 14 16.93
compaction tests con ducted in the laboratory (Table 1). 16 17.24
18 17.20
After compaction of the soil in the field, sand cone tests 20 16.75
(control tests) were conducted at five separate locations. 22 16.23
Following are the results (Table 2):
The specifications require that Table 2
• 𝛾𝑑 must be at least 0.95𝛾(𝑚𝑎𝑥) Loca Moisture Moist
• Moisture content 𝑤 should be within ±2% 𝑜𝑓 𝑤𝑜𝑝𝑡 tion content density,
𝒘(%) 𝛒(𝒌𝒈/𝒎𝟑 )
Make necessary calculations to see if the control tests meet the 1 15.2 2055
specifications. 2 16.4 2060
3 17.2 1971
4 18.8 1980
5 21.1 2104
Md. Nazmul Islam Rafi 16
Moisture 𝜸𝒛𝒂𝒗 (𝒌𝑵/𝒎𝟑 )
content (%)
Example 6.10 12 20.12
14 19.33
16 18.59
18 17.91
Here, 20 17.28
𝛾𝑤
𝛾𝑧𝑎𝑣 = 22 16.70
1
𝑤+𝐺
𝑠
Given 𝐺𝑠 = 2.72. Now the following table can be prepared.
The graph shows the plot of 𝛾𝑑 and 𝛾𝑧𝑎𝑣 . From the plot, it
can be seen that
Md. Nazmul Islam Rafi 17
Example 6.10
Moisture 𝜸𝒛𝒂𝒗 (𝒌𝑵/𝒎𝟑 )
content (%)
12 20.12
14 19.33
16 18.59
18 17.91
20 17.28
22 16.70
Md. Nazmul Islam Rafi 18
Moisture 𝜸𝒛𝒂𝒗 (𝒌𝑵/𝒎𝟑 )
content (%)
Example 6.10 12 20.12
14 19.33
16 18.59
18 17.91
Here, 20 17.28
𝛾𝑤
𝛾𝑧𝑎𝑣 = 22 16.70
1
𝑤+𝐺
𝑠
Given 𝐺𝑠 = 2.72. Now the following table can be prepared.
The graph shows the plot of 𝛾𝑑 and 𝛾𝑧𝑎𝑣 . From the plot, it
can be seen that
𝛾𝑑(𝑚𝑎𝑥) = 17.4 𝑘𝑁/𝑚3
𝑊𝑜𝑝𝑡 = 16.8%
Md. Nazmul Islam Rafi 19
Loc 𝒘(%) 𝛒(𝒌𝒈 𝛾𝑑∗ (𝒌𝑵
Example 6.10 ati
on
/𝒎𝟑 ) /𝒎𝟑 )
1 15.2 2055 17.5
2 16.4 2060 17.36
Based on the specifications, 𝛾𝑑 must be at least 3 17 2 1971 16.51
0.95𝛾𝑑(𝑚𝑎𝑥) = 0.95 17.4 = 16.54 𝑘𝑁/𝑚3 4 18.8 1980 16.35
5 21.1 2104 18.41
Moisture content, 𝑤 is to be within 16.8% ±
2% = 14.8% 𝑡𝑜 18.8%.
For the control tests, the following table can
be prepared.
Md. Nazmul Islam Rafi 20
Example 6.10
Based on the
specifications, 𝛾𝑑 must be
at least 0.95𝛾𝑑(𝑚𝑎𝑥) =
0.95 17.4 = 16.54 𝑘𝑁/
𝑚3
Moisture content, 𝑤 is to
be within 16.8% ± 2% =
14.8% 𝑡𝑜 18.8%.
Md. Nazmul Islam Rafi 21
Example 6.10
The results of the control
tests are also plotted in
Figure 6.30. From the
plot, it appears that the
tests at locations 1 and 2
meet the specifications.
The test at location 3 is a
borderline case. Also
note that there is some
error for the test in
location 5, since it falls
above the zero-air-void
line
Md. Nazmul Islam Rafi 22
Class Work
Md. Nazmul Islam Rafi 23
Example 6.10 Moisture
Table 1
Dry unit weight
content (%) (𝒌𝑵/𝒎𝟑 )
12 16.31
For a given soil ( 𝐺 = 2.7 ), following are the results of 14 16.91
compaction tests con ducted in the laboratory (Table 1). 16 17.34
18 17.25
After compaction of the soil in the field, sand cone tests 20 16.85
(control tests) were conducted at five separate locations. 22 16.20
Following are the results (Table 2):
The specifications require that Table 2
• 𝛾𝑑 must be at least 0.93 𝛾(𝑚𝑎𝑥) Loca Moisture Moist
• Moisture content 𝑤 should be within ±2% 𝑜𝑓 𝑤𝑜𝑝𝑡 tion content density,
𝒘(%) 𝛒(𝒌𝒈/𝒎𝟑 )
Make necessary calculations to see if the control tests meet the 1 15.2 2068
specifications. 2 16.4 2075
3 17.2 1961
4 18.8 1985
5 21.1 2116
Md. Nazmul Islam Rafi 24
Thank You
Do you have any question?
