TRANSMISSION CONSTRUCTION STANDARD
9.0
TCS-Q-113.02, Rev. 0
SELECTION AND TYPES OF CONTROLLED FILL MATERIALS
Controlled fill shall be free of organic matters, rubbles, cobbles and boulders, and other
deleterious substances.
9.1
Types of Controlled Fill
The following four (4) types of controlled fills are classified for earthworks.
9.1.1
9.1.2
General Fill (Class D) shall meet the following gradation requirements:
a.
Maximum particle size = 100 mm
b.
Between 80% and 40% by weight passing the 2.0 mm mesh sieve
c.
Not more than 15% by weight passing the 75 micron mesh sieve; less
than 4 plasticity index. Where binding effect is required between soil
particles as in uncontained embankments, a maximum of 20% by
weight material passing the 75 micron mesh sieve shall be provided.
Select Fill shall be a well graded granular material as shown in Table-I.
Table-I
USA Standard Sieve
Size (mm)
Percent Passing
50
100
19.0
95 to 80
2.0
80 to 50
0.250
50 to 25
0.075
20 to 5
Where free draining properties of the controlled fill are essential, such as
groundwater table being within 1.5 m depth below the bottom of foundations
or pavements, the material passing the 75 micron mesh sieve shall be between
5% and 10% by weight. Where groundwater is not a problem and binding
effect is required between soil particles, as in uncontained embankments and
surfaces exposed to erosion, near maximum limit of 20% by weight material
passing the 75 micron mesh sieve shall be provided.
TCSQ11302R0/SZA
Date of Approval: Apirl 10, 2006
PAGE NO. 14 of 46
TRANSMISSION CONSTRUCTION STANDARD
9.1.3
TCS-Q-113.02, Rev. 0
Clean sand satisfying the following USA Standard sieve size gradation shall
be used for bedding around utilities as shown in Table II.
Table II
USA Standard Sieve Size (mm)
4.75
2.00
0.425
0.250
0.075
9.1.4
Aggregate sub-base and base course materials shall meet the following
gradation as shown on Table III and physical properties as shown on Table
IV.
Table III
Sieve
Size
(mm)
101.6
63.5
50.8
38.1
25.4
19.0 *
12.7
9.51
4.76
2.00
0.425
0.250
0.075
Percent Passing
100
95 to 80
80 to 40
60 to 20
Less than 10
GRADATION
Sub-base Material Classes
CLASS A
CLASS B
CLASS C
Well graded Uniform mixture of Well
gravel with gravel and/ or stone graded
sand & silt
fragments
with sand gravel
sand, silt and clay
100
90 - 100
100
70 - 100
100
55 - 85
50 - 80
40 - 70
35 - 70
30 - 60
20 - 50
80 max.
10 - 30
0 - 15
5 - 15
15 max.
Base Course Material Classes
CLASS A
CLASS B
Mixture of all
Uniform
aggregate
mixture of
uniformly graded
crushed rock or
from coarse to fine crushed gravel
100
90 - 100
60 - 90
100
42 - 77
60 - 100
35 - 70
55 - 85
25 - 60
15 - 40
35 - 60
10 - 26
25 - 50
5 - 15
15 - 30
2-9
8 - 15
* If less than 30% of the sample is retained on a 19 mm sieve, Moisture-Density Relations of
soils shall be tested in accordance with ASTM D1557, Method C. If the retained sample on a
19 mm sieve is 30% or more, tests shall be as per AASHTO T-180, Method D
TCSQ11302R0/SZA
Date of Approval: Apirl 10, 2006
PAGE NO. 15 of 46
TRANSMISSION CONSTRUCTION STANDARD
TABLE IV
PHYSICAL PROPERTIES
PHYSICAL
REQUIREMENTS
Sub-base Material
CLASS CLASS CLASS
A
B
C
Base Course Material
CLASS
CLASS
A
B
Liquid Limit (Max %)
-
25
25
-
25
Plasticity Index (Max %)
-
6
6
6
4-8
Sand Equivalent (Min %)
25
25
25
30
50
Loss by abrasion (Max %)
50
50
50
40
40
-
-
-
5
5
Thin and elongated pieces, by
weight (larger than 25 mm,
thickness less than 1/5 length)
as per ASTM D 4791
(Max %)
9.2
TCS-Q-113.02, Rev. 0
Friable Particles (Max %)
Soundness Test using MgSO4
(Max. %)
Coarse Aggregate
-
-
-
0.25
0.25
18
18
18
18
18
Fine Aggregate
20
20
20
20
20
Requirements of Controlled Fill Materials
The COMPANY Representative shall approve the depth of the fill after the
availability of soil reports. Aggregate sub-base and base courses, if specified, shall
be used as fill material for access roads, substation yards, designated roadways,
parking lots, and material yards where heavy traffic load is expected.
Controlled Fill materials shall be required up to 1.0 m of the bottom elevation of
foundations, concrete sidewalks/pavements, slabs on grade, and asphalt concrete
surface/binder courses depending on the existing sub-grade soil condition.
Minimum depth of filling shall be 600 mm if the bottom of excavation reveals good
soil/ hard surface.
Sand shall be used for bedding around service lines such as pipes, conduits, and
cables. In all other instances, “General Fill” shall be used as sub-base unless
otherwise specified.
TCSQ11302R0/SZA
Date of Approval: Apirl 10, 2006
PAGE NO. 16 of 46
TRANSMISSION CONSTRUCTION STANDARD
9.3
TCS-Q-113.02, Rev. 0
Acceptance of Controlled Fill Materials
Fifty kilogram bag samples of each material to be used as controlled fill shall be
collected in the presence of COMPANY Representative and submitted for testing to
an independent soil testing laboratory, approved by the COMPANY, at least ten
(10) days prior to commencing controlled fill operations. The testing laboratory
shall perform at least one of each of the following tests on fill samples and submit
the test results to the COMPANY.
i.
Mechanical analysis (Gradation), ASTM D 422
ii.
Plasticity Index, ASTM D 4318
If the results from the above tests meet the specification requirements, the testing
laboratory shall determine the CBR, Sulphate and chloride content including the
compaction characteristic of the fill material by conducting one of the following tests
(item a or b below) that is applicable to the gradation, plasticity and drainage
characteristics of the fill material:
a.
Modified Compaction, ASTM D 1557, Method D, Minimum of Five
Moisture Density Determinations per Test for soils containing more than
15% materials passing the 75 micron sieve; or
b.
Maximum and Minimum Index Density of Soils and Calculation of Relative
Density, ASTM D 4253 and D 4254 for free draining soil containing less
than 15% non-plastic materials passing the 75 micron sieve.
c.
The California Bearing Ratio (CBR) for each class of fill materials
compacted in the laboratory after four (4) days soaking as determined by
ASTM D 1883 shall be as follows:
Table V
Material
Class
CBR Values
Sub-base
Class A, B, C
Class D (General Fill)
Not less than 50
Not less than 15
Base Course
Class A & B
Not less than 100
Note: The correlation of the soil ratings based on CBR values is given in
Figure 8.
TCSQ11302R0/SZA
Date of Approval: Apirl 10, 2006
PAGE NO. 17 of 46
TRANSMISSION CONSTRUCTION STANDARD
d.
TCS-Q-113.02, Rev. 0
The Sulfate and chloride contents of controlled fill for each class of fill
materials shall also be determined. Borrowed fill with greater Sulfate or
chloride content than the existing soil in the site shall not be used as
controlled fill for improvement of existing facility.
No material shall be used as a controlled fill until it is tested, as above, by the
soil testing laboratory, and approved by the COMPANY Representative.
Changes in the controlled fill material may be made when characteristics of
materials, job conditions, weather, test results or other circumstances warrant.
Each time, a change in fill material has to take place, the new material shall
be tested as above and test results submitted to COMPANY Representative
for approval and acceptance before using in the work. A change in controlled
fill material and related tests shall be planned so as to avoid construction
delays.
Final acceptance of controlled fill material rests with the COMPANY
Representative, whose decision shall be final and binding.
TCSQ11302R0/SZA
Date of Approval: Apirl 10, 2006
PAGE NO. 18 of 46