Earth Work Embankment.

Dear friends, it is only just indications of materials and Tests using in Embankments, for full details please see the MOC General Specification Nov-1998(KSA) Section - 2.05.

Materials and Test frequency According to MOC(MOT)General Specification November 1998 in Kingdom of Saudi Arabia
Reference: Section 2.05

Materials:
Classification of materials A-5 or Better (AASHTO Classification system). In areas subject to flood and prolonged inundation of the embankments, such as at bridge sites,the material used in this areas as A-1-a, A-1-b or A-2-4(AASHTO Classification system)
Imported Borrow Materials:
Borrow sites shall not be located so that any edge is closer than 300 meter from embankment toe of slope unless otherwise shown on the plans.
Imported borrow materials shall not be taken from any area within 500 meter downstream of drainage structure unless approved by the Engineer. such borrow sites shall be back filled and compacted as directed by Engineer.
Preliminary testing of all proposed sources of imported materials for embankment.
(1) Classification - MRDTM 210 (All required tests)
(2) Proctor - MRDTM 212 or MRDTM 214 if apprpriate
(3) California Bearing Ratio(CBR) - MRDTM 213
Logs, trees, stumps, seeds, heavy grass, frozen soil, or other undesirable materials shall not be placed in the layers of embankment.
Dune Sand Embankment:
Construction of embankments with dune sand shall be accomplished in a series of operations as follows,
(1) Edge berms shall first be constructed along both sides of staked embankment, except where the embankment is to be constructed against hillsides or existing embankment, using class A-1 or A-2 soils from road way excavation or borrow which resist erosion by wind and water and are approved by the Engineer. Edge berms shall be constructed with an external side slope as shown on the plans, but not steeper than 1:6( one vertical to six horizontal.Edge berms shall be constructed not more than 40 centimeters in height and not less than 2 meters wide at the top.
(2) Dune sand shall be excavated, hauled, deposited and spread within the edge berms to the full height of the edge berms using any means other than hydraulic sluicing.
The dune sand at all points along the side slopes of the embankment shall be covered with a minimum 2 meter thickness of compacted Class A-1 or A-2 soils which will resist erosion caused by wind and water.
Lift Thickness and Compaction Requirements.
Testing Methods.
(1) Moisture Density Test - MRDTM 212(Adaptation of AASHTO T 180-74)
This method of test is intended for determining the relationship between moisture content and dry density of soils
when compacted according to the described procedures and equipment. For a given compactive effort, a 4.54 kg hammer
dropped 457.2 mm, 56 blows per layer, each soil has a moisture content at which the dry density reaches a maximum value.This density and moisture content generally equates with maximum stability and is therefore used as a density standard to which field determinations are compared. The compactive effort imparted in the test was established to yield densities similar to those which could reasonably be achieved in the field with modern compacting equipment.
* The field density and actual moisture content of the compacted embankment shall be determined by field tests according to MRDTM - 215.
* The maximum dry density as determined by MRDTM 212 shall be adjusted by AASHTO T244 to compensate for differing percentages of coarse particles on the 4.75mm (No.4) sieve in the field density test sample.
* Maximum Density: The maximum dry density as determined by the Moisture density test shall be the density to which the field density is referred for comparison or percentage for each type of soil used in the work.
* Optimum Moisture: The optimum moisture shall be the moisture content corresponding to the maximum density on the moisture density curve.
* Moisture Content Range: The moisture content range shall be limits of moisture content of each 4" of soil with the optimum as a reference.
* Field Density: The field density shall be the density of the compacted embankment determined by the field density test.
* Moisture Content: The moisture content shall be the actual content of the soil in the compacted embankment at the time of compaction.

(2)Relative Density Test: For the cohesion less free draining soils for which impact compaction will not produce a well defined moisture density relationship curve and the maximum density, the test for the relative density of cohesion less soils (MRDTM 214) shall be used to determine the relative density.
Relative density is define as the state of compactness of a soil with respect to the loosest and densest state at which it can be placed by laboratory procedures described in the MRDTM 214.
The field density and actual moisture content of the compacted embankment shall be determined by field tests according to MRDTM 215 and 216, or by nuclear method MRDTM 218.
* Relative Density: The relative density as determined by the relative density test shall be the standard to which the field density is referred for comparison for each type of cohesion less soil used in the work.
* Field Density: The field density shall be the density of the compacted embankment determined by the field density test.
* Moisture Content: The moisture content shall be the actual content of the soil in the compacted embankment at the time of compaction.
* Borderline Materials: In cases where borderline materials are encountered, both methods will be utilized and the method which results in the higher laboratory maximum density shall be used as the standard to which the field density is compacted.
* Plate Load Test: In addition ti the moisture density test and the relative density test, the compaction of earthwork may also be checked by a plate load test (German method). this method is described in MRDTM 237A. The test shall be applicable for all soils but not rockfill. Use of the plate load test for Dune sand (A-3) shall be encouraged.

Earth Embankment Lift Thickness and Compaction Requirement:
* Type 98: Compacted density of the soil shall be equal or greater than 98% of maximum density or 76% of relative density.
* Type 95: Compacted density of the soil shall be equal or greater than 95% of maximum density or 74% of relative density.
* Type 90: Compacted density of the soil shall be equal or greater than 90% of maximum density or 70% of relative density.
* Specific Compaction Requirements:
Sub grade - expressways and major link roads - Type 98
Sub grade - Agriculture roads and link roads - Type 95
Top 60 cm of embankment - Type 95
Bottom portion of embankment - Type 90
Agriculture roads and links embankment - Type 90
Natural ground - Same type compaction requirement as embankment layer above the natural ground
Natural ground-Touch grade - Compaction requirement type 5% less than the compaction requirement type for SG

Special loose lift thickness: for the top 60 cm of the embankment 30 cm lifts may be attempted subject to verified uniform density throughout the full depth of the lift. However A-3, A-6 and A-7 material are not permitted.
For the remaining portion of the embankment:
* Materials type permitted and Lift thickness
* A-1-a, A-1-b and A-2-4 30 cm
* A-4 and A-5 20 cm
* A-3 50 cm

Rock Embankment Lift Thickness and Compaction Requirements:
* Material: The material used for rock-fill embankments shall consist predominantly of rock fragments of such size that material can be placed in layers of the thickness prescribed, conforming the following requirements,
* Maximum particle size - 2/3 loose layer thickness
* Passing 0.6 mm (No.30) sieve - 25% maximum
* Uniformity coefficient - Cu 5 minimum
(Cu = D60/D10, D60-The particle size at which 60% passes and D10-The particle size at which 10% passes)
* The maximum permitted layer thickness shall be related to the unit weight of the vibratory roller used for compaction and shall not exceed 100 centimeter loose measurement.
Maximum thickness of layer (Loose measurement)centimeter - Minimum roller mass on drum (kg/unit width)
40 - 2300 - 2900
60 - 2900 - 3600
80 - 3600 - 4300
100 - 4300 - 5000
** for multiple roller, this shall be assessed on the high axle load.