Soil Compaction Topic I Topic I

Success of Embankment Proper preparation of foundation. Use of suitable materials. Proper placing working and compacting of materials. Topic I

Proper Preparation of Foundation Clear and grub area Cut vegetation Remove perishable material Strip and stockpile Compact area Topic I

Suitable Materials Rock Sand Silt Clay See Standard specifications list Topic I

Unsuitable Materials Organic soils should not be used as embankment or subgrade material. Topic I

Proper Placement and Compaction Placing layers Placing in marsh Placing rock Topic I

Placing Layers The maximum thickness of a layer should not exceed 8 inches loosely placed. 8 inch lifts Topic I

Placing Layers Compact each layer Level each layer Parallel Topic I

Placing in Marsh Typically in wet marsh excavations WisDOT allows for marsh backfill to be end dumped into excavation and “surged” down into the excavation with a bulldozer until above water level. Topic I

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Placing Rock No end dumping Bulldozed or shoved into position Various sizes When placing rock all voids must be filled with finer material. Topic I

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Principles of Compaction Decrease future settlements Increase shear strength Decrease permeability Increase stability Topic I

Not Achieving Compaction? Solutions Increase compaction effort Compaction equipment Change soil moisture content Optimum moisture content Topic I

Figure 1: Compaction Equipment Topic I

Figure 1: Compaction Equipment Static smooth drum roller works well for sealing subgrades after the days grading operations are complete. Doesn’t work well on clay soils. Topic I

Standard Compaction Embankment compaction Topic I

Special Compaction Density tests Sand Cone Method Nuclear Method Minimum frequency Topic I

Moisture Control Proper moisture conditions are essential for the efficient compaction of earth embankments. Satisfactory moisture conditions almost always are specified in relation to the optimum moisture content for a standard laboratory compaction test. Topic I

Moisture Control Discs for wet cohesive soils Blade crown on surface Mixed Topic I

Documentation- Cut sections Excavated proper grade Frost susceptible materials Compaction EBS Drainage Proper disposal Topic I

Documentation- Embankments Preparation of foundation Soils utilized Placing and compacting of materials Topic I

Documentation-Entries Soil type Moisture content Layer thickness Drying or wetting Routing pattern Topic I

Earthwork Equipment Hauling Leveling Aerating Compacting Topic I

Figure 2: Track Dozer Topic I

Track Dozer Track Dozers are not to be used as compaction equipment. Used to level lifts of fill. Topic I

Subgrade Care Topic I

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Figure 3:Disc Drying Topic I

Disc Drying Drying of wet soils is necessary and can be accomplished by using graders, discs or harrows. Aeration of the soil Necessary for compaction Topic I

Figure 4: Rubber Tire Dozer Topic I

Rubber Tire Dozer/Scrapers Hauling, Leveling and Compacting Topic I

Figure 5: Sheepsfoot Imprint Topic I

Sheepsfoot Imprint Optimum moisture High volume compaction Lower water content Increase soil surface Cohesive and semi-cohesive soils Topic I

Figure 5: Motor-Grader Topic I

Motor-Grader Aerates and levels Takes out ruts Not for compaction Topic I

Figure 6: Solid Subgrade Topic I

Solid Subgrade Keeps subgrade bladed up. Keeps ruts out. Topic I

Figure 7: Excessive Rutting Topic I

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Excessive Rutting Material too wet Solutions: Motor-grader Tractor Disc Topic I

Figure 8: Embankment construction Topic I

Embankment Construction Equipment Dozer Tamping Roller Motor-Grader Topic I

Figure 9: Dumping and Leveling Topic I

Dumping and Leveling Firm and unyielding support. Prior to first lift. Topic I

Figure 10: Tamping Virbratory Roller Topic I

Tamping Vibratory Roller “Dry”, bony material doesn’t stick. Topic I

Figure 11: Excellent Material Topic I

Excellent Material Dry and granular Some rock Imprints stand out Not common in WI Topic I

Figure 12: Good Conditions Topic I

Good Conditions Back tire of grader is not sinking. Topic I

Figure 13: Scraper End Dumping Topic I

Scraper End Dumping Pushed into wet area. Granular material Seal first lift Don’t trap unstable soil in embankment. Topic I