Name : Abdulrahman Al-bedah ID : KINGDOM OF SAUDI ARABIA KING SAUD UNIVERSITY CIVIL ENGINEERING DEPARTMENT CE DEEP COMPACTION

Outlines 1. Definition. 2. Aims Of Compaction. 3. Methods of Deep compaction. Vibro-Compaction. Vibro-Compaction. Dynamic Compaction. Dynamic Compaction. Blasting. Blasting. 4. References.

Soil Compaction Definition: The method of mechanically increasing the density of soil by expulsion of air voids

Aims Of Compaction: 1. Increases load-bearing capacity. 2. Prevents frost damage. 3. Provides stability. 4. Reduces water seepage, swelling and contraction. 5. Reduces settling of soil.

Methods of Deep compaction  Vibro-Compaction.  Dynamic Compaction.  Blasting.

Vibro-Compaction  Known as “VibroFlotation“.  Is used to densify clean, cohesionless soils.  The action of the vibrator, usually accompanied by water jetting.  Allowing them to move into a denser configuration, typically achieving a relative density of 70 to 85 percent.

Expected Vibro-Compaction Results: Relative Effectiveness Ground Type ExcellentSands Marginal to Good Silty Sands PoorSilts Not applicable Clays

Vibro-compaction Acceptance Testing:  Standard Penetration Test (SPT).  Cone Penetrometer Test (CPT).  Pressuremeter Test (PMT).  Dilatometer Test (DMT).  Load test.

Dynamic Compaction  Dynamic Compaction is the dropping of heavy weights on the ground surface to densify soils at depth. Pounder (Tamper) Mass = tons Drop = ft

Typical Dynamic Compaction Program Involves:  Weights of 10 to 30 tons.  Drop heights of 50 to 100 ft.  Impact grids of 7 x 7 ft to 20 x 20 ft. Important Dynamic Compaction Geotechnical Parameters:  Soil conditions.  Groundwater level.  Relative density.  Degree of saturation.  Permeability.

Important Dynamic Compaction Construction Conditions:  Minimum ft clearance from any structure.  Review site for vibration sensitivity. Dynamic Compaction Acceptance Testing:  Large-Scale Load Test.  Standard Penetration Test (SPT).  Cone Penetrometer Test (CPT).  Pressuremeter Test (PMT).  Dilatometer Test (DMT).  Shear-Wave Velocity Profile.

Blasting Blasting is the process of detonating smallcharges within loose cohesion less soils for the purpose of densification. Blasting is the process of detonating smallcharges within loose cohesion less soils for the purpose of densification.

Expected Soil Behavior with Blasting:  Immediate and long-term surface settlement.  Settlement can be 2-10 percent of treated strata thickness.  Penetration resistance will increase slowly with time for several weeks.  Dense zones may be loosened during blasting.

Design Considerations:  Charges should be placed at approximately 1/2-3/4 of desired depth of compaction.  Spacing of detonation holes should be between 5-15 m.  Successive coverage's are separated by hours or days.  Individual charge 1-12 kg, the amount of total explosive is g/m^3 of treated soil.  Soil closest to the surface will be poorly compacted and may need compaction by another method or removal.  The compaction resulting from blasting is a function of the initial relative density.

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