Name : Name : Abdulrahman Al-bedahAbdulrahman Al-bedahID : ID : 423102910423102910

KINGDOM OF SAUDI ARABIAKINGDOM OF SAUDI ARABIAKING SAUD UNIVERSITYKING SAUD UNIVERSITY

CIVIL ENGINEERING DEPARTMENTCIVIL ENGINEERING DEPARTMENT

CE - 486DEEP COMPACTION

OutlinesOutlines

1.1. Definition.Definition.2.2. Aims Of Compaction.Aims Of Compaction.3.3. Methods of Deep compaction.Methods of Deep compaction.

Vibro-Compaction.Vibro-Compaction. Dynamic Compaction.Dynamic Compaction. Blasting.Blasting.

4.4. References.References.

Soil CompactionSoil Compaction

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

Aims Of CompactionAims Of Compaction::

1.1. Increases load-bearing capacity.Increases load-bearing capacity.2.2. Prevents frost damage.Prevents frost damage.3.3. Provides stability.Provides stability.4.4. Reduces water seepage, swelling and Reduces water seepage, swelling and

contraction.contraction.5.5. Reduces settling of soil.Reduces settling of soil.

Methods ofMethods ofDeep compactionDeep compaction

Vibro-Compaction.

Dynamic Compaction.

Blasting.

Vibro-CompactionVibro-Compaction Known as “Known as “VibroFlotationVibroFlotation“.“. Is used to densify clean, Is used to densify clean,

cohesionless soils.cohesionless soils. The action of the vibrator, The action of the vibrator,

usually accompanied by usually accompanied by water jetting. water jetting.

Allowing them to move into a Allowing them to move into a denser configuration, denser configuration, typically achieving a relative typically achieving a relative density of 70 to 85 percent. density of 70 to 85 percent.

Expected Vibro-Compaction Results:Expected Vibro-Compaction Results:

Ground TypeGround Type Relative EffectivenessRelative Effectiveness

SandsSandsExcellentExcellent

Silty SandsSilty SandsMarginal to GoodMarginal to Good

SiltsSiltsPoorPoor

ClaysClaysNot applicableNot applicable

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

Dynamic CompactionDynamic Compaction Dynamic Compaction is the dropping of heavy Dynamic Compaction is the dropping of heavy

weights on the ground surface to densify soils at weights on the ground surface to densify soils at depth.depth.

Pounder (Tamper)Mass = 10-30 tonsDrop = 50-100 ft

Typical Dynamic Compaction Program Involves:Typical Dynamic Compaction Program Involves: Weights of 10 to 30 tons.Weights of 10 to 30 tons. Drop heights of 50 to 100 ft.Drop heights of 50 to 100 ft. Impact grids of 7 x 7 ft to 20 x 20 ft.Impact grids of 7 x 7 ft to 20 x 20 ft.

Important Dynamic Compaction Geotechnical Parameters:Important Dynamic Compaction Geotechnical Parameters: Soil conditions. Soil conditions. Groundwater level. Groundwater level. Relative density. Relative density. Degree of saturation.Degree of saturation. Permeability.Permeability.

Important Dynamic Compaction Construction Conditions:Important Dynamic Compaction Construction Conditions: Minimum 100-150 ft clearance from any structure. Minimum 100-150 ft clearance from any structure. Review site for vibration sensitivity.Review site for vibration sensitivity.

Dynamic Compaction Acceptance TestingDynamic Compaction Acceptance Testing:: Large-Scale Load Test .Large-Scale Load Test . Standard Penetration Test (SPT). Standard Penetration Test (SPT). Cone Penetrometer Test (CPT). Cone Penetrometer Test (CPT). Pressuremeter Test (PMT). Pressuremeter Test (PMT). Dilatometer Test (DMT).Dilatometer Test (DMT). Shear-Wave Velocity Profile.Shear-Wave Velocity Profile.

BlastingBlasting

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

Expected Soil Behavior with Blasting:Expected Soil Behavior with Blasting: Immediate and long-term surface settlement. Immediate and long-term surface settlement. Settlement can be 2-10 percent of treated strata Settlement can be 2-10 percent of treated strata

thickness. thickness. Penetration resistance will increase slowly with Penetration resistance will increase slowly with

time for several weeks. time for several weeks. Dense zones may be loosened during blasting.Dense zones may be loosened during blasting.

Design Considerations:Design Considerations:

Charges should be placed at approximately 1/2-3/4 of Charges should be placed at approximately 1/2-3/4 of desired depth of compaction. desired depth of compaction.

Spacing of detonation holes should be between 5-15 m. Spacing of detonation holes should be between 5-15 m. Successive coverage's are separated by hours or days. Successive coverage's are separated by hours or days. Individual charge 1-12 kg, the amount of total explosive is Individual charge 1-12 kg, the amount of total explosive is

89-150 g/m^3 of treated soil. 89-150 g/m^3 of treated soil. Soil closest to the surface will be poorly compacted and may Soil closest to the surface will be poorly compacted and may

need compaction by another method or removal. need compaction by another method or removal. The compaction resulting from blasting is a function of the The compaction resulting from blasting is a function of the

initial relative density.initial relative density.

ReferencesReferences

• http://www.concrete-catalog.com/soil_compaction.htmlhttp://www.concrete-catalog.com/soil_compaction.html• http://tc17.poly.edu/vc.htmlhttp://tc17.poly.edu/vc.html• http://www.haywardbaker.com/services/dynamic_compahttp://www.haywardbaker.com/services/dynamic_compa

ction.htmlction.html• http://www.keller-ge.co.ukhttp://www.keller-ge.co.uk• http://www.sbe.napier.ac.uk/projects/compaction/http://www.sbe.napier.ac.uk/projects/compaction/

chapter3a.htmchapter3a.htm• http://www.haywardbaker.com/services/http://www.haywardbaker.com/services/

dynamic_compaction.htmdynamic_compaction.htm• www.geoengineer.org/files/Compaction-Sivakugan.pptwww.geoengineer.org/files/Compaction-Sivakugan.ppt• http://externalweb.nmt.edu/mining/labs.htmhttp://externalweb.nmt.edu/mining/labs.htm