Compaction

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Compaction

Courtesy of U.S. WICK DRAIN, INC.

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1. Soil Improvement

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1.1 Methods for Soil Improvement
Ground Reinforcement
• • • • • • • • • • • Stone Columns Soil Nails Deep Soil Nailing Micropiles (Mini-piles) Jet Grouting Ground Anchors Geosynthetics Fiber Reinforcement Lime Columns Vibro-Concrete Column Mechanically Stabilized Earth • Biotechnical

Ground Improvement
• Deep Dynamic Compaction • Drainage/Surcharge • Electro-osmosis • Compaction grouting • Blasting • Surface Compaction • • • • • •

Ground Treatment
Soil Cement Lime Admixtures Flyash Dewatering Heating/Freezing Vitrification

Compaction
Shaefer, 1997

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1.1 Methods for Soil ImprovementJet Grouting

Courtesy of Menard-soltraitement

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1.1 Methods for Soil ImprovementSoil Nailing

Courtesy of Atlas Copco Rock Drilling Equipment

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2. Compaction

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2.1 Compaction and Objectives
Compaction
• Many types of earth construction, such as dams, retaining walls, highways, and airport, require man-placed soil, or fill. To compact a soil, that is, to place it in a dense state. • The dense state is achieved through the reduction of the air voids in the soil, with little or no reduction in the water content. This process must not be confused with consolidation, in which water is squeezed out under the action of a continuous static load.

Objectives:
(1) Decrease future settlements (2) Increase shear strength (3) Decrease permeability

(From Lambe, 1991; Head, 1992)

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2.2 General Compaction Methods
Coarse-grained soils Laboratory
•Vibrating hammer (BS)

dough

Fine-grained soils
•Falling weight and hammers •Kneading compactors •Static loading and press

•Hand-operated vibration plates •Motorized vibratory rollers

Field

•Rubber-tired equipment •Free-falling weight; dynamic compaction (low frequency vibration, 4~10 Hz)

•Hand-operated tampers •Sheepsfoot rollers •Rubber-tired rollers

Vibration

Kneading
(Holtz and Kovacs, 1981; Head, 1992)

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3. Theory of Compaction (Laboratory Test)

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3.1 Laboratory Compaction
Origin
The fundamentals of compaction of fine-grained soils are relatively new. R.R. Proctor in the early 1930’s was building dams for the old Bureau of Waterworks and Supply in Los Angeles, and he developed the principles of compaction in a series of articles in Engineering News-Record. In his honor, the standard laboratory compaction test which he developed is commonly called the proctor test.

Purpose
The purpose of a laboratory compaction test is to determine the proper amount of mixing water to use when compacting the soil in the field and the resulting degree of denseness which can be expected from compaction at this optimum water

Impact compaction
The proctor test is an impact compaction. A hammer is dropped several times on a soil sample in a mold. The mass of the hammer, height of drop, number of drops, number of layers of soil, and the volume of the mold are specified. 10

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3.1.1 Various Types
Various types of compaction test

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1: your test 2: Standard Proctor test

3: Modified Proctor test
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3.1.2 Test Equipment
Standard Proctor test equipment

Das, 1998

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3.1.3 ComparisonStandard and Modified Proctor Compaction Test Summary of Standard Proctor Compaction Test Specifications (ASTM D-698, AASHTO)

Das, 1998

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3.1.3 ComparisonStandard and Modified Proctor Compaction Test (Cont.) Summary of Modified Proctor Compaction Test Specifications (ASTM D-698, AASHTO)

Das, 1998

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3.1.3 Comparison-Summary
Standard Proctor Test 12 in height of drop 5.5 lb hammer 25 blows/layer 3 layers Mold size: 1/30 ft3 Energy 12,375 ft·lb/ft3 Modified Proctor Test 18 in height of drop 10 lb hammer 25 blows/layer 5 layers Mold size: 1/30 ft3 Energy 56,250 ft·lb/ft3 Higher compacting energy 15

3.1.4 Comparison-Why?
• In the early days of compaction, because construction equipment was...
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