Artificial Ground Freezing -

Artificial Ground Freezing -

Artificial Ground Freezing Will Greenwood Clark Green Mike Partenio CEE 542 Contents 1.0 Introduction

2.0 Effects on Soil and Properties 3.0 In the Field 4.0 Advantages and Disadvantages 5.0 Case Study 6.0 Current State (Info from SoilFreeze, Inc.) 7.0 Conclusions 1.0 Introduction 1.1 History

1.2 Concept 1.3 Classification Refrigeration plant (MoreTrench) 1.1 History 1.2 Concept Wagner and Yarmak 2012

Johanssan 2009 1.2 Concept MoreTrench 1.3 Classification ASTM D4083-89

2.0 Effects on Soil Properties 2.1 Hydraulic Conductivity 2.2 Strength and Stiffness 2.3 Volume Change Characteristics 2.4 Laboratory Testing 2.1 Hydraulic Conductivity Frozen ground practically impermeable

Be aware of field limitations Hydraulic conductivity may increase after thawing Concern when freezing into bedrock 2.2 Strength and Stiffness Strength increases

Typical strengths of frozen soils (Klein 2012) Sand: 15 MPa Clay: 3 MPa Frozen sands and frozen clays exhibit similar stress-strain behavior Stiffness increases 2.2 Strength and Stiffness

Da Re et al. 2003 2.3 Volume Change Pore water volume increase of 9% Soil heave Clays may consolidate below freezing front Thaw settlement

2.4 Laboratory Testing Lab testing standards are documented by both ASTM and JGS ASTM D7300-11 Strength of frozen soil samples under constant strain rate

ASTM D5520-11 Creep properties of frozen soil samples by uniaxial compression JGS 0171-2003 Frost heave prediction in soils Thermal properties always tested 2.4 Laboratory Testing Mostly intended for natural ground freezing Standards for triaxial testing of unfrozen soil

do not apply to frozen soil Shear stress, triaxial compression, thaw settlement standards still needed 3.0 In the Field 3.1 Equipment 3.2 Methods for Design

3.3 Freezing Time 3.4 Special Considerations 3.1 Equipment Mobile Freeze Plant Freeze Pipes

Steel HDPE Coolant Typically Calcium Chloride. Commercial coolants.

MoreTrench 3.1 Equipment MoreTrench Wagner and Yarmak 2012 3.2 Methods for Design

Performance approach with contractor. Experience needed. Sanger and

Sayles 1979, Harris 1995 FEM TEMP/W Plaxis Geo-Slope International

McCain et al. 2013 3.3 Freezing Time Jessberger and Vyalov 1978 Sanger and Sayles 1979

3.4 Special Considerations Groundwater velocity (< 2 m/day threshold) Smaller spacing or multiple pipe rows. LN2 Reduce hydraulic conductivity. (Klein 2012). Groundwater salinity

Reduces freezing temperature and strength. Incomplete freezing. 3.4 Special Considerations Temperature monitoring Thermocouples in key locations. Soil heave and creep. Monitor closely be aware of adjacent structures.

4.0 Advantages Soil applicability and versatility Various improvement geometries

Angled freeze pipes Cost-effective

All soil and site conditions Freeze pipe geometry for cross passage construction, Nanjing Metro, China Replaces multiple methods

Ground returns to original state Dayong, Hui (2010) 4.0 Disadvantages Energy intensive Extensive monitoring Possible failures

Uncontrolled frozen ground thickness Damage to AGF equipment, causing leaks Damage to nearby structures 5.0 Case Study Dijk, P. and Bouwmeester-van den Bos, J. (2001)

6.0 Current Conditions Ground freezing is becoming increasingly more common for everyday shoring projects Currently competitive on a cost-basis Typical cost approximately $30 $60 per square foot of frozen soil wall area (SoilFreeze, Inc.) 7.0 Conclusions

Freeze soil pore water with coolant circulation through pipes to: Control groundwater or contaminant mobility Increase strength and stiffness Versatile and technique for ground

improvement Applicable to entire soil range Applicable to various site stratigraphy and conditions Proper site characterization is key

Questions? References

Recently Viewed Presentations

  • Statistics - New York University

    Statistics - New York University

    The Visual Data Do Tell the Story:Napoleon's March to and from Moscow
  • simo n Built by Schools for Schools Staff

    simo n Built by Schools for Schools Staff

    Catholic Ladies College, Eltham. For hosting today's event. ... Choose Rating Scale from the library of rating scales the school has created. Choose the relevant intervals that will be required for when a judgement call is to be made.
  • Welcome to Queen Anne Medical Electrolysis

    Welcome to Queen Anne Medical Electrolysis

    At Queen Anne Medical Electrolysis, we use the "Blend Method," Combining Thermolysis - Alternating Current which destroys the hair follicle by heat, And the Galvanic Method - Direct Current which causes a chemical destruction of the follicle.
  • Genetic diseases - Fakultní nemocnice Hradec Králové

    Genetic diseases - Fakultní nemocnice Hradec Králové

    Genetic diseases traditionally - 3 types of diseases 1. genetically determined 2. environmentally determined 3. 1. + 2. today - distinctions are blurred up to 20% of pediatric in-patients have genetic abnormality about 50% of spontaneous abortuses have chromosomal aberration...
  • Microarray Analysis - National Cancer Institute

    Microarray Analysis - National Cancer Institute

    Microarray Technologies, Sample Processing Methods . Microarray comparisons to RNA-Seq. Data Analysis. Experimental Design. QC methods. Preprocessing: Normalization and low level analysis algorithms. Statistical Analysis. Sources of variation. Common statistical models used for analysis of microarray data. Batch effects and...


    What we did: Chapters 1-5 Why not Chapter 6? → 3-D incompressible flow (sources, doublet, etc.) Chapters 7-9, 11 and 12 Why not Chapter 10? → Fluids II material (nozzles, diffusers, etc.) Multiple examples of applications to flight and projectile...
  • Presentazione di PowerPoint

    Presentazione di PowerPoint

    Appropriatezza. Qualora il cliente scelga di non fornire le informazioni richieste dall'impresa di investimento circa le sue conoscenze ed esperienze, ovvero qualora tali informazioni siano insufficienti, l'impresa di investimento avverte il cliente che la sua decisione impedirà di determinare se...
  • Snímka 1 -

    Snímka 1 -

    Triedy sú pestré s množstvom podnetného materiálu pre hru a rozvoj zručností našich detí. V edukačnom procese využívame moderné učebné pomôcky - Lego Dacta, Logico primo, digitálne hračky a PC s výukovými programami..., rozvíja sa spolupráca s rodinou a organizáciami...