Hayward Baker Grouting

General Grouting Grouting is… the injection of pumpable uid materials into a soil or rock formation to change the physical characteristics of the formation.

Geotechnical Constructi

Grouting Types

Geotechnical Constructi

Grouting Selection Considerati Consideration on 

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Site specic requir requirement ement  Strength  Permeability  Permanence Soil type Soil groutabi groutability lity  Porosity  Gradation  Fines content !erburden stress

Geotechnical Constructi

Grouting Can Prevent…     

Collapse of granular soils Settlement under adjacent foundations Ground"ater Ground "ater mo!ement #tilities damage  $unnel  $ unnel run%ins

Geotechnical Constructi

Grouting Can Provide…    

&ncreased soil strength and rigidity 'educed ground mo!ement Ground"ater control Predictable degree of impro!ement

Geotechnical Constructi

Grouting is Accomplished by…   

(ri!en or drilled grout pipe installation Cased or uncased drilling and installation of SPGP 'ock drilling and packer installation

Geotechnical Constructi

Grouting  Design Steps 1. Identify

Ground Modification needed?

2. Establish objectives of grouting program

Problem understood?

3. Perform special geotechnical study

Soil mass groutable?

4. Develop initial grouting program

Special expertise needed?

. Develop performance prediction

Performance acceptable?

!. "ompare #ith other solutions

Grouting best solution?

underground construction problem

$. %efine design and prepare specifications

Geotechnical Constructi

Ranges of Soils by Grouting Method

Geotechnical Constructi

Grouting Three eys to Grouting Control Grout hole location and geometry &njection parameters Grout properties) liquid* transition* set 

Geotechnical Constructi

Compaction Grouting Compaction Grouting uses displacement to improve ground conditions. & very viscous 'lo#( mobility)* aggregate grout is pumped in stages* forming grout bulbs* #hich displace and densify the surrounding soils. +ignificant improvement can be achieved by se,uencing the grouting #or- from primary to secondary to tertiary locations. Geotechnical Constructi

Compaction Grouting Applications 

+arstic 'egions

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'ubble Fill Poorly Placed Fill ,oosened Soil) Pre%$reatment

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,oosened Soil) Post%$reatment ,iqueable Soils Collapsible Soils  $o compensate for ground loss during tunneling

Geotechnical Constructi

Compaction Grouting Applications

Geotechnical Constructi

Compaction Grouting Process

Geotechnical Constructi

Compaction Grouting Delivery Methods !nstallation of grout pipe" - (rill or dri!e casing - ,ocation !ery important - 'ecord ground information from casing installation !nitiation of grouting" -  $ypically bottom up but can also be top do"n - Grout rheology important lo" mobility* not necessarily lo" slump/ - #sually pressure and0or !olume of grout limited - Slo"* uniform stage injection 1ore2

Geotechnical Constructi

Compaction Grouting Delivery Methods# cont$d Continuation of grouting " - n%site batching can aid control - Grout rheology important - Pressure* grout quantity injection rate* and indication

of hea!e are controlling factors - Sequencing  of of plan injection points !ery important

Geotechnical Constructi

Compaction Grouting Geotechnical Considerations Se!eral conditions must e3ist in order for compaction grouting to yield its best results) 

 $he in situ !ertical stress in the treatment stratum must be su4cient to enable the grout to displace the soil hori5ontally if uncontrolled hea!e of the ground surface occurs densication "ill be minimi5ed/

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 $he grout injection rate should be slo" enough to allo" pore pressure dissipation. Pore pressure dissipation should also be considered in hole spacing and sequencing

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Sequencing of grout injection is also important. &f the soil is not near saturation* compaction grouting can 1ore2 usually be e6ecti!e in most silts and sands Geotechnical Constructi

Compaction Grouting Geotechnical Considerations# cont$d 

Soils that lose strength during remolding saturated* ne% grained soils7 sensiti!e clays/ should be a!oided.

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Greater displacement "ill occur in "eaker soil strata. 83humed grout bulbs conrm that compaction grouting focuses impro!ement "here it is most needed

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Collapsible soils can usually be treated e6ecti!ely "ith the addition of "ater during drilling prior to compaction grout injection

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Stratied soils* particularly thinly stratied soils* can be cause for di4cult or reduced impro!ement capability.

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'ate of tunnel ad!ance and tunneling method in case of compensation grouting/ Geotechnical Constructi

Compaction Grouting Range of !mprovable Soils

Geotechnical Constructi

Compaction Grouting %A&%C Methods 9uality control includes procedural inspection and documentation of the "ork acti!ity* testing to ensure proper mi3 design0injection rates* and !erication of ground impro!ement "here applicable. Ground impro!ement can be assessed by Standard Penetration $esting* Cone Penetrometer $esting* or other similar methods. (ata recording of important grouting parameters has been utili5ed on sensiti!e projects.

Geotechnical Constructi

Compaction Grouting Advantages  Advantages     

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Pinpoint treatment Speed of installation :ide applications range 86ecti!e in a !ariety of soil conditions Can be performed in !ery tight access and lo" headroom conditions ;on%ha5ardous ;o "aste spoil disposal ;o need to connect to footing or column

1ore2

Geotechnical Constructi

Compaction Grouting  Advantages# cont$d 

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;on%destructi!e and adaptable to e3isting foundations 8conomic alternati!e to remo!al and replacement or piling B ft0sec Dm0sec/E.  $his energy breaks do"n the soil matri3 and replaces it "ith a mi3ture of grout slurry and in situ soil soilcrete/. Single uid jet grouting is most e6ecti!e in cohesionless soils.

Geotechnical Constructi

Double (luid 'et Grouting )Soilcrete D* < t"ophase internal uid system is employed for the separate supply of grout and air do"n to di6erent* concentric no55les. $he grout erodes in the same e6ect and for the same purpose as "ith Single Fluid. 8rosion e4ciency is increased by shrouding the grout jet "ith air. Soilcrete columns "ith diameters o!er  ft can be achie!ed in medium to dense soils* and more than > ft in loose soils. $he double uid system is more e6ecti!e in cohesi!e soils than the single uid system. Geotechnical Constructi

Triple (luid 'et Grouting )Soilcrete T* Grout* air and "ater are pumped through di6erent lines to the monitor. Coa3ial air and high%!elocity "ater form the erosion medium. Grout emerges at a lo"er !elocity from separate no55les/ belo" the erosion jets/. $his separates the erosion process from the grouting process and tends to yield a higher quality soilcrete. $riple uid jet grouting is the most e6ecti!e system for cohesi!e soils.

Geotechnical Constructi

Super'et Grouting Grout* air and drilling uid are pumped through separate chambers in the drill string. #pon reaching the design drill depth* jet grouting is initiated "ith high !elocity* coa3ial air and grout slurry to erode and mi3 "ith the soil* "hile the pumping of drilling uid is ceased.  $his system uses opposing no55les and a highly sophisticated jetting monitor specically designed for focus of the injection media. #sing !ery slo" rotation and lift* soilcrete column diameters of =%=> ft %Bm/ can be achie!ed.  $his is the most e6ecti!e system for mass stabili5ation Geotechnical Constructi application or "here surgical treatment is necessary.

 'et Grouting Process

Geotechnical Constructi

Super'et Grouting Process

Geotechnical Constructi

 'et Grouting !mportant Geotechnical and Structural Considerations  Het grouting is e6ecti!e across the "idest range of soil types of any grouting system* including silts and some clays. Iecause it is an erosion based system* soil erodibility plays a major role in predicting geometry* quality and production. Cohesionless soils are typically more erodible than cohesi!e soils. Geotechnical Constructi

 'et Grouting Soil +rodibility Since the geometry and physical properties of the soilcrete are engineered* the degree of impro!ement can be readily predicted.

Geotechnical Constructi

 'et Grouting Typical Soilcrete Strengths Soilcrete strengths are !ariable and di4cult to predict* particularly in layered soils. $his chart represents an estimate of a!erage results e3pected.

Geotechnical Constructi

 'et Grouting Applications  Het grouting o6ers an alternati!e to con!entional grouting* chemical grouting* deep slurry trenching* proprietary underpinning systems* or the use of compressed air or free5ing in tunneling* etc.  Het grouting should be considered in any situation requiring control of underground uids* or e3ca!ation of unstable soil* "hether "ater%bearing or other"ise.

Geotechnical Constructi

 'et Grouting Applications

Geotechnical Constructi

 'et Grouting Design Considerations  Het grouting systems can be designed to mi3 the soil "ith a grout or nearly replace it "ith grout. For underpinning and e3ca!ation support "ith ground"ater control/* the design consists of de!eloping a contiguous soilcrete mass to resist o!erturning and sliding "hile maintaining the integrity of supported structures and nearby utilities. 2more

Geotechnical Constructi

 'et Grouting Design Considerations (esign Considerations for #nderpinning - Iearing capacity of the system - 'etaining system e!aluation for lateral earth pressures and surcharge loads - Settlement re!ie" - Strength adequacy of the system (esign Considerations for 83ca!ation Support - :hat depth is necessary and "hat shear strength and geometry of soilcrete "ill resist the surcharge* soil and "ater pressure imposed after e3ca!ationJ -