keller 67-03e soilcrete

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The Soilcrete ® – Jet Grouting Process

Brochure - E



Contents

History ................ ................ ...

Soilcrete ® – Jet Grouting Process ..........

Process Variations ...............

Construction Forms ............

Construction Sequences .....

Stabilisation .........................

Sealing .................................. 11

Addresses ................ ............



3

With the aquisition of a licence in for the jet grouting process

and the introduction into Germanyunder the trademark “Soilcrete ®”,Keller Grundbau entered into anew eld of soil stabilization.

Soilcrete ® – History

Small scale underpinning works were thebeginnings of an unusual way of jet grouting.To reach today’s state of the art, additionaldevelopment was necessary.

The process was modied to•

suit different types of soils.

The application was developed•

step by step to provide solutionsto a variety of problems.

Equipment was developed•

and improved.

The Soilcrete• ®

-technique hasbeen enhanced constantly.

This brochure reports on the state ofthe Soilcrete ®-technique today.



5

The Soilcrete ®- propertiesSoilcrete ® acts in the ground according tothe specication either as a stabilization oras a sealing structure. A combination ofboth properties is increasingly required.The compressive strength of Soilcrete ® ranges from to N/mm and isdetermined by the cement content andthe remaining portion of the soil in theSoilcrete ® mass. The sealing effect ofSoilcrete ® against water ingress is achievedby selecting a suitable grout suspension andif necessary by the addition of bentonite.The type and quantity of the injected groutmaterial as well as the kind and volume ofthe remaining soil particles in the Soilcrete ® mass guiding the sealing properties.

Depending on the nature of soils, Soilcrete ®-cut-offs are able to reduce the coefficientof permeability by several decimal powers.High quality requirements in respect ofthe degree of sealing effect necessitateextensive production efforts. For manyapplications both the strengthening andsealing characteristics of the Soilcrete ®-elements are used. The selected suspen-

sions need to be composited accordingly.

Soilcrete®-sealing mixturestested in a laboratory

Soilcrete®-pump andcontrol station

Soilcrete®-cubaturesforming a rm contactwith any kind offoundation forms

. . .

Passing by weight [%]

Grain size [mm Ø] Setting time [days]

Silt Sand

non-cohesivesoil

cohesive soil

Gravel

Compressive strength in % of the nal strength

Compressive strenght of Soilcrete ® Development of Soilcrete ®-strength

Type of soil Silt Sand Gravel

Compressive strength [N/mm ] ≤ ≤ <

Soilcrete ®

Foundation



6

Soilcrete ® is produced in three different ways. The method to be used is determinedaccording to the prevailing soil conditions, the geometrical form and the required qualityof the Soilcrete ®-elements.

Soilcrete ® – Process Variations

Soilcrete ® - S(Single direct process) operates with agrout jet of min. m/sec. exit velocityfor simultaneous cutting and mixingof the soil without an air schroud.The S process is used for small tomedium sized jet grout columns.

Soilcrete ® - D(Double direct process) operates with agrout jet of min. m/sec exit velocityfor simultaneous cutting and mixing of thesoil. To increase the erosion capability andthe range of the grout jet, air shrouding bymeans of shaped air jet nozzle is used.The D process is mainly used for panelwalls, underpinning and sealing slabs.

Soilcrete ® - T(Triple separation process) erodes thesoil with an air shrouded water jet of min.

m/sec exit velocity. Grout is injectedsimultaneously through an additionalnozzle located below the water jet nozzle.The grout pump pressure ranges above

bar. A variation of this process operateswithout air shrouding of the water jet.The T process is used for underpinning

works, cut off walls and sealing slabs and ismainly used for the treatment of cohesivesoils.

The triple Soilcrete®-rodsprovide separate owsof air, water and groutto the jet nozzle holder

Drill/core bit withthe above-installedSoilcrete®-monitor.

GroutAir Backow

Air shroudedgrout jet

WaterAir Backow

Air shroudedwater jet

Grout

Grout jet

Grout Backow

Grout jet

Computer designand optimisation ofcomplicated Soilcrete®-elements by Keller‘sown software Soiljet ®



7

The basic geometrical form of Soilcrete ®-elements is created through movementsof the drill rods:

Pulling of the drill rods without•

rotation resulting in panels –if several jet nozzles are usedmultiple panels may be produced.

Pulling and swivelling•

create segments.

Pulling and rotating create•

complete columns.

Soilcrete ® – Construction Forms

Exposed test eld with several Soilcrete®-disksfor a sealing slab

Panel wall with sealing slab Underpinning elements

Sealing slabs

Panel walls

Box walls

Column walls

Deep foundation

Exposed Soilcrete®-elements of an underpinningwall in sandy soils

Soilcrete ® – basic formsThe Soilcrete ® basic forms may be arrangedand combined in any way to form each typeof element.

Interlinked Soilcrete ®-elements

Interlinked bodies –constructed from uniform

elements

Column

One sided

Twin sided

Lamella

A = Quarter ColumnB = Half ColumnC = Complete Column



8

Soilcrete ® – Construction Sequenses

Soilcrete ®-site installations consist of storagecontainers, silos and a compact mixing andpumping unit. Several high pressure hoseconnections and control cable lines connectthe pumping unit with the Soilcrete ® drillingrig at the installation point. The mast lengthof the rig varies from . m in cellars or shaftsand up to . m in open areas. The borepoints are normally located in small trenchesequipped with sludge pumps. From there theexcess material, water-cement-soil mixture ispumped to setting ponds or tanks.

Small drilling rigsmanufactured by Kellerprovide access toconned working places

Drilling

Drill rods equipped with jetnozzle holder and drill bit areused to drill the jet grouting holedown to the required depth.Normally the jet grout mixture isused as drill ushing to stabilizethe borehole during the drillingoperation. In masonry and

concrete, special drilling bits areused.

Jetting

The disolution of the graintexture with a powerful uid jetstarts at the lower end of theSoilcrete ®-element. The excesswater soil cement mixture isremoved to the surface throughthe annular space between drillrod and bore-hole wall. The pre-

selected production parametersare constantly monitored.

Grouting

For all Soilcrete ®-variationscement suspension is injectedunder pressure simultaneouslywith the erosion of the soil. Theturbulences caused by the jettingtechnique results in the uniformmixing of the grout with thesoil within the treatment zone.

Until the grout in the Soilcrete®

-elements starts setting hydro-static pressure in the boreholeis kept by backlling grout intothe hole from time to time.

Grout suspension

Pump

Storage tank

WaterAir

Backow recycling



9

Optical and manual checking as well as con-trols and tests according to the requirementslaid down in the European standard EN ensure quality work manship. Extension

Soilcrete ®-elements of each formmay be constructed fresh onfresh as well as fresh against rmand combined and connected ina variety of ways. The workingsequence follows the technicalrequirements and the conditionsof the structure to be treated.

Recording unit M

Important constructionparameters may beelectronically recorded

Core recovery fromSoilcrete®-elements

Time

[sec]

Process: Soilcrete-D- Process (1.0.0)Inventar: 130481 Site: 6814225Lot: 0 Point: 19 Ref. No.: 3Date: 12.06.10 Time: 16:287:30 Interval: 2 secWeight:Legend:

Flow

[l/min]

Groutpressure

[bar]

Drillingpressure

[bar]

Depth

[m]

Revolutions

[rpm]

Progress

[m/min]

Total time: 149.63 min Max. depth: 6.3 m Length column: 6.1 m

Process monitoringUp to different parameters for theconstruction of Soilcrete ®-elements maybe recorded and used by the engineer-in-charge of supervision and control.

Cement/Bentonite

Mixer



11

Soilcrete ® for sealingBuilding pit walls constructed of deformation and ground water resistant Soilcrete ®-underpinning elements, combined with low permeable Soilcrete ®-slabs enablesthe execution of deep building pits without the need for large scale ground waterlowering. Environmental safe mineral binder materials are used for Soilcrete ®.

Soilcrete ®-panel wallsto cut off groundwater are used belowroads and buildings, forcrossing pipelines and tosubdivide building pitsinto different excavationsections. According to

the sealing requirements single or multiple panels maybe constructed.

For small building pitsand shafts with reducedwidth Soilcrete ®-slabsare used as preventionagainst the water upliftpressure, reducing therequired depth of slabsnormally required to re-sist the hydrostatic uplift.

Panel walls Vault slabs

Column walls Sealing cover

Dam sealing Joint sealing

Sealing slabs Groundwater exits

In the event of highermechanical strain byshearforce, danger ofundermining or of a

high impermeabilityrequirements, cut offwalls of intersectingSoilcrete ®-columnsmay be constructed.

The Soilcrete ®-coverprotects the groundwaterbelow buildings againstaffects from construction

activities and old toxicwaste de-posits.

Soilcrete ® may be usedto repair dam cores orenlarge cut-off walls inor below dams.

For sealing of joints be-tween piles, sheet pilesor other constructionparts in the ground theSoilcrete ®-wing-jet isapplied.

Soilcrete ®-sealing slabsare constructed by meansof overlapping columnswithin an uplift proofdepth. The sealing slabs

may be connected to anykind of vertical sealingsystems.

Sealing walls are oftenused as temporaryground water barriers.The reinstatement ofthe permeability may

be reached using theSoilcrete ®-process towash out the bindermaterial from prede ter-mined sections.



Keller Holding GmbHKaiserleistraße 863067 OffenbachGermany

Tel. +49 69 8051-0E-mail: [email protected]

www.KellerHolding.com

A company of Keller Group plc

keller 67-03e soilcrete

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