Foreword
This document (EN 14679:2005) has been prepared by Technical Committee CEN/TC 288 “Execution of special geotechnical works”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2005, and conflicting national standards shall be withdrawn at the latest by October 2005.
The document has been prepared to stand alongside EN 1997-1 and prEN 1997-2. This document expands on design only where necessary, but provides full coverage of the construction and supervision requirements.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
1 Scope
This document specifies general principles for the execution, testing, supervision and monitoring of deep mixing works carried out by two different methods: dry mixing and wet mixing.
Deep mixing considered in this document is limited to methods, which involve:
- a) mixing by rotating mechanical mixing tools (see Annex A, Figure A.1) where the lateral support provided to the surrounding soil is not removed;
- b) treatment of the soil to a minimum depth of 3 m;
- c) different shapes and configurations, consisting of either single columns, panels, grids, blocks, walls or any combination of more than one single column, overlapping or not (see Annex A, Figures A.8, A.9, A10, A11 and A.12);
- d) treatment of natural soil, fill, waste deposits and slurries, etc.
Other ground improvement methods using similar techniques exist (see A.3.5). 
Guidance on practical aspects of deep mixing, such as execution procedures and equipment, is given in Annex A. Main applications are exemplified in Annex A, Figure A.14. Methods of testing, specification and assessment of design parameters, which are affected by execution, are presented in Annex B.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 196-1, Methods of testing cement — Part 1: Determination of strength
EN 196-2, Methods of testing cement — Part 2: Chemical analysis of cement
EN 196-3, Methods of testing cement — Part 3: Determination of setting time and soundness
EN 196-4, Methods of testing cement — Part 4: Quality determination of constituents
EN 196-5, Methods of testing cement — Part 5: Pozzolanicity tests for pozzolanic cement
EN 196-6, Methods of testing cement — Part 6: Determination of fineness
EN 196-7, Methods of testing cement — Part 7: Methods of taking and preparing samples of cement
EN 196-8, Methods of testing cement — Part 8: Heat of hydration — Solution method
EN 196-21, Methods of testing cement — Part 21: Determination of the chloride, carbon dioxide and alkali content of cement
EN 197-1:2000, Cement — Part 1: Composition, specification and conformity criteria for common cements
EN 197-2:2000, Cement — Part 2: Conformity evaluation
EN 451, Methods of testing fly ash
EN 459-1, Building lime — Part 1: Definitions, specifications and conformity criteria
EN 459-2, Building lime — Part 2: Test methods
EN 791:1995, Drill rigs — Safety
EN 1997-1, Eurocode 7: Geotechnical design — Part 1: General rules
prEN 1997-2, Eurocode 7 — Geotechnical design — Part 2: Ground investigation and testing
EN 12716, Execution of special geotechnical works — Jet grouting
ENV 1991, Eurocode 1: Actions on structures
ENV 10080, Steel for reinforcement of concrete, weldable ribbed reinforcing steel B 500 — Technical delivery conditions for bars, coils and welded fabric
EN ISO 14688-1, Geotechnical investigation and testing — Identification and classification of soil — Part 1: Identification and description (ISO 14688-1:2002)
EN ISO 14688-2, Geotechnical investigation and testing — Identification and classification of soil — Part 2: Principles for a classification (ISO 14688-2:2004)
EN ISO 14689-1, Geotechnical investigation and testing — Identification and classification of rock — Part 1: Identification and description (ISO 14689-1:2003).
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
admixture
fr: additif, addition
de: Zusatzmittel
dispersant, fluidifier, retarding agent
3.2
binder
fr: liant
de: Bindemittel
chemically reactive materials (lime, cement, gypsum, blast furnace slag, fly ash, etc.)
3.3
binder content
fr: dosage en liant
de: Bindemittelgehalt
weight of dry binder introduced per unit volume of soil to be treated
3.4
binder factor
fr: teneur en liant
de: Bindemittelfaktor
ratio of the weight of dry binder introduced to the dry weight of the soil to be treated
3.5
blade rotation number
fr: indice de malaxage
de: Flügelumdrehungszahl
total number of mixing blade rotations per m of shaft movement.
3.6
column
fr: colonne
de: Säule
pillar of treated soil manufactured in situ by a single installation process using a mixing tool. The mixing tool and the execution process govern the shape and size of the cross section of a column
3.7
dry mixing
fr: malaxage par voie sèche
de: Trockenmischverfahren
process consisting of mechanical disaggregation of the soil in situ and its mixing with binders with or without fillers and admixtures in dry powder form
3.8
filler
fr: fines inerte, charge inerte
de: Füller
non-reacting material (sand, limestone powder etc.)
3.9
mixing energy
fr: energie de malaxage
de: Mischungsenergie
resources used for operating machinery
3.10
mixing process
fr: procédé de malaxage
de: Mischvorgang
involves mechanical disaggregation of the soil structure, dispersion of binders and fillers in the soil
3.11
mixing tool
fr: outil de malaxage
de: Mischwerkzeug
tool used to disaggregate the soil, distribute and mix the binder with the soil, consisting of one or several rotating units equipped with several blades, arms, paddles with/without continuous or discontinuous flight augers (see Annex A)
3.12
penetration (downstroke)
fr: descente (de l’outillage)
de: Abbohrvorgang
stage/phase of mixing process cycle, in which the mixing tool is delivered to the appropriate depth and initial
mixing and fluidisation of the soil take place
3.13
penetration or retrieval speed
fr: vitesse de descente ou de remontée
de: Abbohr- bzw. Ziehgeschwindigkeit
vertical movement per unit time of the mixing tool during penetration or retrieval
3.14
penetration or retrieval rate
fr: vitesse de descente ou de remontée par tour
de: Abbohr- bzw. Ziehrate
vertical movement of the mixing tool per revolution of the rotating unit(s) during penetration or retrieval
3.15
retrieval (upstroke)
fr: remontée (montée de l’outillage)
de: Ziehvorgang
stage/phase of mixing process cycle, in which the final mixing and retrieval of the mixing tool take place
3.16
restroke
fr: re-malaxage
de: wiederholter Mischvorgang
restroke is an additional penetration and retrieval cycle of the mixing tool to increase the binder content and/or the column homogeneity
3.17
rotation speed
fr: vitesse de rotation
de: Umdrehungsgeschwindigkeit
number of revolutions of the rotating unit(s) of the mixing tool per unit time
3.18
stroke
fr: malaxage
de: Mischvorgang
one complete cycle of the mixing process
3.19
volume ratio
fr: teneur volumique en coulis
de: Volumenverhältnis
ratio of the volume of slurry injected (in wet mixing) to the volume of soil to be treated
3.20
water/binder ratio
fr: rapport eau/liant
de: Wasser-/Bindemittel-Verhältnis
weight of water added to the dry binder divided by the weight of the dry binder
3.21
wet mixing
fr: malaxage par voie humide
de: Nassmischverfahren
process consisting of mechanical disaggregation of the soil in situ and its mixing with a slurry consisting of water, binders with or without fillers and admixtures
