SIST EN 14199:2005
(Main)Execution of special geotechnical works - Micropiles
Execution of special geotechnical works - Micropiles
1.1 This Standard establishes general principles for the execution of micropiles.
They are for:
- drilled micropiles a shaft diameter not greater than 300 mm;
- driven micropiles a shaft diameter or a maximum shaft cross sectional extension not greater than 150 mm.
1.2 Micropiles are structural members to transfer actions to the ground and may contain bearing elements to transfer directly or indirectly loads and or to limit deformations. Their shaft and base resistance may be improved (mostly by grouting) and they may be constructed with (see Figure 1):
- uniform cross section (straight shaft); or
- telescopically changing shaft dimensions;
- shaft enlargements; and/or
- base enlargement.
1.3 Other than practical considerations, there are no limitations regarding, length, rake (definition of rake, see Figure 2), slenderness ratio or shaft and base enlargements.
1.4 The provisions of the Standard apply to (see Figure 3):
- single micropiles;
- micropile groups;
- reticulated micropiles;
- micropile walls.
1.5 The micropiles which are the subject of this Standard can be installed into the ground using drilling, driving or a combination of these methods.
1.6 The material of micropiles covered by this Standard can be:
- steel or other reinforcement materials;
- grout, mortar or concrete;
- a combination of above.
1.7 Micropiles may be used for:
- working under restricted access and/or headroom conditions;
- foundations of new structures (particularly in very heterogeneous soil or rock formations);
- reinforcing or strengthening of existing structures to increase the capacity to transfer load to depth with acceptable load settlement characteristics, e.g. underpinning works;
- reducing settlements and/or displacements;
- forming a retaining wall;
- reinforcing of soil to form a bearing and/or retaining structure;
- improving slope stability;
- securing against uplift;
- other applications where micropile techniques are appropriate.
1.8 Mixed-
Ausführung von besonderen geotechnischen Arbeiten (Spezialtiefbau) - Pfähle mit kleinen Durchmessern (Mikropfähle)
1.1 Dieses Dokument gilt für die Herstellung
- von gebohrten Mikropfählen mit Schaftdurchmessern kleiner als 300 mm und
- von eingebrachten Mikropfählen mit Schaftdurchmessern bzw. Querschnittsbreiten kleiner als 150 mm.
1.2 Mikropfähle sind Tragglieder, mit deren Hilfe Kräfte in den Baugrund eingeleitet werden. Sie können Tragglieder beinhalten, um direkte oder indirekte Lasten abzuführen bzw. um Verformungen zu begrenzen. Mantel- und Fußwiderstand von Mikropfählen können z.B. durch Verpressung erhöht werden. Bei der Herstellung kann auf verschiedene Konstruktionsformen zurückgegriffen werden (siehe Bild 1):
- einheitlicher Querschnitt (zylindrische Form); oder
- teleskopartige Querschnittsänderung;
- Mantelaufweitungen; und/oder
- Fußaufweitung.
1.3 Es bestehen keine Beschränkungen hinsichtlich Länge, Neigung (Definition siehe Bild 2), Schlankheitsgrad oder Fuß- bzw. Mantelaufweitungen außer den herstellungsbedingten Vorgaben.
1.4 Die Bestimmungen in diesem Dokument gelten für (siehe Bild 3):
- einzelne Mikropfähle;
- Gruppen von Mikropfählen;
- netzartig angelegte Mikropfähle;
- Mikropfahlwände.
Exécution de travaux géotechniques spéciaux - Micropieux
1.1 Ce document établit les principes généraux pour l'exécution des micropieux.
Il s'applique :
- aux micropieux forés dont le diametre du fut est inférieur a 300 mm et ;
- aux micropieux foncés dont le diametre du fut ou la dimension maximale de la section transversale du fut est inférieur a 150 mm.
1.2 Les micropieux sont des structures destinées a transférer des actions au terrain. Ils peuvent contenir des éléments porteurs pour transférer directement ou non les charges et/ou pour limiter leurs déformations. Leur résistance par frottement sur le fut et leur résistance de pointe peuvent etre améliorées (en général par injection) et ils peuvent etre réalisés avec (voir Figure 1) :
- un fut de section transversale uniforme (fut rectiligne) ; ou
- un fut avec des sections transversales variables ;
- des élargissements du fut ; et/ou
- un élargissement de la base.
1.3 En dehors de considérations d'ordre pratique, il n'y a pas de limitation concernant les élargissements du fut ou de la base, la longueur, l'inclinaison ou l'élancement des micropieux (voir Figure 2 pour la définition de l'inclinaison).
1.4 Les dispositions de ce document s'appliquent (voir Figure 3) :
- aux micropieux isolés ;
- aux groupes de micropieux ;
- aux réseaux de micropieux ;
- aux parois de micropieux.
Izvedba posebnih geotehničnih del – Mikropiloti
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Execution of special geotechnical works - MicropilesExécution de travaux géotechniques spéciaux - MicropieuxAusführung von besonderen geotechnischen Arbeiten (Spezialtiefbau) - Pfähle mit kleinen Durchmessern (Mikropfähle)93.020Zemeljska dela. Izkopavanja. Gradnja temeljev. Dela pod zemljoEarthworks. Excavations. Foundation construction. Underground worksICS:SIST EN 14199:2005enTa slovenski standard je istoveten z:EN 14199:200501-maj-2005SIST EN 14199:2005SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14199March 2005ICS 93.020English versionExecution of special geotechnical works - MicropilesExécution de travaux géotechniques spéciaux - MicropieuxAusführung von besonderen geotechnischen Arbeiten(Spezialtiefbau) - Pfähle mit kleinen Durchmessern(Mikropfähle)This European Standard was approved by CEN on 27 October 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of 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.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2005 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14199:2005: E
EN 14199:2005 (E) 2 Contents Page Foreword.4 1 Scope.5 2 Normative references.6 3 Terms and definitions.7 4 Information needed for the execution of the works.11 4.1 General.11 4.2 Special features for micropiles:.11 4.3 List of activities.12 5 Geotechnical investigation.12 5.1 General.12 5.2 Specific requirements.13 6 Materials and products.14 6.1 General.14 6.2 Reinforcement and load bearing elements.14 6.2.1 Steel for reinforcement cage elements.14 6.2.2 Steel for load bearing elements.14 6.2.3 Other materials for reinforcement and load bearing elements.14 6.3 Materials for grout, mortar and concrete.14 6.3.1 Cement.14 6.3.2 Aggregates.15 6.3.3 Water.15 6.3.4 Additions and admixtures.15 6.4 Cement grout.15 6.4.8 Quality control.16 6.5 Mortar and Concrete.16 6.5.1 Mortar and concrete in situ.16 6.5.2 Other concrete.17 6.6 Spacers, centralizers and other components.17 6.7 Coatings and corrosion protection compounds.17 7 Considerations related to design.17 7.1 General.17 7.2 Geometrical construction tolerances.18 7.3 Installation.18 7.4 Reinforcement.19 7.5 Connecting elements.19 7.6 Corrosion protection of steel elements.19 7.7 Spacers and centralizers.20 7.8 Micropile enlargement.20 7.9 Connections to the superstructure.21 7.10 Spacing of micropiles.21 7.11 Special requirements for micropiles installed through very weak soils.21 7.12 Micropile shoe.21 8 Execution.21 8.1 General.21 8.2 Site preparation.22 8.3 Sequence of installation.22
EN 14199:2005 (E) 3 8.4 Drilling.22 8.4.1 General.22 8.4.2 Use of flushing.23 8.4.3 Boreholes supported by casings.24 8.4.4 Drilling with continuous flight augers.24 8.5 Driving.24 8.6 Enlargements.24 8.7 Reinforcement and load bearing elements.25 8.7.1 Handling and storing.25 8.7.2 Joints.25 8.7.3 Spacers and centralizers.25 8.7.4 Installation.25 8.8 Grouting.26 8.8.1 General.26 8.8.2 Grout preparation.26 8.8.3 Borehole testing and pregrouting.27 8.8.4 Filling the borehole with grout.27 8.8.5 Single step grouting through a temporary casing.27 8.8.6 Single step grouting through a load bearing element.27 8.8.7 Grouting and filling during driving.28 8.8.8 Grouting during drilling.28 8.8.9 Multi-stage grouting.28 8.9 Concreting.28 8.10 Trimming of micropiles.28 9 Supervision, testing and monitoring.29 9.1 Supervision.29 9.2 Monitoring of micropile construction.29 9.3 Micropile testing.29 9.3.1 General.29 9.3.2 Static load tests.30 9.3.3 Dynamic load tests and integrity tests.31 10 Records.31 10.1 General.31 10.2 Records for the execution of construction micropiles.31 10.3 Records for micropile tests.33 11 Special requirements.34 Annex A (informative)
Execution methods of micropiles.40 A.1 Drilled micropiles.40 A.2 Displacement micropiles.41 Annex B (informative)
Guidance on geometrical construction tolerances.42 Annex C (informative)
Minimum cover (in mm) for reinforcement and bearing element of low strength steel for cast in place micropiles taking into account exposure classes related to environmental actions as defined in EN 206-1.43 Annex D (informative)
Guidance on corrosion rates.44 Annex E (informative)
Borehole testing and pregrouting.45 Annex F (informative)
Guideline for the preparation of a record for several drilled micropiles.46 Annex G (informative)
Guideline for the preparation of a record for several driven micropiles.47 Bibliography.48
EN 14199:2005 (E) 4 Foreword This document (EN 14199:2005) 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 September 2005, and conflicting national standards shall be withdrawn at the latest by September 2005. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. The general scope of CEN/TC 288 is the standardisation of the execution procedures for geotechnical works, including testing and control methods, and the required material properties. WG 8 has been charged with the subject area of micropiles. The document has been prepared to stand along side EN 1997-1. Clause 7 of this Standard covers design aspects of micropiles. It has been drafted by a working group comprising delegates from 14 countries and is based on the review of national and international codes of practice. 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 the United Kingdom.
EN 14199:2005 (E) 5 1 Scope 1.1 This document establishes general principles for the execution of micropiles. They are for: drilled micropiles a shaft diameter not greater than 300 mm; driven micropiles a shaft diameter or a maximum shaft cross sectional extension not greater than 150 mm. 1.2 Micropiles are structural members to transfer actions to the ground and may contain bearing elements to transfer directly or indirectly loads and or to limit deformations. Their shaft and base resistance may be improved (mostly by grouting) and they may be constructed with (see Figure 1): uniform cross section (straight shaft); or telescopically changing shaft dimensions; shaft enlargements; and/or base enlargement. 1.3 Other than practical considerations, there are no limitations regarding, length, rake (definition of rake, see Figure 2), slenderness ratio or shaft and base enlargements. 1.4 The provisions of the document apply to (see Figure 3): single micropiles; micropile groups; reticulated micropiles; micropile walls. 1.5 The micropiles which are the subject of this document can be installed into the ground using drilling, driving or a combination of these methods. 1.6 The material of micropiles covered by this document can be: steel or other reinforcement materials; grout, mortar or concrete; a combination of above. 1.7 Micropiles may be used for: working under restricted access and/or headroom conditions; foundations of new structures (particularly in very heterogeneous soil or rock formations); reinforcing or strengthening of existing structures to increase the capacity to transfer load to depth with acceptable load settlement characteristics, e.g. underpinning works; reducing settlements and/or displacements;
EN 14199:2005 (E) 6 forming a retaining wall; reinforcing of soil to form a bearing and/or retaining structure; improving slope stability; securing against uplift; other applications where micropile techniques are appropriate. 1.8 Mixed-in-place columns and timber piles are not included in this document. Columns constructed by jet grouting are covered by EN 12716. Ground anchors are covered by EN 1537.
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 197-1, Cement - Part 1: Composition, specifications and conformity criteria for common cements. EN 206-1:
Concrete - Part 1: Specification, performance, production and conformity. EN 791, Drill rigs – Safety. EN 934-2, Admixtures for concrete, mortar and grout - Part 2: Concrete admixtures - Definitions, requirements, conformity, marking and labelling. EN 996, Piling equipment – Safety requirements. EN 1008, Mixing water for concrete - Specification for sampling, testing and assessing the suitability of water, including water recovered from processes in the concrete industry, as mixing water for concrete EN 1536:1999, Execution of special geotechnical work - Bored piles. EN 1537:1999, Execution of special geotechnical work - Ground anchors. EN 1991-1, Eurocode 1: Basis of design and actions on structures – Part 1: Basis of design. EN 1992-1-1, Eurocode 2: Design of concrete structures - Part 1: General rules and rules for buildings EN 1993-1-1, Eurocode 3: Design of steel structures - Part 1-1: General rules and rules for buildings EN 1993-5, Eurocode 3: Design of steel structures – Part 5: Piling. EN 1994-1-1, Eurocode 4: Design of composite steel and concrete structures - Part 1-1: General rules for buildings. EN 1997-1:2004, Eurocode 7: Geotechnical design – Part 1: General rules. EN 10025, Hot-rolled products of non-alloy structural steels. EN 10080, Steel for the reinforcement of concrete weldable ribbed reinforcing steel B 500 - Technical delivery conditions for bars, coils and welded fabric prEN 10138-4, Prestressing steels - Part 4: Bars.
EN 14199:2005 (E) 7 EN 10210, Hot finished structural hollow sections of non-alloy and fine grain structural steels. EN 12699:2000, Execution of special geotechnical works - Displacement piles. EN 12794, Precast concrete foundation piles. EN ISO 11960, Petroleum and natural gas industries - Steel pipes for use as casing or tubing for wells (ISO 11960:2004) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 micropile fr: micropieu de: Mikropfahl piles which have a small diameter (smaller than 300 mm shaft diameter for drilled piles and not greater than 150 mm shaft diameter or maximum shaft cross sectional extension for driven piles) 3.2 enlarged base fr: base élargie de: Fussaufweitung base of the micropile formed to have a cross section greater than that of its shaft 3.3 shaft diameter fr: diamètre du fût de: Pfahldurchmesser diameter of the part of the micropile between the head and the base: a) for micropiles constructed with casing: equal to the external diameter of the casing; b) for micropiles constructed without casing: equal to the maximum diameter of the drilling tool, the maximal cross sectional extension of the driving tool; c) for prefabricated micropiles: equal to the external diameter or cross sectional extension. 3.4 preliminary micropile fr: micropieu préliminaire de: Vorversuchs-Mikropfahl (Probepfahl 1) micropile installed before the commencement of the main piling works or section of the works for the purpose of establishing the suitability of the chosen type of micropile and/or for confirming the design, dimensions and bearing capacity 3.5 trial micropile fr: micropieu de faisabilité de: Eignungsversuchs-Mikropfahl (Probepfahl 2) micropile installed to assess the practicability and suitability of the construction method for a particular application
EN 14199:2005 (E) 8 3.6 test micropile fr: micropieu d’essai de: Abnahmeversuchs-Mikropfahl (Probepfahl 3) micropile to which a load is applied to determine the resistance and deformation characteristics of the micropile and the surrounding ground 3.7 working micropile fr: pieu de fondation de: Bauwerksmikropfahl micropile which is part of a structure 3.8 integrity test fr: essai d’ intégrité de: Integritätsprüfung test carried out on an installed micropile for the verification of soundness of micropile components 3.9 static load test fr: essai de chargement statique de: statische Probebelastung loading test where a micropile is subjected to chosen axial and/or lateral forces at the micropile head for the analysis of its capacity and deformation characteristics 3.10 maintained load test (ML test) fr:essai de chargement par palier de: lastgesteuerte Probebelastung static loading test in which a test micropile has loads applied in incremental stages, each of which is held constant for a certain period or until micropile motion has virtually ceased or has reached a prescribed limit 3.11 constant rate of penetration test (CRP test) fr:essai de chargement à vitesse d’ enfoncement constante de: weggesteuerte Probebelastung static load test in which a test micropile is forced into the ground at a constant rate and the force is measured 3.12 dynamic load test fr: essai de chargement dynamique de: dynamische Probebelastung loading test where a dynamic force is applied on the micropile for analysis of micropile bearing capacity and deformation characteristics 3.13 grout fr: coulis de: Zementmörtel a setting material, usually cement and water, containing sometimes additives or a limited amount of fine aggregates, which transfers load from the bearing element or the micropile shaft to the ground and/or contributes to corrosion protection 3.14 mortar fr: mortier de: Verpressmörtel/Feinkornbeton concrete with very small aggregates (< 8 mm)
EN 14199:2005 (E) 9 3.15 driving fr: fonçage de: Einbringen/Eintrieben method to bring the micropile into the ground to the required depth, such as hammering, vibrating, pressing, screwing or by a combination of these or other methods 3.16 drilling fr: forage de: Bohren method of removing the soil or rock in an intermittent or continuous process 3.17 casing fr: tubage de: Verrohrung tube used to support the micropile hole during the construction of a micropile. The casing can be permanent or temporary. Permanent casing may act as a load bearing element and/or as a corrosion protection 3.18 liner fr: gaine, chemise de: Hülse, Mantelrohr a tube, generally of thin steel sheet or plastic, forming at least part of the shaft of a micropile, e.g. used for the protection of micropile shafts in soft or aggressive grounds or to reduce negative skin friction 3.19 drive tube fr: tube de fonçage de: Vortreibrohr / Rammrohr steel tube used to displace the ground during the formation of a driven cast in place micropile. The drive tube is withdrawn during grouting or concreting 3.20 micropile joint fr: assemblage, connexion de micropieu de: Verbindung means of joining lengths of bearing elements either by welding or by mechanical joints 3.21 coupler fr: manchon de: Koppelelement / Muffe an external device for joining lengths of bar or tube which comprise reinforcement or bearing element 3.22 nipple fr: mamelon de: Nippel an internal device for joining lengths of tubes which comprise reinforcement or bearing element 3.23 centralizer fr: centreur de: Zentrierer device to locate reinforcement centrally in a borehole or casing
EN 14199:2005 (E) 10 3.24 spacer fr: écarteur de: Abstandhalter device to ensure the required grout, mortar or concrete cover or the distance between reinforcing elements 3.25 load bearing element fr: élément porteur de: Tragglied element of steel or other material that is capable of transmitting the load from the structure to the ground 3.26 drilling fluid/mud fr: fluide de forage, boue de forage de: Spülflüssigkeit, Bohrspülung water or a suspension of bentonite, polymers or clay, in water with or without cement and other additions, for stabilization of borehole walls and for flushing 3.27 tube-à-manchettes fr: tube à manchettes de: Manschettenrohr a regularly slotted sleeved tube through that grout injections are possible using a packer device 3.28 working level fr: niveau de travail de: Arbeitsebene level of the platform on which the piling rig works 3.29 clients technical representative fr: representant technique du client de: Technischer Bauherrnvertreter represents the client and is fully acquainted with all aspects of the works related to the use of micropiles including specialist knowledge of mocropile technology 3.30 grouting fr: injection sous pression de: Verpressen pumping of grout or concrete into the borehole with a pressure which is higher than the hydrostatic pressure 3.31 multi-stage grouting fr: injection sous pression repetée de: Nachverpressen high pressure grouting through a tube-à-manchettes, special valves or post-grouting tubes after the grout previously placed in the borehole has set 3.32 filling fr: remplissage gravitaire de: Verfüllen grouting under no applied fluid pressure other than the height of grout fluid. Sometimes referred to as gravity grouting or as tremie grouting
EN 14199:2005 (E) 11 4 Information needed for the execution of the works 4.1 General 4.1.1 Prior to the execution of the work, all necessary information and site investigation data shall be available. 4.1.2 This information should include: a) any legal or statutory restrictions; b) the location of main grid lines for setting out; c) the conditions of structures, roads, services, e
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