EN 15237-2007 en Execution of special geotechnical works - Vertical drainage《特殊土工工程的施工 垂直排水》.pdf

1、BRITISH STANDARDBS EN 15237:2007Execution of special geotechnical works Vertical drainageThe European Standard EN 15237:2007 has the status of a British StandardICS 93.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g

2、40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 15237:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 March 2007 BSI 2007ISBN 978 0 580 50456 3National forewordThis British Standard was published by BSI. It

3、 is the UK implementation of EN 15237:2007.The UK participation in its preparation was entrusted to Technical Committee B/526, Geotechnics.A list of organizations represented on B/526 can be obtained on request to its secretary.This publication does not purport to include all the necessary provision

4、s of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15237February 2007ICS 93.020English VersionE

5、xecution of special geotechnical works - Vertical drainageExcution des travaux gotechniques spciaux - DrainsverticauxAusfhrung von besonderen geotechnischen Arbeiten(Spezialtiefbau) - VertikaldrnsThis European Standard was approved by CEN on 7 January 2007.CEN members are bound to comply with the CE

6、N/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 CEN Management Centre or to

7、 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 CEN Management Centre has the same status as theofficial versions.

8、CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sw

9、eden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Re

10、f. No. EN 15237:2007: EEN 15237:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .5 4 Information needed for the execution of the work.7 5 Geotechnical investigations.8 5.1 General8 5.2 Specific requirements .8 6 Materials and product .9 6.1 General9 6.2

11、Raw materials of prefabricated drains 9 6.3 Band drains 9 6.4 Prefabricated cylindrical drain .13 6.5 Sand drains 15 7 Considerations related to design.15 7.1 Field trials .15 8 Execution15 8.1 Method statement 15 8.2 Preparation of the site.16 8.3 Drain installation16 8.4 Special aspects17 9 Superv

12、ision and monitoring.17 9.1 Supervision 17 9.2 Monitoring 18 10 Records.18 10.1 Records during construction .18 10.2 Records at the completion of the work .18 11 Special requirements 19 11.1 General19 11.2 Safety 19 11.3 Environmental protection .19 11.4 Impact on adjacent structures19 Annex A (info

13、rmative) Practical aspects of vertical drainage 20 Annex B (informative) Aspects of design .41 Annex C (informative) Degree of obligation of the specifications .52 Bibliography 54 EN 15237:2007 (E) 3 Foreword This document (EN 15237:2007) has been prepared by Technical Committee CEN/TC 288 “Executio

14、n 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 August 2007, and conflicting national standards shall be withdrawn at t

15、he latest by August 2007. The document has been prepared to stand alongside EN 19971, Eurocode 7: Geotechnical design Part 1: General rules, and EN 19972 Eurocode 7: Geotechnical design Part 2: Ground investigation and testing. This standard expands on design only where necessary, but provides full

16、coverage of the construction and supervision requirements. This document was drafted by a working group comprising delegates from 10 European countries. Experts from Japan have taken part in the meetings of the working group and contributed to the formulation of the final draft. The working group co

17、mmenced work in March 2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungar

18、y, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 15237:2007 (E) 4 1 Scope This European Standard establishes general principles for the execution, testing, supervisi

19、on and monitoring of vertical drain projects. This European Standard includes the application of prefabricated vertical drains and sand drains and deals with requirements to be placed on design, drain material and installation methods. This European Standard applies to the improvement of low-permeab

20、ility, highly compressible soils by vertical drainage and preloading. Information regarding loading (embankment, vacuum or ground water lowering) and preloading is given in informative Annexes A and B. Vertical drainage is used both in on land and in marine constructions for the following purposes:

21、(pre-)consolidation and reduction of post-construction settlements; speeding up the consolidation process by decreasing the path lengths for pore water dissipation; increase of stability (by increasing effective stresses in the soil); groundwater lowering; mitigation of liquefaction effects. In each

22、 case there is an overall treatment of the soil (the volume of the drains is small in relation to the soil volume treated). This European Standard does not include soil improvement by means of wells, gravel and stone columns, large-diameter geotextile enclosed columns or reinforcing elements. Vertic

23、al drainage can also be combined with other foundation or ground improvement methods, e.g. electro-osmosis, piles and compacted sand piles, dynamic compaction and deep mixing. Guidance on practical aspects of vertical drainage, such as investigation of drain properties, execution procedures and equi

24、pment, is given in Annex A. Investigation of soil characteristics and assessment of design parameters, which are affected by drain properties and execution, are presented in Annex B. 2 Normative references The following referenced documents are indispensable for the application of this document. For

25、 dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 19971, Eurocode 7: Geotechnical design Part 1: General rules EN 19972, Eurocode 7: Geotechnical design Part 2: Ground investigation and test

26、ing EN 13252:2000, Geotextiles and geotextile-related products Characteristics required for use in drainage systems EN ISO 9862, Geosynthetics Sampling and preparation of test specimens (ISO 9862:2005) EN ISO 10319, Geotextiles Wide-width tensile test (ISO 10319:1993) EN ISO 10320, Geotextiles and g

27、eotextile-related products Identification on site (ISO 10320:1999) EN 15237:2007 (E) 5 EN ISO 10321, Geotextiles Tensile test for joints/seams by wide-width method (ISO 10321:1992) EN ISO 11058, Geotextiles and geotextile-related products Determination of water permeability characteristics normal to

28、 the plane, without load (ISO 11058:1999) EN ISO 12956, Geotextiles and geotextile-related products Determination of the characteristic opening size (ISO 12956:1999) EN ISO 12958:1999, Geotextiles and geotextile-related products Determination of water flow capacity in their plane (ISO 12958:1999) EN

29、 ISO 14688 (all parts), Geotechnical investigation and testing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 auger installation method fr: installation la tarire de: Schneckeneinbauverfahren installation method of sand drains by means of sc

30、rew type auger or continuous flight hollow stem auger 3.2 band drain1)fr: drain plat de: Streifendrn prefabricated drain with a rectangular cross-section, usually consisting of a central core with a channel system surrounded by a filter sleeve 3.3 cylindrical prefabricated drain fr: drain tubulaire

31、de: zylindrischer Drn drain consisting of an annular-corrugated and perforated open core, surrounded by a filter sock 3.4 discharge capacity qwfr: capacit de dcharge de: Durchflusskapazitt discharge capacity of a drain well is equal to the cross-sectional area of the drain multiplied by its overall

32、permeability in longitudinal direction (the volume of water which flows out of the drain per time unit under a hydraulic gradient equal to unity) 3.5 displacement installation method fr: installation par fonage refoulant de: Verdrngungseinbauverfahren installation method of drains by means of a clos

33、ed-end steel tube/mandrel 1)The terms “wick drains” and “prefabricated vertical drains” (PVD) are also used. EN 15237:2007 (E) 6 3.6 drain anchor fr: sabot dancrage de: Drnschuh anchor fixed at the end of band drains before installation and which prevents soil from intruding into the mandrel during

34、installation and the band drain from being dragged up when the mandrel is withdrawn 3.7 drainage blanket fr: tapis drainant de: Drndecke upper high-permeability drainage layer, which has good contact with the drains and prevents the creation of backpressure in the drains 3.8 dynamic installation met

35、hod fr: mthode dinstallation par battage ou vibrofonage de: dynamische Drneinbauweise drain installation method using dynamic action (impact or vibratory hammer) 3.9 geotextile enclosed sand drain fr: drains de sable dans une gaine de gotextile de: geotextilumschlossener Sanddrn sand drains enclosed

36、 in some type of filter fabric made of geotextile 3.10 jet installation method fr: mthode dinstallation par lanage de: Einbau mittels Hochdruckinjektion installation method of sand drains by means of internal jetting or rotary jet 3.11 sand drain fr: drain de sable de: Sanddrn drain with circular cr

37、oss-section, built up of granular material (sand, gravel) with high permeability 3.12 static installation method fr: mthode dinstallation par fonage de: statisches Einbauverfahren drain installation method by means of static load (pushing) 3.13 vibro installation method fr: mthode dinstallation par

38、vibrofonage de: Vibrationseinbauverfahren installation method of sand drains by means of a top vibrator mounted on a hollow mandrel or by a depth vibrator 3.14 working platform fr: plateforme de travail de: Arbeitsebene platform created for access of the drain installation machines to the location o

39、f the vertical drains EN 15237:2007 (E) 7 4 Information needed for the execution of the work 4.1 Prior to the execution of the work, all necessary information shall be available. 4.2 This information shall include: a) relevant information regarding the site conditions; b) the location of main grid l

40、ines for setting out; c) drawings with the location and length of the drains; d) any legal or statutory restrictions; e) method statement for the vertical drain installation (see 8.1); f) characteristics of the drains (physical and hydraulic characteristics), accompanying document for CE-marking; g)

41、 specification for the drains and other materials to be used (see Clause 6) and the schedule of any testing and acceptance procedures for materials incorporated in the works; h) description of a suitable quality management system, including supervision and monitoring. 4.3 The information regarding t

42、he site conditions shall cover, where relevant: a) the geometry of the site (boundary conditions, topography, access, slopes, headroom restrictions etc.); b) the ground properties of the site which may influence the execution of the vertical drains: soil description (soil type, soil stratification a

43、nd existence and frequency of sand and silt layers, hard layers); penetration resistance (e.g. results of penetration tests); composition, lateral extent, thickness and firmness of the surface stratum, tree roots, fill etc.; presence of cobbles or boulders or cemented layers that can cause difficult

44、ies for the execution or can require special installation equipment; c) the following climatic and environmental information: weather information in areas with extreme climatic conditions; marine conditions (currents, tidal movements, wave heights etc.); environmental hazards (any water and subsoil

45、contamination, which could affect the execution method, the safety of the work or the discharge of excavation material from the site shall be documented, including the presence of hazardous gas and occurrence of unexploded ammunition); d) the existing underground structures, services, known contamin

46、ation and archaeological constraints; e) the environmental restrictions, including noise, vibration and pollution; f) planned or ongoing construction activities, such as dewatering, tunnelling and deep excavations; g) previous experience from drain installation work adjacent to the site; EN 15237:20

47、07 (E) 8 h) the characteristics of the working platform and the drainage layer (physical and hydraulic properties); i) the conditions of structures, roads, services etc. adjacent to the work. 4.4 For the loading operation the following information shall be available: a) construction programme for lo

48、ading; b) preloading (temporary and permanent loading); c) time schedule for loading and possible preloading; d) unit weight of fill used for preloading; e) notice of any restrictions such as construction phasing required in the design; f) monitoring programme. 4.5 The following instructions shall a

49、lso be given: a) reporting procedure for unforeseen circumstances, or conditions revealed that appear to be different from those assumed in the design; b) reporting procedure, if an observational method of design is adopted. 4.6 Any additional or deviating requirements falling within the permission clauses given in this European Standard shall be established and agreed upon before the commencement of the works. 5 Geotechnical investigations 5.1 General 5.1.1 The geotechnical investigations carried