1、BRITISH STANDARDBS EN 14731:2005Execution of special geotechnical works Ground treatment by deep vibrationThe European Standard EN 14731:2005 has the status of a British StandardICS 93.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51
2、g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14731:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 24 November 2005 BSI 24 November 2005ISBN 0 580 47281 7National forewordThis British Stand
3、ard is the official English language version of EN 14731:2005.The UK participation in its preparation was entrusted to Technical Committee B/526, Geotechnics, which has the responsibility to:A list of organizations represented on this committee can be obtained on request to its secretary.Cross-refer
4、encesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British
5、Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to t
6、he responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front c
7、over, the EN title page, pages 2 to 24, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14731September 2005
8、ICS 93.020English VersionExecution of special geotechnical works - Ground treatment bydeep vibrationExcution de travaux gotechniques spciaux -Amlioration des massifs de sol par vibrationAusfrung von besonderen geotechnischen Arbeiten(Spezialtiefbau) - Baugrundverbesserung durchTiefenrttelverfahrenTh
9、is European Standard was approved by CEN on 8 August 2005.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 reference
10、s 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
11、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, Luxembou
12、rg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitat
13、ion in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14731:2005: EEN 14731:2005 (E) 2 Contents page Foreword 4 1 Scope .5 2 Normative references .5 3 Terms and definitions.6 4 Information needed for the execution of the work .7 4.1 General 7 4.2 Special features fo
14、r ground treatment by deep vibration 7 5 Geotechnical investigation.8 5.1 General 8 5.2 Specific aspects for deep vibratory compaction8 5.3 Specific aspects for vibrated stone columns .9 6 Materials and products.9 6.1 General 9 6.2 Materials for deep vibratory compaction 9 6.3 Materials for vibrated
15、 stone columns9 7 Considerations related to design.10 7.1 General 10 7.2 Selection of treatment method.10 7.3 Design verification11 7.4 Extent and layout of treatment.11 7.5 Sequence of treatment .11 8 Execution.12 8.1 General 12 8.2 Site preparation.12 8.3 Setting out .12 8.4 Treatment.12 9 Supervi
16、sion, testing and monitoring.13 9.1 Supervision and monitoring.13 9.2 Testing .14 10 Records .15 10.1 Records in connection with the execution of the ground treatment.15 10.2 Records at completion of the ground treatment 16 11 Special requirements16 11.1 General 16 EN 14731:2005 (E) 3 11.2 Safety.16
17、 11.3 Environmental protection.16 11.4 Impact on adjacent structures .17 Annex A (informative) Deep vibratory compaction18 Annex B (informative) Installation of vibrated stone columns20 B.1 General 20 B.2 Dry top-feed process 20 B.3 Wet process.21 B.4 Dry bottom-feed process22 Bibliography.24 EN 147
18、31:2005 (E) 4 Foreword This European Standard (EN 14731:2005) 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
19、 identical text or by endorsement, at the latest by March 2006, and conflicting national standards shall be withdrawn at the latest by March 2006. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European S
20、tandard: 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. EN 14731:2005 (E) 5
21、 1 Scope This European Standard is applicable to the planning, execution, testing and monitoring of ground treatment by deep vibration achieved by depth vibrators and compaction probes. The following types of treatment are covered by this European Standard: deep vibratory compaction to densify the e
22、xisting ground; vibrated stone columns to form a stiffened composite ground structure by the insertion of granular material which itself shall be densified. Generally, stone columns have a diameter greater than 0,6 m and lower than 1,2 m. The following treatment methods are covered by this European
23、Standard: methods in which depth vibrators, containing oscillating weights which cause horizontal vibrations, are inserted into the ground; methods in which compaction probes are inserted into the ground using a vibrator which remains at the ground surface and which in most cases oscillates in a ver
24、tical mode. Treatment methods are outlined in Annexes A and B. The following treatment methods, among others, are not included in this European Standard: methods in which sand or stone columns are installed by means of impact or top vibratory driven casing; methods in which very stiff columns are fo
25、rmed either by the addition of cement to granular material or by the use of concrete or any other binder; dynamic compaction and other methods in which some form of treatment is applied to the ground surface; explosive compaction. 2 Normative references The following referenced documents are indispe
26、nsable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 791, Drill rigs Safety EN 996, Piling equipment Safety requirements EN 1990, Euroco
27、de: Basis of structural design EN 1997-1:2004, Eurocode 7: Geotechnical design Part 1: General rules prEN 1997-2, Eurocode 7: Geotechnical design Part 2: Ground investigation and testing EN 14731:2005 (E) 6 3 Terms and definitions For the purposes of this European Standard, the following terms and d
28、efinitions apply. Additional descriptions of some of the ground treatment methods are given in Annexes A and B. 3.1 deep vibratory compaction type of ground treatment by deep vibration in which the main purpose is to densify the soil. The treatment is applicable to many granular soils and normally r
29、esults in increased strength and stiffness, reduced permeability and reduced susceptibility to liquefaction 3.2 vibrated stone columns1)type of ground treatment by deep vibration in which a depth vibrator is used to form continuous stone columns from the maximum depth of penetration up to the ground
30、 surface, and hence to form a stone column/soil structure which should have an increased strength and stiffness compared with the ground in an untreated state. The treatment is applicable to a wide range of soils and in granular soils some densification may also be achieved. Three installation proce
31、sses, the dry top-feed process, the wet process and the dry bottom-feed process are described in Annex B 3.3 vibrating tool item of equipment which is inserted into the ground to cause vibration at depth; commonly a depth vibrator containing oscillating weights or a compaction probe inserted into th
32、e ground using a top vibrator which remains at the ground surface 3.4 depth vibrator basic component of ground treatment equipment used in the installation of vibrated stone columns and in vibro compaction, which vibrates horizontally by means of an eccentric weight rotating about its longitudinal a
33、xis, and penetrates into the ground. The penetration in the ground can be made easier by air or water flushing 3.5 top vibrator vibrator which remains above the ground surface 3.6 compaction probe tool for deep vibratory compaction which is inserted into the ground to transmit vibrations from a top
34、vibrator which remains at the ground surface; wings, drainage or water flushing can be provided to facilitate the compaction process 3.7 deep vibro compaction technique in which a depth vibrator is used to compact granular soil with or without the formation of stone columns 3.8 dry top-feed process
35、method of installing vibrated stone columns in which the hole formed by the depth vibrator remains open and specified granular material is fed directly into the top of the hole and compacted by the vibrator in stages (the process is described in Annex B) 1) Commonly termed vibro stone columns. EN 14
36、731:2005 (E) 7 3.9 wet process method of installing vibrated stone columns in which flushing water removes soft material, stabilises the hole and allows specified granular material to reach the tip of the depth vibrator where it is compacted (the process is described in Annex B) 3.10 dry bottom-feed
37、 process method of installing vibrated stone columns in which specified granular material is delivered directly to the tip of the vibrator via a feed pipe attached to the vibrator, with the vibrator remaining in the ground during the construction of the column to maintain the stability of the hole (
38、the process is described in Annex B) 4 Information needed for the execution of the work 4.1 General 4.1.1 Prior to the execution of the work, all necessary information shall be provided 4.1.2 The information should include: a) any legal or statutory restrictions; b) location of main grid lines or re
39、ference points for setting out; c) condition of structures, roads and services adjacent to the work; d) suitable quality management system, including supervision, monitoring and testing. 4.1.3 The information regarding the site conditions shall cover, where relevant: a) geometry of the site includin
40、g boundary conditions, topography, access, slopes and headroom restrictions; b) existing underground structures, services, known contaminants and archaeological constraints; c) environmental restrictions including noise, vibration, displacements, pollution and effects of seasonal variations in weath
41、er including frozen surface layers; d) future or ongoing activities such as dewatering, tunnelling, deep excavations and raising of site levels. 4.1.4 Other information which will be required is described in Clauses 5, 6, 7 and 8. 4.2 Special features for ground treatment by deep vibration The infor
42、mation required in relation to the practical aspects of the execution of ground treatment shall include: specific project design objectives which the execution of the ground treatment is intended to fulfil; water supply and slurry disposal requirements for the wet process of installing vibrated ston
43、e columns. EN 14731:2005 (E) 8 5 Geotechnical investigation 5.1 General 5.1.1 All site investigation shall be undertaken in accordance with EN 1997-1 and prEN 1997-2, and the design of the project. 5.1.2 The extent and depth of the site investigation shall be sufficient to determine the characterist
44、ic ground conditions and topography of the site and to identify and locate all ground formations, layers, other geological features and ground water levels affecting the execution of the works. 5.1.3 All information from site investigations shall be made available in accordance with the requirements
45、 of Clause 4. 5.1.4 Some fills may be heterogeneous and examination in trial pits may be required for a representative geotechnical description. 5.1.5 Obstructions, hard layers and cobbles and boulders within the ground which would influence or prevent the insertion of the vibrating tool should be i
46、dentified. 5.1.6 The presence of ground conditions which will affect the performance of treatment shall be identified including: hard layers; soils sensitive to disturbance; soils with potential for collapse settlement on wetting; soils with liquefaction potential; fills currently settling under sel
47、f-weight. 5.1.7 Any contaminants and pollutants in the soil or the groundwater should be identified. 5.2 Specific aspects for deep vibratory compaction 5.2.1 Special consideration shall be given to the extent of the treatable granular soils and the location and extent of any layers which restrict or
48、 reduce the efficiency of the treatment process including clay, silt and organic layers and layers preventing drainage. 5.2.2 Where clay, silt or organic soils are present, some or all the properties mentioned in 5.3 may be needed. 5.2.3 The following geotechnical properties of the granular soil may
49、 be relevant to the design and execution of ground treatment by deep vibratory compaction: particle size distribution and fines content; in situ density index (relative density); permeability; crushability of particles; inter-particle bonding caused by cementation, suction or cohesion. EN 14731:2005 (E) 9 5.3 Specific aspects for vibrated stone columns 5.3.1 Particular attention should be given to the determination of physical and geotechnical properties required for the design and execution of the ground treatment by vibrate
