Geosynthetics - Determination of friction characteristics - Part 1: Direct shear test (ISO 12957-1:2005)

ISO 12957-1:2005 describes a method of determining the friction characteristics of geotextiles and geotextile-related products in contact with a standard sand, i.e. sand with a specified density and moisture content, under a normal stress and at a constant rate of displacement, using a direct shear apparatus.
The procedure can also be used for testing geosynthetic barriers.

Geokunststoffe - Bestimmung der Reibungseigenschaften - Teil 1: Scherkastenversuch (ISO 12957-1:2005)

Diese Norm beschreibt ein Verfahren zur Bestimmung der Reibungskenngrößen von Geotextilien und geotextilverwandten Produkten in Kontakt mit einem Normsand, b ei genormter Dichte, Feuchte, Normalspannung und konstanter Verschiebegeschwi ndigkeit in einem Schergerät. Das Verfahren kann auch für Prüfungen mit Geomembranen/-Dichtungsbahnen benutzt werden.  Das angegebene Verfahren ist ein Inde xprüfverfahren.

Géosynthétiques - Détermination des caractéristiques de frottement - Partie 1: Essai de cisaillement direct (ISO 12957-1:2005)

L'ISO 12957-1:2005 décrit une méthode de détermination des caractéristiques en frottement des géotextiles et des produits apparentés, en contact avec un sable normalisé, à une masse volumique et avec une teneur en humidité spécifiées, sous l'effet d'une contrainte normale et à une vitesse de déplacement constante, en utilisant un dispositif de cisaillement direct.
Le mode opératoire peut également être utilisé pour les essais sur géomembranes et géosynthétiques bentonitiques.

Geosintetika - Ugotavljanje tornih značilnosti - 1. del: Neposredni strižni preskus (ISO 12957-2:2005)

General Information

Status
Withdrawn
Publication Date
14-Feb-2005
Withdrawal Date
18-Dec-2018
Current Stage
9960 - Withdrawal effective - Withdrawal
Completion Date
19-Dec-2018

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SLOVENSKI STANDARD
SIST EN ISO 12957-1:2005
01-maj-2005

*HRVLQWHWLND8JRWDYOMDQMHWRUQLK]QDþLOQRVWLGHO1HSRVUHGQLVWULåQLSUHVNXV

,62

Geosynthetics - Determination of friction characteristics - Part 1: Direct shear test (ISO

12957-1:2005)

Geokunststoffe - Bestimmung der Reibungseigenschaften - Teil 1: Scherkastenversuch

(ISO 12957-1:2005)

Géosynthétiques - Détermination des caractéristiques de frottement - Partie 1: Essai de

cisaillement direct (ISO 12957-1:2005)
Ta slovenski standard je istoveten z: EN ISO 12957-1:2005
ICS:
59.080.70 Geotekstilije Geotextiles
SIST EN ISO 12957-1:2005 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 12957-1:2005
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SIST EN ISO 12957-1:2005
EUROPEAN STANDARD
EN ISO 12957-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2005
ICS 59.080.70
English version
Geosynthetics - Determination of friction characteristics - Part 1:
Direct shear test (ISO 12957-1:2005)

Géosynthétiques - Détermination des caractéristiques de Geokunststoffe - Bestimmung der Reibungseigenschaften -

frottement - Partie 1: Essai de cisaillement direct (ISO Teil 1: Scherkastenversuch (ISO 12957-1:2005)

12957-1:2005)
This European Standard was approved by CEN on 18 November 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national

standards 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 translation

under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official

versions.

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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12957-1:2005: E

worldwide for CEN national Members.
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SIST EN ISO 12957-1:2005
EN ISO 12957-1:2005 (E)
Contents
page

Foreword......................................................................................................................................................................3

1 Scope.....................................................................................................................................................................4

2 Normative references...........................................................................................................................................4

3 Terms and definitions ..........................................................................................................................................4

4 Principle.................................................................................................................................................................5

5 Test specimens.....................................................................................................................................................5

6 Conditioning.........................................................................................................................................................5

7 Apparatus..............................................................................................................................................................6

8 Procedure..............................................................................................................................................................8

9 Calculations..........................................................................................................................................................9

10 Test report...........................................................................................................................................................10

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SIST EN ISO 12957-1:2005
EN ISO 12957-1:2005 (E)
Foreword

This document (EN ISO 12957-1:2005) has been prepared by Technical Committee CEN/TC 189 "Geosynthetics",

the secretariat of which is held by IBN, in collaboration with Technical Committee ISO/TC 221 "Geosynthetics".

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 2005, and conflicting national standards shall be withdrawn at the latest by

August 2005.

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.

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SIST EN ISO 12957-1:2005
EN ISO 12957-1:2005 (E)
1 Scope

This document describes an index test method to determine the friction characteristics of geotextiles and

geotextile-related products in contact with a standard sand, i.e. with a specified density and moisture content, under

a normal stress and at a constant rate of displacement, using a direct shear apparatus.

The procedure can also be used for testing geosynthetic barriers.

When geogrids are tested with a rigid support, the results are dependent on the friction with the support and the

results are not necessarily realistic. The accuracy of the test should be verified by calibration tests.

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.
ISO 554, Standard atmospheres for conditioning and/or testing -– Specifications.

ISO 6344-2, Coated abrasives – Grain size analysis – Part 2: Determination of grain size distribution of macrogrits

P 12 to P 220.

EN ISO 9862, Geotextiles – Sampling and preparation of test specimens (ISO 9862:2005).

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
relative displacement (s)

displacement of the sand relative to the specimen during shearing, in millimetres

3.2
normal force (N)
constant vertical force applied to the specimen, in kilonewtons
3.3
shear force (S)

horizontal force, measured during shearing at a constant rate of displacement, in kilonewtons

3.4
normal stress (σσσσ)
normal force divided by the contact area of the specimen, in kilopascals
3.5
shear stress (ττττ)

shear force along the sand/geotextile interface, divided by the contact area of the specimen, in kilopascals

3.6
max
maximum shear stress (ττττ )
maximum value of shear stress developed in a shear test, in kilopascals
3.7
angle of friction (φφ ) (between geosynthetic and sand)

slope of the "best fit straight line", through the plot of maximum shear stress, in degrees

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SIST EN ISO 12957-1:2005
EN ISO 12957-1:2005 (E)
3.8
apparent cohesion (c ) (between geosynthetic and sand)

calculated value of the shear stress on the "best fit straight line" corresponding to zero normal stress, in kilopascals

3.9
max
maximum shear stress in sand ( )
maximum shear stress developed during a shear test on sand alone, in kilopascals
3.10
max
sup
maximum shear stress sand/support ( )

maximum shear stress developed during the shearing along the sand/support interface (without geosynthetic), in

kilopascals
3.11
friction ratio (f (σσσσ))
max
max

ratio of the maximum shear stress τ (friction test sand/geosynthetic) to the maximum shear stress τ

(shear test on sand alone) for the same normal stress σ
4 Principle

A geosynthetic is submitted to direct shear at its contact surface with standard sand in a shear box or similar

apparatus. The angle of friction at the sand/geosynthetic interface is determined.

5 Test specimens
5.1 Sampling
Take specimens in accordance with EN ISO 9862.
5.2 Number and dimensions of test specimens

Cut four specimens from the test sample for each direction to be tested. The size of the specimens shall suit the

dimensions of the apparatus.

If the two faces of the sample are different, both faces shall be tested; four specimens shall be tested for each face.

6 Conditioning

Condition the test specimens and conduct the tests in the standard atmosphere for testing, defined in ISO 554, i.e.

at a temperature of (20 + 2) °C and a relative humidity of (65 + 2) %, until the change in mass between successive

readings made at intervals of not less than two hours does not exceed 0,25 % of the mass of the test specimens.

NOTE Conditioning and/or testing at a specified relative humidity may be omitted if it can be proved that the results are not

affected by this omission.
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SIST EN ISO 12957-1:2005
EN ISO 12957-1:2005 (E)
7 Apparatus
7.1 Shearing apparatus
7.1.1 Constant contact area shear box (schematically represented in Figure 1)

The shear box shall be divided into upper and lower sections. The apparatus shall be sufficiently rigid to resist

...

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