ISO/TR 18228-5:2025
(Main)Design using geosynthetics — Part 5: Stabilization
Design using geosynthetics — Part 5: Stabilization
This document provides a summary of general guidance for the design of geosynthetics to fulfil the function of stabilization of granular layers in contact with natural soils, fills, asphalt or other materials. The concepts of the summarised guidance are based on installed materials, the installation process and on either the strength or deformation behaviour, or both, of geosynthetics. This document provides general considerations to support the design of unbound layers of paved and unpaved roads, working platforms and foundations utilizing the stabilization function of geosynthetics. This is typically for the serviceability limit state (SLS).
Conception utilisant des géosynthétiques — Partie 5: Stabilisation
General Information
Standards Content (Sample)
Technical
Report
ISO/TR 18228-5
First edition
Design using geosynthetics —
2025-01
Part 5:
Stabilization
Conception utilisant des géosynthétiques —
Partie 5: Stabilisation
Reference number
© ISO 2025
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Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Concepts and fundamental principles . 1
4.1 General .1
4.2 Benefits .3
4.3 Confinement and particle restraint .4
4.3.1 General .4
4.3.2 Internal confinement — Description of mechanism .4
4.3.3 External confinement — Description of mechanism .6
4.4 Vehicular action .9
4.5 Loading conditions (cyclic and static) .9
4.6 Multi component systems .10
4.7 Static loads — Settlement control and limitation .10
4.8 Reduction in deformation from trafficking .10
4.9 Reduction in unbound aggregate degradation .10
4.10 Extension of design life .11
4.11 Ground and groundwater conditions .11
4.12 Climatic conditions .11
4.13 Sustainability . 12
4.14 Impact of filtration, separation and drainage requirements . 12
5 Typical applications .12
5.1 Stabilized granular (aggregate) layers in trafficked areas . 12
5.2 Stabilized granular (aggregate) layers in railways . 13
5.3 Stabilized granular (aggregate) layers in working platforms .14
6 Design methods .15
6.1 General . 15
6.2 Unpaved roads . 15
6.2.1 Giroud-Han (2004) method . 15
6.2.2 Leng-Gabr (2006) method .17
6.2.3 Pokharel (2010) method for geocells .18
6.2.4 Emersleben (2009) method for geocells .19
6.3 Paved roads . 22
6.3.1 Modified American Association of State Highway and Transportation Officials
(AASHTO) (1993) method . 22
6.3.2 MEPDG methods .24
6.4 Working platforms and load transfer platforms . 25
6.4.1 General . 25
6.4.2 Static method for clay subgrade . 25
6.4.3 BCR method for soft sand subgrade .27
6.5 Railways . 28
6.5.1 Network Rail (UK) design specifications . 28
6.5.2 Ev2 method . 29
6.5.3 Railway ballast stabilization .31
6.5.4 Design method for railway stabilization with geocells .32
6.6 Design of the geosynthetics layout . 33
7 Materials .36
7.1 Properties of aggregate . 36
7.2 Key properties for geosynthetics – Internal confinement . 36
7.3 Key properties for geosynthetics – External confinement . 36
iii
8 Testing.37
8.1 General .37
8.2 Accelerated pavement tests (APT) .37
8.3 Tests for geotextiles and geogrids . 38
8.4 Tests for geocells . . . 38
Annex A (informative) Tensioned membrane design .40
Bibliography .43
iv
Foreword
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This document was prepared by Technical Committee ISO/TC 221, Geosynthetics.
A list of all parts in the ISO/TR 18228 series can be found on the ISO website.
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