nordic guidelines for reinforced soils and fills - Dansk Geoteknisk

204 Pages·2004·4.1 MB·English

NORDIC GUIDELINES
FOR
REINFORCED SOILS AND FILLS

Nordic Geosynthetic Group
A section of Nordic Geotechnical Societies
Nordic Industrial Fund
Yvonne Rogbeck, Claes Alén, Gunilla Franzén, Anders Kjeld,
Karin Odén, Hans Rathmayer, Arnstein Watn, Even (cid:216)iseth

NORDIC GUIDELINES
FOR
REINFORCED SOILS AND FILLS

Nordic Geosynthetic Group

May 2003

Revision A – February 2004
Published by The Nordic Geotechnical Societies
Nordic Industrial Fund

Date May 2003
Revision A – February 2004

Distribution paper SGI
version Phone: [phone]
FAX: [phone]
e-post: [email protected]

Digital version Down-load digital version at www.sgf.net

Photo on the front page Reinforced wall Anders Kjeld
Reinforced slope Anders Kjeld
Soil Nailing wall Gunilla Franzén
Embankment on improved soil Hartmut Hangen
Preface

PREFACE
These Nordic guidelines for strenghtened/reinforced soils and fills is published by the
Geotechnical Societies in the Nordic countries and the Nordic Industrial Fund.

The Nordic Geosynthetic Group (NGG) has initiated these guidelines. The group is
organised by the Nordic Geotechnical Societies. NGG has been the project management
group. The guidelines have been prepared by a project group. It has been financed by 29
organisations including the companies for the project group. The other organisations have
been engaged in the reference group. The large reference group has been valuable to gain
approval to the content in the guidelines.

The book is only gives guidelines and the designers have full responsibility. . Engineering
judgement should be applied to determine when the recommendations are relevant to every
specific object. The guideline is intended for engineers with experience of geotechnical
works.

The purpose of these guidelines is to increase the knowledge of reinforced soil and to make
it easier to use these types of structures. The reinforced soil structures are often more
economical than conventional structures. The applications included in these guidelines are:
• Vertical walls and slopes
• Embankment on soft soil
• Embankment on improved soil
• Soil-nailing (excavated walls and natural slopes)

The guidelines include chapters on:
• Materials and testing
• Design
• Execution
• Quality control
• Procurement

The use of soil reinforcement technique has been increasing during the past decade in the
Nordic countries. In Norway the use of reinforced walls started earlier and is more
common than in the other Nordic countries. In Sweden piled embankment is a common
soil improvement method and during the last years it has been commonly combined with
reinforcement in the fill. Some guidelines already exist in some of the Nordic countries but
the purpose with these guidelines is to use partial factors in the design according to
Eurocode.

The guidelines concerning design of reinforced fill are mainly for the use of polymeric
reinforcement but some guidelines are also given for stiffer reinforcements.

The work with Eurocodes is still in progress. ENV 1991-1, Basis of Design and Actions of
Structures is going to be a norm soon. The difference between existing ENV 1997-1,
Geotechnical Design and prEN 1997-1 is considerable. For these guidelines existing ENVs
have been chosen as the base. When the Eurocodes have been approved as ENs these
guidelines might need a revision depending on the outcome of the ENs. National
Nordic Guideline for Reinforced Soils and Fills I
Preface

Application Documents (NAD) are made as a complement to the ENVs and are different in
the Nordic countries. Concerning these guidelines there are only NAD ruling in Sweden
and Norway and figures from these are refereed in Annex B.

The intention with the guidelines is that all design work should be able to calculate by
hand. For more complex objects or a faster procedure there are computer programs on the
market, but in these guidelines there are no recommendations made to existing programs.
They have to be evaluated by the designers.

To get a better understanding of the consequences of using partial factors it would be
useful to make consequence analyses. However, this is not included in this project.

These guidelines is written in English to be able to get feed back also for persons outside
the Nordic countries. The guidelines are translated to Norwegian and Swedish during 2003
and published by the Geotechnical societies in Denmark, Norway, Sweden and Finland in
corporation with the Nordic Industrial Fund.

The project organisation is presented below.

Project Management Group (NGG excluding delegates from project group)
Ingrid Södergren, The National Railroad Administration, Sweden, Chair person
Torbjörn Eng, Engtex AB, Sweden
Per Kristian Hoel, Nordisk Kartro AS/Viacon, Norway
Lovisa Moritz, The National Road Administration, Sweden
Oddur Sigurdsson, VSO Consulting, Iceland
Alexander Smekal, The National Railroad Administration, Sweden
Erik Ramberg Steen, Fibertex A/S, Denmark

Project Group
Yvonne Rogbeck, Swedish Geotechnical Institute, Project leader
Claes Alén, Swedish Geotechnical Institute, Sweden
Gunilla Franzén, Ramböll, Sweden
Anders Kjeld, Byggros, Denmark
Karin Odén, Swedish Geotechnical Institute, Sweden
Hans Rathmayer, VTT Technical Research Centre of Finland
Arnstein Watn, Sintef, Norway
Even Øiseth, Sintef, Norway

Reference Group
DENMARK
Bjarne Landgrebe, A/S Skandinavisk Spændbeton
Jørgen Larsen, GEO-Geoteknisk institut
Nils Krebs Ovesen, GEO-Geoteknisk institut
Jørgen S. Steenfelt, COWI Consulting Engineers and Planners AS
FINLAND
Jouko Lehtonen/Hannu Jokiniemi, Rautaruukki Oyj
Pasi Leimi, RHK Finnish Rail Administration
Tim Länsivaara, SCC Viatek Ab
II Nordic Guideline for Reinforced Soils and Fills
Preface

Penti Salo, Finnish Road Administration
Marcus Sjöholm, Oy ViaPipe Ab /Gävle Vägtrummor AB
NORWAY
Roald Aabøe, Vegdirektoratet
Hans Bugge, Teletextiles
Hasse Ekegren, Nordic Industrial Fund
Steinar Herrmann, Norwegian Geotechnical Institute
Jan Vaslestad, VIACON
Terje Rykhus, SR/BR avd GeoPro
SWEDEN
Torbjörn Allenius/Markus Kappling, Golder Associates AB
Bo Berggren/Torbjörn Edstam, WSP Samhällsbyggnad
Onni Henriksson, FLA Utveckling AB
Erik Knudsen, Hedareds Sand & Betong
Sten-Eric Lager, VIACON
Philip Landkvist, PEAB Grundläggning AB
Per Löfling/Peter Zakrisson, Vägverket konsult
Rolf Mattsson, De Neef Scandinavia

Tord Sjödahl/Ulf Alenius, Tyréns
GERMANY
Hartmut Hangen, Huesker
ITALY
Marco Vicari, Macca Ferri S.P.A.

Nordic Guideline for Reinforced Soils and Fills III

Table of Content

Table of Content

PREFACE..................................................................................................................................................I
1 INTRODUCTION............................................................................................................................1
1.1 SCOPE.......................................................................................................................................1
1.2 INTRODUCTION OF THE METHODS...............................................................................................3
1.2.1 Reinforced steep slopes and walls.........................................................................................3
1.2.2 Embankment on soft subsoil..................................................................................................3
1.2.3 Embankment on improved soil..............................................................................................4
1.2.4 Soil-nailing...........................................................................................................................4
1.3 NOTATIONS AND SYMBOLS.........................................................................................................5
1.3.1 Definitions............................................................................................................................5
1.3.2 Units recommended for geotechnical calculations.................................................................8
1.3.3 Symbols................................................................................................................................8
1.4 TRANSLATION OF TEXT IN FIGURES...........................................................................................11
2 MATERIALS AND TESTING OF MATERIAL..........................................................................13
2.1 FILL REINFORCEMENT..............................................................................................................13
2.1.1 Reinforcement products......................................................................................................13
2.1.2 Fill materials......................................................................................................................20
2.1.3 Drainage............................................................................................................................22
2.1.4 Facing................................................................................................................................22
2.1.5 Testing of material..............................................................................................................24
2.2 SOIL-NAILING..........................................................................................................................25
2.2.1 Main parts..........................................................................................................................25
2.2.2 Reinforcing element............................................................................................................25
2.2.3 Soil.....................................................................................................................................27
2.2.4 Interface between soil and nail............................................................................................28
2.2.5 Drainage............................................................................................................................31
2.2.6 Corrosion protection system...............................................................................................31
2.2.7 Facing................................................................................................................................32
3 PRINCIPLES OF DESIGN...........................................................................................................35
3.1 INTRODUCTION........................................................................................................................35
3.2 LIMIT STATE DESIGN................................................................................................................35
3.3 PARTIAL FACTORS...................................................................................................................36
3.4 APPLICATION OF PARTIAL FACTORS..........................................................................................37
3.5 REINFORCED SLOPE/SOIL-NAIL REINFORCED SLOPE...................................................................38
3.5.1 Traditional factor of safety..................................................................................................38
3.5.2 Partial factor Factor Format..............................................................................................39
3.5.3 Application of partial factor format in stability calculations................................................40
3.6 DESIGN REQUIREMENTS...........................................................................................................41
3.6.1 Design working life.............................................................................................................41
3.6.2 Class of safety....................................................................................................................41
3.6.3 Geotechnical category........................................................................................................42
3.6.4 Design method....................................................................................................................42
3.6.5 Actions...............................................................................................................................43
3.6.6 Design values of actions.....................................................................................................43
3.6.7 Combinations of actions.....................................................................................................44
3.7 GEOMETRICAL PROPERTIES......................................................................................................45
3.8 MATERIAL PROPERTIES............................................................................................................45
3.8.1 Characteristic values..........................................................................................................45
3.8.2 Design values.....................................................................................................................45
Nordic Guideline for Reinforced Soils and Fills V
Table of Content

4 REINFORCED STEEP SLOPES AND WALLS...........................................................................49
4.1 INTRODUCTION........................................................................................................................49
4.1.1 Function of the reinforcement.............................................................................................49
4.2 SPECIFIC INFORMATION NEEDED FOR DESIGN.............................................................................50
4.2.1 Geometry and foundation properties...................................................................................50
4.3 ULITIMATE LIMIT STATE DESIGN..............................................................................................51
4.3.1 Design values and design loads...........................................................................................52
4.3.2 Design step by step.............................................................................................................54
4.4 SERVICEABILITY LIMIT STATE DESIGN......................................................................................59
4.4.1 Settlements and displacements.............................................................................................60
4.5 DRAINAGE AND WATER PRESSURE............................................................................................60
4.6 FACINGS..................................................................................................................................62
4.7 DURABILITY............................................................................................................................62
4.8 EXECUTION, QUALITY CONTROL AND PROCUREMENT.................................................................63
5 EMBANKMENTS ON SOFT SUBSOIL.......................................................................................65
5.1 INTRODUCTION........................................................................................................................65
5.1.1 Function of the reinforcement.............................................................................................65
5.1.2 Calculation principles.........................................................................................................65
5.2 SPECIFIC INFORMATION NEEDED FOR DESIGN.............................................................................65
5.2.1 Design life time...................................................................................................................66
5.2.2 Geometry and foundation properties...................................................................................66
5.3 ULTIMATE LIMIT STATE DESIGN...............................................................................................66
5.3.1 Failure modes.....................................................................................................................66
5.3.2 Design values and design loads...........................................................................................67
5.3.3 Design step by step.............................................................................................................67
5.4 SERVICEABILITY LIMIT STATE DESIGN......................................................................................74
5.4.1 Foundation settlements.......................................................................................................74
5.4.2 Reinforcement strains.........................................................................................................74
5.5 DURABILITY............................................................................................................................75
5.6 EXECUTION, QUALITY CONTROL AND PROCUREMENT.................................................................75
6 EMBANKMENT ON IMPROVED SOIL (REINFORCED PILED EMBANKMENTS).............77
6.1 INTRODUCTION........................................................................................................................77
6.1.1 Function of the reinforcement.............................................................................................77
6.1.2 Calculation principles.........................................................................................................77
6.2 SPECIFIC INFORMATION NEEDED FOR DESIGN.............................................................................78
6.3 ULTIMATE LIMIT STATES DESIGN.............................................................................................78
6.3.1 Failure modes.....................................................................................................................78
6.3.2 Design values and design loads...........................................................................................79
6.3.3 Partial factors of safety.......................................................................................................79
6.3.4 Restrictions of the model.....................................................................................................80
6.3.5 Design step by step.............................................................................................................81
6.4 SERVICEABILITY LIMIT STATES DESIGN....................................................................................85
6.5 DURABILITY............................................................................................................................85
6.6 EXECUTION, QUALITY CONTROL AND PROCUREMENT.................................................................86
7 SOIL NAILING..............................................................................................................................87
7.1 EXCAVATED SOIL NAILED SLOPE..............................................................................................87
7.1.1 Specific information needed for design................................................................................87
7.1.2 Ultimate limit state design...................................................................................................88
7.1.3 Serviceability limit state design...........................................................................................93
7.1.4 Drainage............................................................................................................................95
7.1.5 Facing................................................................................................................................95
7.1.6 Durability...........................................................................................................................95
7.2 NATURAL SLOPES...................................................................................................................100
7.2.1 Specific information needed for design..............................................................................100
7.2.2 Ultimate limit state design.................................................................................................101
7.2.3 Serviceability limit state design.........................................................................................101
7.2.4 Drainage..........................................................................................................................101
VI Nordic Guideline for Reinforced Soils and Fills