Design of Piles Under Cyclic Loading

SOLCYP Recommendations

Alain Puech, Jacques Garnier, Alain Puech, Jacques Garnier

• Publisher: Wiley-ISTE
• Year: 2017
• Print ISBN: 9781786301987
• eBook ISBN: 9781119468943
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Mechanics

Recent developments in the fields of energy, transport and industrial engineering have led to the emergence of new types of structures and infrastructures subject to variable stresses, for which the usual methods for designing pile foundations are now inadequate. The recommendations presented in this book will help to partly fill this technical gap by proposing a methodological approach and calculation methods to take account of the effects of cyclic loads in the design of foundations on piles. These are based on both laboratory and full scale experiments, and on modeling carried out within the framework of the national SOLCYP project.

1
SOLCYP Project

1.1. Motivations

In the fields of civil engineering and marine engineering, the works and structures being designed, calculated and constructed are subjected to actions which can generally be described as “variable over time”. These actions are added to the constant actions (typically the forces of gravity).

The variable actions may have a significant influence on the behavior and stability of the constructions throughout their lifetime and, in the medium- and long term, lead to major defects and problems, potentially causing significant dysfunction or even the complete breakdown of the structure.

The oil industry has developed procedures to deal with the effects of powerful waves on the foundations of offshore structures. They are set out in the professional codes or recommendations (API RP2GEO [API 11]; DnV Foundations [DNV 92]; ISO 19901-4 [INT 03]). The wind power industry is gradually adapting these procedures to the case of offshore wind turbines (DnV-OS-J101 [DNV 14]; BSH [BSH 11]).

In parallel and surprisingly, the effect of cyclic stresses on the behavior of foundations is largely unknown in the domain of construction. There are a few wellknown exceptions such as the study of liquefaction of soils under seismic stresses, fatigue of roadways or railway banks. Generally speaking, though, there is – nationally, at the European (CEN) or international level (ISO) – no specific document (be it a standard, a regulatory text, a professional recommendation) explicitly discussing the risks linked to cyclic stresses and putting forward a methodological approach to take them into account when designing the foundations.

The insufficiency of the usual methods of foundations designing is increasingly apparent when developing new types of structures or infrastructures linked to the recent developments in the domains of energy, transport and industrial engineering.

These recommendations are intended to partly fill this technical and regulatory shortcoming, offering a methodological approach and computation methods to take account of the effects of variable loads in the design of pile foundations.

They are based on laboratory experiments, full-scale tests and simulations conducted as part of the SOLCYP project.

1.2. The SOLCYP project

The R&D program of the SOLCYP project was developed during the deliberations of a working group at the “soil” research hub at the IREX, set up in 2003 on the initiative of Pierre Vézole (Eiffage) and composed of about ten experts. It resulted in the definition of two complementary sections: a project – called ANR-SOLCYP – which obtained financing from France’s Agence nationale de la recherche and the certificate from the civil engineering/ecoconstruction hub, and a project – called PN-SOLCYP – organized as a national project with the financial support of the Ministry of Ecology, Sustainable Development and Energy (MEDDE in French). The program was restricted to pile foundations.

The SOLCYP project set out to improve our knowledge of the behavior of foundation piles subjected to cyclic stresses and to put forward procedures to take account of the effect of cycles when designing civil engineering or maritime structures.

A methodological and systematic approach was developed so as to reach a thorough understanding of the complex physical phenomena governing, firstly, the response of soils to cyclic loading and, secondly, the behavior of piles subjected to cyclic vertical or horizontal loads.

On these essentially experimental bases, effort was made to develop design procedures and engineering methods whose complexity of use is compatible with the nature of the works and the severity of the cyclic loading.

1.2.1. The ANR-SOLCYP program

The ANR section of the SOLCYP project started in June 2008. Initially intended to run for four years, it was extended for nine months and finished in March 2013. The administrative management of the ANR part of the project was handled by the Institut pour la recherche appliquée et l’expérimentation en génie civil (IREX – Institute for Applied Research and Experimentation in Civil Engineering) and its joint scientific managers were Alain Puech (Fugro GeoConsulting) and Jean Canou (École des Ponts ParisTech).

The project was run in collaboration by nine partners (not including IREX): six research laboratories and three industrial companies:

• – laboratories or research institutes:
  • - GeM (Ecole centrale de Nantes);
  • - IFSTTAR (ex LCPC);
  • - LGCgE (Lille University);
  • - LTDS (Ecole centrale de Lyon);
  • - Navier-Géotechnique (Ecole des Ponts ParisTech);
  • - 3S-R (Grenoble-Alpes University);
• – industrial organizations:
  • - EDF (engineering centers);
  • - Fugro GeoConsulting SAS (Nanterre);
  • - Saipem SA (St Quentin-en-Yvelines).

The scientific and technical content of the ANR-SOLCYP project hinges around five tasks:

• – experimental characterization of the monotonic and cyclic behavior of two reference soils: a clay and a sand;
• – experiments on the behavior of the soil–pile interfaces: soil–steel interfaces to characterize the behavior of driven piles and soil–concrete interfaces to characterize the behavior of bored piles;
• – calibration-chamber and centrifuge testing to see the overall response of the soil–pile system subjected to cyclic loading;
• – development of different numerical approaches to model the cyclic behavior of the piles;
• – proposal of procedures and computation methods for the design of piles subject to cyclic loading.

The ANR-SOLCYP final report, published in September 2013, gives an overview of the results obtained.

1.2.2. The national SOLCYP project

The national SOLCYP project was conducted in parallel and as an extension to the ANR-SOLCYP program over the 2009-2014 period.

PN-SOLCYP included a dozen actors in the civil engineering and energy sectors: BOTTE FONDATIONS, EDF, EDF-EN, FRANKI FONDATION, FUGRO, IHC, MENARD, SAIPEM, SOCOTEC, SOLETANCHE-BACHY, SUBSEA7, TERRASOL and TOTAL.

The labs and research institutes involved in the ANR-SOLCYP program were associated with PN-SOLCYP.

PN-SOLCYP was supported financially by the MEDDE and the Fédération nationale des travaux publics (FNTP – National Public Works Federation). It was certified by the ecoconstruction authority (Pays de la Loire) and received financial support from the region ...

Table of contents

• Cover
• Tabel of Contents
• Title
• Copyright
• Foreword
• Preface
• List of Symbols
• 1 SOLCYP Project
• 2 Scope and Field of Application of Recommendations
• 3 Cyclic Loading
• 4 Introduction to Cyclic Degradation
• 5 SOLCYP Design Strategy
• 6 Behavior of Piles Subject to Cyclic Axial Loading
• 7 Design of Piles Subjected to Cyclic Axial Loading
• 8 Behavior of Piles Subject to Cyclic Lateral Loading
• 9 Design of Piles Subject to Cyclic Lateral Loading
• 10 Determination of Cyclic Parameters for Pile Design
• 11 Recommendations for Testing Piles Under Cyclic Loading
• Index
• End User License Agreement