Geotechnical design is a product of local history, engineering practice, availability of construction materials and, of course, the geology of each site. All of these factors vary from region to region, which is why a standard recipe for developing geotechnical codes of practice does not exist.
Geotechnical design is a product of local history, engineering practice, availability of construction materials and, of course, the geology of each site. All of these factors vary from region to region, which is why a standard recipe for developing geotechnical codes of practice does not exist. It is probably fair to say that the differences in geotechnical design codes worldwide are much larger than exist between steel or concrete design codes. Steel and concrete are quality controlled materials and the uncertainty in their engineering behaviour is very similar from region to region. Thus, concrete and steel design codes have been able to take advantage of worldwide research efforts in their calibration over the decades.
Modern geotechnical design codes are generally striving towards a similar harmonisation, both with their counterpart structural design codes and between regional geotechnical codes. However, harmonising geotechnical design codes is not an easy task. An excellent example of the challenges faced in harmonisation is presented by Eurocode 7. Although aiming to create common terms of reference, Eurocode 7 still required several design approaches to accommodate the needs of all member states, along with national annexes enabling each member state to define their own set of safety factors. Why was this diversity in design approaches necessary? And what do code developers have in mind when they make their choices in adopting a design approach or set of safety factors? Some answers to these questions will be given in this book.
The impetus for this publication started with an international workshop on Safety Concepts and Calibration of Partial Factors in European and North American Codes of Practice, which was held on November 30 to December 1, 2011 at Delft University of Technology, the Netherlands. The aim of the workshop was to exchange ex perience and transfer knowledge between code developers, practitioners, and researchers on code development, safety concepts and the calibration of partial factors in modern geotechnical codes of practice. The attendees, who were leading authorities from Europe and North America, provided interesting and valuable insights into the development of their own national codes. This workshop led to the idea of collecting contributions from geotechnical code developers worldwide into a single book, providing a resource that can be referred to as a guide in the years to come.
The papers collected in this book are organised into three sections: Code Implementation describes choices relating to safety concepts, target reliabilities, and design approaches; Code Application addresses their application to specific geotechnical problems; and Code Development includes papers discussing directions for future developments.
The editors would like to acknowledge the support of the following committees who have substantially contributed to and supported this publication: the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Technical Committee for Safety and Serviceability in Geotechnical Design (TC 205), Technical Committee for Engineering Practice of Risk Assessment and Management (TC 304), and the Comité Européen de Normalisation (CEN) Technical Committee for Structural Eurocodes (TC250).
- Code Implementation
- Implementation and evolution of Eurocode 7
- Harmonisation of Anchor Design within Eurocode
- Eurocode 7 and Polish Practice: Implementation of Eurocode 7 in Poland
- An Explanation of Characteristic Values of Soil Properties in Eurocode 7
- Implementation of Eurocode 7 in German Geotechnical Design Practice
- Implementation of Eurocode 7 in French practice by means of national additional standards
- Implementing Eurocode 7 to achieve reliable geotechnical designs
- Dealing with uncertainties in EC7 with emphasis on determination of characteristic soil properties
- The Safety Concept in German Geotechnical Design Codes
- British choices of geotechnical design approach and partial factors for EC7
- Dutch approach to Geotechnical design by Eurocode 7, based on probabilistic analyses
- Code Application
- Limit state design of the foundations of concrete gravity dams - A case study
- Using Numerical Analysis with Geotechnical Design Codes
- Influence of Ground Water Level on Shallow Foundation Design. Application of EC7 Probabilistic and Deterministic Methods
- Reliability Based Design of Drilled Shafts: LRFD and Performance Based Design
- Application of Computational Limit Analysis in Ultimate Limit State Design
- Probabilistic assignment of design strength for sands from in-situ testing data
- Experiences with Limit State Approach for Design of Spread Foundations in the Czech Republic
- Code Development
- AASHTO Geotechnical Design Specification Development in the USA
- Lessons learned from LRFD calibration of reinforced soil wall structures
- Geotechnical Design Code Development in Canada
- Can We Do Better Than the Constant Partial Factor Design Format?
- Target Reliabilities and Partial Factors for Flood Defenses in the Netherlands