Probabilistic Evaluations of Prescribed Safety Margins in Eurocode 7 for Spread Foundations

According to the design code Eurocode 7, analysis procedures require reaching a prescribed safety margin, based on the conditions of levelling design action and design resistance. Such semi-probabilistic procedures do not result in a consistent equivalent value of the Overall Factor of Safety (OFS), neither in individual analysis nor in different tasks in geotechnical engineering. Furthermore, the implementation of different calculation approaches in Eurocode 7 also does not guarantee an equal probability of the occurrence of a relevant limit state. A comparative analysis is conducted for an example of a centrically loaded spread foundation on homogenous, isotropic, and coarse-grained soil, according to procedures in Eurocode 7, Design Approach 3. An algorithm is developed to estimate failure probability, taking into consideration the relevant statistical characteristics of each calculation parameter. A significant influence of the statistical characteristics of the relevant sample is emphasized. The degree of required modification of the equivalent Overdesign Factor (ODF) and the Overall Factor of Safety (OFS), based on the criterion of the required reliability index β and failure probability pf , is quantified.

[1]  Norbert Jendzelovsky,et al.  Probabilistic Analysis of a Hospital Building Slab Foundation , 2020, Applied Sciences.

[2]  F. E. Sánchez,et al.  Probabilistic Method to Assess Model Uncertainty of Rigid Inclusion on a Granular Fill Supporting a Slab Foundation , 2020, Applied Sciences.

[3]  Mario Bačić,et al.  Application of neural networks for the reliability design of a tunnel in karst rock mass , 2020, Canadian Geotechnical Journal.

[4]  Lysandros Pantelidis,et al.  Reducing Statistical Uncertainty in Elastic Settlement Analysis of Shallow Foundations Relying on Targeted Field Investigation: A Random Field Approach , 2020, Geosciences.

[5]  Trevor L. L. Orr,et al.  Honing safety and reliability aspects for the second generation of Eurocode 7 , 2019, Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards.

[6]  R. R. Shakir.  Probabilistic-based analysis of a shallow square footing using Monte Carlo simulation , 2019, Engineering Science and Technology, an International Journal.

[7]  Anna Borowiec,et al.  Use of Probabilistic Analysis in Design of Shallow and Deep Foundations , 2019, IOP Conference Series: Materials Science and Engineering.

[8]  Krešo Ivandić,et al.  Analysis of the Engineering Judgement Influence on the Selection of Geotechnical Parameters Characteristic Values , 2018 .

[9]  Armin W. Stuedlein,et al.  Reliability-based serviceability limit state design for immediate settlement of spread footings on clay , 2015 .

[10]  T. H. Wu,et al.  Risk and reliability in geotechnical engineering , 2015 .

[11]  G. Dodagoudar,et al.  Finite element reliability analysis of shallow foundation settlements , 2015 .

[12]  Kok-Kwang Phoon,et al.  Reliability-based design and its complementary role to Eurocode 7 design approach , 2015 .

[13]  R. Chenari,et al.  Probabilistic Settlement Analysis of Shallow Foundations on Heterogeneous Soil Stratum with Anisotropic Correlation Structure , 2015 .

[14]  Jui-pin Wang,et al.  Estimating the standard deviation of soil properties with limited samples through the Bayesian approach , 2015, Bulletin of Engineering Geology and the Environment.

[15]  Abdul-Hamid Soubra,et al.  Reliability-Based Analysis and Design of Strip Footings against Bearing Capacity Failure , 2008 .

[16]  Andrew Harris,et al.  Decoding Eurocode 7 , 2006 .

[17]  Donald E. Myers,et al.  Reliability and Statistics in Geotechnical Engineering , 2005, Technometrics.

[18]  Serge Leroueil,et al.  Keynote Lecture - Geotechnical Engineering Of The Stability Of Natural Slopes, And Cuts And Fills In Soil , 2000 .

[19]  J. M. Duncan,et al.  Factors of Safety and Reliability in Geotechnical Engineering , 2000 .

[20]  K. Phoon,et al.  Characterization of Geotechnical Variability , 1999 .

[21]  Hid N. Grouni,et al.  Reliability based design in civil engineering , 1988 .

[22]  Peter Lumb,et al.  The Variability of Natural Soils , 1966 .

[23]  K. Phoon,et al.  Statistical determination of multivariate characteristic values for Eurocode 7 , 2020 .

[24]  Dimova Silvia,et al.  State of harmonised use of the Eurocodes , 2019 .

[25]  Trevor L. L. Orr,et al.  Recommended changes to Eurocode 7 , 2015 .

[26]  Kit Fai Ho.  Eurocode 7 and reliability : based design of earth retaining walls , 2015 .

[27]  G. Blöschl,et al.  Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards , 2008 .

[28]  R. Pöttler,et al.  Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards , 2007 .

[29]  H R Schneider,et al.  DEFINITION AND DETERMINATION OF CHARACTERISTIC SOIL PROPERTIES , 1999 .