Reliability Based Investigation on the Choice of Characteristic Soil Properties
By using partial factors of safety, uncertainties due to the inherent variability of the soil properties and loads are taken into account in the geotechnical design process. According to the reliability index concept in Eurocode-0 in conjunction with Eurocode-7 a minimum safety level of β = 3.8 for reliability class RC2 shall be established. The reliability of the system depends heavily on the choice of the prespecified safety factor and the choice of the characteristic soil properties. The safety factors stated in the standards are mainly based on experience. However, no general accepted method for the calculation of a characteristic value within the current design practice exists. In this study, a laterally loaded monopile is investigated and the influence of the chosen quantile values of the deterministic system, calculated with p-y springs, will be presented. Monopiles are the most common foundation concepts for offshore wind energy converters. Based on the calculations for non-cohesive soils, a recommendation for an appropriate quantile value for the necessary safety level according to the standards for a deterministic design is given.
[1] Phoon, K.K., Reliability-based design of foundations for transmission line structures. A PhD dissertation submitted to Cornell University. 1995.
[2] Eurocode 7, DIN EN 1997. Eurocode: Geotechnical design. 2010.
[3] Wang, Y., “Selection of characteristic values for rock and soil properties using Bayesian statistics and prior knowledge”. Working Group on “Discussion of statistical/reliability methods for Eurocodes”. 2017.
[4] Schneider, H.R., Schneider, M.A., “Modern Geotechnical Design Codes of Practice (Implementation, Application and Development)”, Chapter: Dealing with uncertainties in EC7 with emphasis on determination of characteristic soil properties, Publisher: IOS Press, pp.87-101. 2012.
[5] Simpson, B., “Eurocode 7-Fundamental issues and some implications for users”, Keynote Lecture, in NGM 2012, Proc. DGF Bulletin 27, Vol.1, pp. 29-52, 2012.
[6] Orr, T.L.L., “Defining and selecting characteristic values of geotechnical parameters for design to Eurocode 7. Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards”, 11:1, 103.115. 2017.
[7] Thieken, K., Achmus, M. and Lemke, K., “A new static p-y approach for piles with arbitrary dimensions in sand”, Geotechnik 38 (4), pp. 267-288. 2015.
[8] Bucher, C., “Asymptotic sampling for high-.dimensional reliability analysis”. Probabilistic Engineering Mechanics 24. pp 504-510. 2009.
[9] Phoon, K.K. and Kulhawy, F.H., “Characterisation of model uncertainties for laterally loaded rigid drilled shafts”. Géotechnique 55, No 1. pp. 45-54. 2005.
[10] American Petroleum Institute, “Geotechnical and Foundation Design Considerations”, API Recommended Practice 2 GEO, First Edition, April 2011, Addendum 1, October 2014.
[11] Reese, L. C., Cox, W. R. & Coop, F. D., Analysis of laterally loaded piles in sand. Proc. 6th Offshore Technology Conf., Houston 2, 473–483. 1974.
[12] Murchison, J. M., O’Neill, M. W.: Evaluation of p-y-Relationship in Cohesionless Soils, Analysis and Design of Pile Foundations (ASCE), 1984, pp. 174–191.
[13] DIN 4085:2017-08: Baugrund - Berechnung des Erddrucks (in German)
[14] Terceros, M., Schmoor, K.A., Thieken, K., IGtHPile Software & calculations examples, www.igth.uni-hannover.de/downloads. 2015.
[15] DIN 1054:2010-12, Deutsches Institut für Normung e.V. (DIN), DIN 1054:2010-02: Baugrund - Sicherheitsnachweise im Erd- und Grundbau - Ergänzende Regelungen zur DIN EN 1997-1, 2010 (in German). 2010.
[16] Thieken, K. Achmus, M., Schmoor, K.A., “On the ultimate limit state design proof for laterally loaded piles”. Geotechnik 37 No 1. Ernst & Sohn Verlag. 2014.
[17] Holicky M. and Markova, J., “Code calibration allowing for reliability differentiation and production quality”. Applications of Statistics and Probability in Civil Engineering. 2007.
[18] Phoon, K.K. and Kulhawy, F.H., “Characterization of geotechnical variability”. Canadian Geotechnical Journal 36, pp. 612-624. 1999.
[19] Schmoor K.A., „Probabilistische Analyse zum Sicherheitsniveau von Offshore-Gründungspfählen“. PhD Thesis. Institute for Geotechnical Engineering Hannover, Leibniz University of Hannover (in German). 2016.
[20] Det Norske Veritas-DNVGL, “Support structures for wind turbines DNVGL-ST-0126”. 2016.
[21] Eurocode 0, DIN EN 1990. Eurocode: Basis of structural design. 2010.
[22] Phoon, K.K., “Reliability-based design in geotechnical engineering-Computations and applications”. 2008.
[23] Saathoff, J.E., Schmoor, K.A., Achmus, M., Terceros, M., Investigation on the reliability of laterally loaded monopile foundations. Proceedings of the 29th European Safety and Reliability Conference. 2019. (to be published).
[24] Empfehlungen des Arbeitskreises "Baugrunddynamik"-EAB. 2. Edition. DGGT. Ernst & Sohn Verlag. (2018) (in German).
[25] Thieken, K., “Geotechnical Design Aspects of Foundations for Offshore Wind Energy Converters”. PhD Thesis, Institute for Geotechnical Engineering Hannover, Leibniz University of Hannover. 2015.
[26] Dithinde, M., Characterisation of Model Uncertainty for Reliability-Based Design of Pile Foundations. PhD Dissertation submitted to University of Stellenbosch, 2007.
[27] Orr, T.L.L, Matsui, K. Day, P. Survey of geotechnical investigation methods and determination of parameter values. Proc. Of Foundation Design Codes and Soil Investigation in View of International Harmonization and Performance-Based Design. Japan. pp. 227-235. (2002).
[1] Phoon, K.K., Reliability-based design of foundations for transmission line structures. A PhD dissertation submitted to Cornell University. 1995.
[2] Eurocode 7, DIN EN 1997. Eurocode: Geotechnical design. 2010.
[3] Wang, Y., “Selection of characteristic values for rock and soil properties using Bayesian statistics and prior knowledge”. Working Group on “Discussion of statistical/reliability methods for Eurocodes”. 2017.
[4] Schneider, H.R., Schneider, M.A., “Modern Geotechnical Design Codes of Practice (Implementation, Application and Development)”, Chapter: Dealing with uncertainties in EC7 with emphasis on determination of characteristic soil properties, Publisher: IOS Press, pp.87-101. 2012.
[5] Simpson, B., “Eurocode 7-Fundamental issues and some implications for users”, Keynote Lecture, in NGM 2012, Proc. DGF Bulletin 27, Vol.1, pp. 29-52, 2012.
[6] Orr, T.L.L., “Defining and selecting characteristic values of geotechnical parameters for design to Eurocode 7. Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards”, 11:1, 103.115. 2017.
[7] Thieken, K., Achmus, M. and Lemke, K., “A new static p-y approach for piles with arbitrary dimensions in sand”, Geotechnik 38 (4), pp. 267-288. 2015.
[8] Bucher, C., “Asymptotic sampling for high-.dimensional reliability analysis”. Probabilistic Engineering Mechanics 24. pp 504-510. 2009.
[9] Phoon, K.K. and Kulhawy, F.H., “Characterisation of model uncertainties for laterally loaded rigid drilled shafts”. Géotechnique 55, No 1. pp. 45-54. 2005.
[10] American Petroleum Institute, “Geotechnical and Foundation Design Considerations”, API Recommended Practice 2 GEO, First Edition, April 2011, Addendum 1, October 2014.
[11] Reese, L. C., Cox, W. R. & Coop, F. D., Analysis of laterally loaded piles in sand. Proc. 6th Offshore Technology Conf., Houston 2, 473–483. 1974.
[12] Murchison, J. M., O’Neill, M. W.: Evaluation of p-y-Relationship in Cohesionless Soils, Analysis and Design of Pile Foundations (ASCE), 1984, pp. 174–191.
[13] DIN 4085:2017-08: Baugrund - Berechnung des Erddrucks (in German)
[14] Terceros, M., Schmoor, K.A., Thieken, K., IGtHPile Software & calculations examples, www.igth.uni-hannover.de/downloads. 2015.
[15] DIN 1054:2010-12, Deutsches Institut für Normung e.V. (DIN), DIN 1054:2010-02: Baugrund - Sicherheitsnachweise im Erd- und Grundbau - Ergänzende Regelungen zur DIN EN 1997-1, 2010 (in German). 2010.
[16] Thieken, K. Achmus, M., Schmoor, K.A., “On the ultimate limit state design proof for laterally loaded piles”. Geotechnik 37 No 1. Ernst & Sohn Verlag. 2014.
[17] Holicky M. and Markova, J., “Code calibration allowing for reliability differentiation and production quality”. Applications of Statistics and Probability in Civil Engineering. 2007.
[18] Phoon, K.K. and Kulhawy, F.H., “Characterization of geotechnical variability”. Canadian Geotechnical Journal 36, pp. 612-624. 1999.
[19] Schmoor K.A., „Probabilistische Analyse zum Sicherheitsniveau von Offshore-Gründungspfählen“. PhD Thesis. Institute for Geotechnical Engineering Hannover, Leibniz University of Hannover (in German). 2016.
[20] Det Norske Veritas-DNVGL, “Support structures for wind turbines DNVGL-ST-0126”. 2016.
[21] Eurocode 0, DIN EN 1990. Eurocode: Basis of structural design. 2010.
[22] Phoon, K.K., “Reliability-based design in geotechnical engineering-Computations and applications”. 2008.
[23] Saathoff, J.E., Schmoor, K.A., Achmus, M., Terceros, M., Investigation on the reliability of laterally loaded monopile foundations. Proceedings of the 29th European Safety and Reliability Conference. 2019. (to be published).
[24] Empfehlungen des Arbeitskreises "Baugrunddynamik"-EAB. 2. Edition. DGGT. Ernst & Sohn Verlag. (2018) (in German).
[25] Thieken, K., “Geotechnical Design Aspects of Foundations for Offshore Wind Energy Converters”. PhD Thesis, Institute for Geotechnical Engineering Hannover, Leibniz University of Hannover. 2015.
[26] Dithinde, M., Characterisation of Model Uncertainty for Reliability-Based Design of Pile Foundations. PhD Dissertation submitted to University of Stellenbosch, 2007.
[27] Orr, T.L.L, Matsui, K. Day, P. Survey of geotechnical investigation methods and determination of parameter values. Proc. Of Foundation Design Codes and Soil Investigation in View of International Harmonization and Performance-Based Design. Japan. pp. 227-235. (2002).
@article{"International Journal of Architectural, Civil and Construction Sciences:79191", author = "Jann-Eike Saathoff and Kirill Alexander Schmoor and Martin Achmus and Mauricio Terceros", title = "Reliability Based Investigation on the Choice of Characteristic Soil Properties", abstract = "By using partial factors of safety, uncertainties due to the inherent variability of the soil properties and loads are taken into account in the geotechnical design process. According to the reliability index concept in Eurocode-0 in conjunction with Eurocode-7 a minimum safety level of β = 3.8 for reliability class RC2 shall be established. The reliability of the system depends heavily on the choice of the prespecified safety factor and the choice of the characteristic soil properties. The safety factors stated in the standards are mainly based on experience. However, no general accepted method for the calculation of a characteristic value within the current design practice exists. In this study, a laterally loaded monopile is investigated and the influence of the chosen quantile values of the deterministic system, calculated with p-y springs, will be presented. Monopiles are the most common foundation concepts for offshore wind energy converters. Based on the calculations for non-cohesive soils, a recommendation for an appropriate quantile value for the necessary safety level according to the standards for a deterministic design is given.
", keywords = "Asymptotic sampling, characteristic value, monopile foundation, probabilistic design, quantile values. ", volume = "13", number = "10", pages = "629-9", }
