scholarly journals Modified, Reliability-Based Robust Geotechnical Design Method, in Accordance with Eurocode 7

2021 ◽  
Vol 11 (18) ◽  
pp. 8423
Author(s):  
Filip Dodigović ◽  
Krešo Ivandić ◽  
Meho-Saša Kovačević ◽  
Božo Soldo
Keyword(s):  
Reliability Index ◽  
Design Method ◽  
System Response ◽  
Reliability Based Design ◽  
Eurocode 7 ◽  
Robustness Measure ◽  
Response Variance ◽  
Feasibility Robustness ◽  
Geotechnical Design ◽  
User Friendly

In this paper a modification of the reliability-based robust geotechnical design (RGD) method is proposed. The intention of the proposed modifications is to simplify the method, make it less computationally expensive, and harmonise of the results with Eurocode 7. The complexity of the RGD method mainly stems from the calculation of the design’s robustness measure, which is the feasibility robustness index (ββ). Due to this fact, the replacing of the existing robustness measure with a generalised reliability index (β) is considered. It was demonstrated that β fits into the robustness concept, and is traditionally used as a construction reliability measure, making it intuitive and “user friendly”. It is proposed to conduct a sensitivity analysis using Soboli indices, with the aim of freezing the variables whose contribution to the system response variance is negligible, which will further simplify the method. By changing the robustness measure, the number of the required reliability analyses is significantly decreased. Further reduction is achieved by conducting analyses only for the designs chosen in the scope of the genetic algorithm. The original RGD method is used as an extension of traditional reliability-based design. By applying the proposed modifications, the RGD method can be used as an alternative to the classic and reliability-based design method.

scholarly journals German Proposals for the Revision of Eurocode 7 “Geotechnical design”

2016 ◽  
Author(s):  
Markus Braun ◽  
Bernd Schuppener ◽  
Thomas Richter ◽  
Franz Ruppert ◽  
Martin Ziegler
Keyword(s):  
Human Error ◽  
First Generation ◽  
Safety Factors ◽  
Limit States ◽  
Eurocode 7 ◽  
Geotechnical Design ◽  
Partial Safety Factors ◽  
Structural Engineers ◽  
User Friendly ◽  
New Formula

After implementing the Eurocodes, concerns were raised that the set of rules and regulations is not suitable for the designer’s day-to-day use. The first generation of Eurocodes consists of 58 codes with more than 5,200 pages. Moreover, practitioners have to cope with national supplementary codes. As a result, an “Initiative on Improving the Practicability of Technical Rules for Building Constructions” (PRB) was established by the German construction industry and associations of structural engineers in 2011. As part of the initiative, a Project Group for Geotechnical Design was established alongside groups for the other Eurocodes, with the aim of streamlining Eurocode 7 and reducing the number of design approaches and partial safety factors. The paper will analyse the shortcomings of the two parts of Eurocode 7 and present a concept for a more concise and user-friendly code. Furthermore, comparative calculations have been performed for standard geotechnical design applications to investigate the potential for European harmonization in geotechnical design. The results are described and it is shown how they can be incorporated in the revision of EC 7. Moreover, a new formula for verifying geotechnical ultimate limit states is presented which formally covers all design approaches and also enables other parameters such as consequence classes, human error etc. to be incorporated by applying different multiplicative partial safety factors.

Gradient-based design robustness measure for robust geotechnical design

2014 ◽  
Vol 51 (11) ◽  
pp. 1331-1342 ◽  
Author(s):  
Wenping Gong ◽  
Sara Khoshnevisan ◽  
C. Hsein Juang
Keyword(s):  
Design Optimization ◽  
Robust Design ◽  
Cost Efficiency ◽  
Robust Design Optimization ◽  
System Response ◽  
Robustness Measure ◽  
Gradient Based ◽  
Geotechnical Design ◽  
Safety Constraint ◽  
Noise Factors

This paper presents a gradient-based robustness measure for robust geotechnical design (RGD) that considers safety, design robustness, and cost efficiency simultaneously. In the context of robust design, a design is deemed robust if the system response of concern is insensitive, to a certain degree, to the variation of noise factors (i.e., uncertain geotechnical parameters, loading parameters, construction variation, and model biases or errors). The key to a robust design is a quantifiable robustness measure with which the robust design optimization can be effectively and efficiently implemented. Based on the developed gradient-based robustness measure, a robust design optimization framework is proposed. In this framework, the design (safety) constraint is analyzed using advanced first-order second-moment (AFOSM) method, considering the variation in the noise factors. The design robustness, in terms of sensitivity index (SI), is evaluated using the normalized gradient of the system response to the noise factors, which can be efficiently computed from the by-product of AFOSM analysis. Within the proposed framework, robust design optimization is performed with two objectives, design robustness and cost efficiency, while the design (safety) constraint is satisfied by meeting a target reliability index. Generally, cost efficiency and design robustness are conflicting objectives and the robust design optimization yields a Pareto front, which reveals a tradeoff between the two objectives. Through an illustrative example of a shallow foundation design, the effectiveness and significance of this new robust design approach is demonstrated.

Evaluation of the Uncertainties Related to the Geotechnical Design Method and Its Consideration in Reliability Based Design

Geo-Risk 2017 ◽  
2017 ◽  
Author(s):  
Kerstin Lesny ◽  
Sami Akbas ◽  
Witold Bogusz ◽  
Sébastien Burlon ◽  
Giovanna Vessia ◽  
...  
Keyword(s):  
Design Method ◽  
Reliability Based Design ◽  
Geotechnical Design

scholarly journals Comparative Analysis of Kazakhstani and European Design Specifications: Raft Foundation, Pile Foundation, and Piled Raft Foundation

2021 ◽  
Vol 11 (7) ◽  
pp. 3099
Author(s):  
Assel Zhanabayeva ◽  
Nazerke Sagidullina ◽  
Jong Kim ◽  
Alfrendo Satyanaga ◽  
Deuckhang Lee ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
International Standards ◽  
Piled Raft ◽  
Codes Of Practice ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Eurocode 7 ◽  
Elastic Settlement ◽  
Geotechnical Design ◽  
The Difference

The introduction of Eurocode in Kazakhstan allows for the application of modern technological innovations and the elimination of technical barriers for the realization of international projects. It is significant to study the international standards and design requirements provided in Eurocode. This study presents a comparative analysis of Kazakhstani and European approaches for the geotechnical design of foundations and provides the design methods in the considered codes of practice. Three different types of foundations (i.e., raft, pile, and piled raft foundations) were designed following SP RK 5.01-102-2013—Foundations of buildings and structures, SP RK 5.01-103-2013—Pile foundations, and Eurocode 7: Geotechnical design for the Nur-Sultan soil profile. For all three types of foundations, the calculated results of bearing resistance and elastic settlement showed the conservativeness of Eurocode over SNiP-based Kazakhstani building regulations, as the values of bearing resistance and elastic settlement adhering to Kazakhstani code exceeded the Eurocode values. The difference between the obtained results can be explained by the application of higher values of partial safety factors by Eurocode 7. Sensitivity analysis of the bearing resistance on foundation parameters (i.e., raft foundation width and pile length) for the Kazakhstani and European approaches was performed to support the conclusions of the study.

scholarly journals Distributed Energy-Resource Design Method to Improve Energy Security in Critical Facilities

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2773
Author(s):  
Petros Siritoglou ◽  
Giovanna Oriti ◽  
Douglas L. Van Bossuyt
Keyword(s):  
Energy Security ◽  
Design Method ◽  
Storage System ◽  
Energy Resource ◽  
Energy Storage System ◽  
Distributed Energy ◽  
Distributed Energy Resource ◽  
Critical Facilities ◽  
Commercial Off The Shelf ◽  
User Friendly

This paper presents a user-friendly design method for accurately sizing the distributed energy resources of a stand-alone microgrid to meet the critical load demands of a military, commercial, industrial, or residential facility when utility power is not available. The microgrid combines renewable resources such as photovoltaics (PV) with an energy-storage system to increase energy security for facilities with critical loads. The design method’s novelty complies with IEEE Standards 1562 and 1013, and addresses resilience, which is not taken into account in existing design methods. Several case studies simulated with a physics-based model validate the proposed design method and demonstrate how resilience can be included in the design process. Additionally, the design and the simulations were validated by 24 h laboratory experiments conducted on a microgrid assembled using commercial off-the-shelf components.

Barrier Function Method in Reliability Based Design Optimization

2005 ◽  
Vol 297-300 ◽  
pp. 1882-1887
Author(s):  
Tae Hee Lee ◽  
Jung Hun Yoo
Keyword(s):  
Design Optimization ◽  
Barrier Function ◽  
Reliability Index ◽  
Feasible Solution ◽  
Reliability Based Design Optimization ◽  
User Requirement ◽  
Mean Values ◽  
Reliability Based Design ◽  
Design Variables ◽  
Reliability Method

In practical design applications, most design variables such as thickness, diameter and material properties are not deterministic but stochastic numbers that can be represented by their mean values with variances because of various uncertainties. When the uncertainties related with design variables and manufacturing process are considered in engineering design, the specified reliability of the design can be achieved by using the so-called reliability based design optimization. Reliability based design optimization takes into account the uncertainties in the design in order to meet the user requirement of the specified reliability while seeking optimal solution. Reliability based design optimization of a real system becomes now an emerging technique to achieve reliability, robustness and safety of the design. It is, however, well known that reliability based design optimization can often have so multiple local optima that it cannot converge into the specified reliability. To overcome this difficulty, barrier function approach in reliability based design optimization is proposed in this research and feasible solution with specified reliability index is always provided if a feasible solution is available. To illustrate the proposed formulation, reliability based design optimization of a bracket design is performed. Advanced mean value method and first order reliability method are employed for reliability analysis and their optimization results are compared with reliability index approach based on the accuracy and efficiency.

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