Software products
/
Geotechnical software GEO5 / Geotechnical analyses according to Eurocodes EN 1997 (EC7)
Geotechnical analyses according to Eurocodes EN 1997 (EC7)
(changed 3/2011)
Application of unified European standards (Eurocodes) is relevant to all structural designers and geotechnical engineers. It has impact on all steps of a structural design such as determination of loading, calculation of internal forces, dimensioning of structural members up to the entire analysis of a given geotechnical task. The following paragraphs are devoted to new terminology and approaches which appear in GEO5 programs starting with version 10.
Verification methodology – EN 1997-1 / Classical approach
GEO5 programs now allow for performing verification analysis according to EN 1997-1 standard. Nevertheless, it still maintains the possibility of using classical approaches such verification analyses based on limit states and factor of safety. Adopting EN 1997-1 standard, however, introduces certain new requirements to be addresses by the design engineers. The most important are:
- Selecting design approach
- Selecting or modifying partial factors of the analysis, respectively
- Actual analysis and verification
Selecting design approach and magnitudes of partial factors is mostly well described in National Annexes. The actual calculation and verification analysis is then quite similar to up to now used theories of limit states.
Analysis theory
Eurocode 1997-1 does not specify in detail the analysis methods – it only requires using generally accepted methods, which are verified and provide relevant results. Particular methods (e.g. determination of earth pressures, calculation of foundation or pile bearing capacity, stability analyses, etc) thus remain the same as in the previous versions of GEO5. In some cases, informative recommended methodologies based on to annexes to EN 1997-1 standard are implemented into programs.
National Annexes
National Annexes modify application of EN 1997-1 standard in individual countries. They determine the design approach for a given type of analysis and adjust magnitudes of partial factors (i.e. values generally recommended by EN 1997-1 standard). Our goal is to implement into individual programs all National Annexes – their current status, however, is not unified. In some countries the National Annexes bear already their final versions, others provide only their working. At present, National Annexes of 
Slovakia, 
Austria, 
Germany, 
Hungary, 
Portugal, 
Finland, 
Greece, 
Netherland, 
Great Britain and 
Slovenia are implemented.
Design approaches
The first important step when performing the analysis according to Eurocode is to selected the design approach. All design approaches adopt factors reducing loading (F-force). These factors multiply all forces entering the analysis.
- Design approach 1 further introduces reduction of parameters of soils (M – material). This approach requires performing the analysis twice for two design situations (reducing either F or M) and to choose the worst scenario.
- Design approach 2 introduces reduction of parameters of resistance (R - resistance), which reduces the resultant resistant forces (resistant forces, overturning moment…).
- Design approach 3 reduces parameters of soils (M) and load (F) together. It discriminates between structure loading (STR) and geotechnical loading (GEO). These have two different factors.
Partial factors
Programs allow for choosing or rather introducing partial factors for the selected design approach into the analysis. Programs contain standard factors based on EN and factors implemented according to National Annexes – all factors can be adjusted. Partial factors may also differ depending on the Design situation.
Design situations
Program introduces design situations in the sense of EN 1990 – permanent, transient, accidental and seismic. The design situation is selected always for a construction stage. It determines which set of partial factors will be used in the analysis.
Analyses of retaining structures
The actual analysis is considerably more complex compared to the classical analysis. Each force has different design factors for different failure modes depending, whether its acts favorably or unfavorably. For example, when considering translation and overturning the self-weight is assumed to act favorably whereas for the calculation of foundation bearing capacity it acts unfavorably (increases stress), but it can act even favorably (in case of large eccentricities). It is therefore necessary to carry out several analyses. For the user to control the analysis the program always displays the resultant combination of factors for individual failure modes.
Stability analyses
When running stability analysis all weights of individual slices are multiplied by a design factor depending, whether the resultant force on the slip surface acts favorably or unfavorably. In addition, soil parameters are reduced for design approaches 1 and 3 and the overall resistance on the slip surface for the design approach 2. The loading is reduced by a partial factor as a whole.
Analyses of foundations
In this case, self-weight of a structure and weight of soil above the spread footing, respectively, are multiplied by partial factors of loading. The assumed design loading must therefore be determined in accord with EN 1990 and EN 1991 standards. When considering the design approach 1 each loading case is analyzed separately with corresponding partial factors based on the specified type of design combination.
Analyses of sheeting and earth pressures
These programs consider the total earth pressure in the analysis and multiply individual components of pressure acting on a structure by partial factors. The basic assumption is that active pressure acts as an unfavorable loading whereas passive pressure acts favorably. Individual pressure diagrams are therefore multiplied by corresponding partial factors of loading.
Language: english
-
english
Company Fine develops structural engineering software with main focus on geotechnical software and structural engineering analyses.
-
magyar
A Fine építőmérnöki szoftvereket fejleszt, elsősorban statikai és geotechnikai programokat.
-
česky
Společnost Fine se zabývá vývojem stavebního software, zejména programů na statické výpočty, zakládání staveb a geotechniku.
-
ελληνικά
Η εταιρεία Fine αναπτύσσει λογισμικό για πολιτικούς μηχανικούς και ειδικά για γεωτεχνικά θέματα και δομοστατικά θέματα.
-
по-русски
Компания Fine занимается разработкой строительного программного обеспечения, особенно программ для расчета статики и геотехнических программ.
-
فارسی
شرکت Fine توسعه دهنده نرم افزار های مهندسی عمران با نگاه ویژه به نرم افزار های ژئوتکنیک و تحلیل های سازه ای مهندسی می باشد.
-
español
Fine es una compañía que desarrolla y suministra programas de ingeniería civil especializada en programas geotécnicos y de estructuras.
-
hrvatski
Fine je Češko podužeće koje razvija i dobavlja konstrukcijske i geotehničke programe. Trenutno tvrtka nudi više od 50 pojedinačnih programa za rješavanje zadataka za statiku, dizajn konstrukcija, temeljenja i geotehnike.