How to use Scage?
How to use Scage?IntroductionSteps to define a projectProjectMaterialsDefinition of phases and calculation envelopesNecessary steel sectionsDetailed calculationsULS checksSLS checksListingReinforced concretePrinting the calculation reportDocumentation
Introduction
Scage is a software dedicated to the structural analysis of reinforced concrete retaining walls in accordance with Eurocode 2.
Scage is a design tool for the internal balance of reinforced concrete retaining walls in accordance with Eurocode 2 (French and Belgian annexes) and the French national application standard of Eurocode 7 (NF P 94-282).
In particular, it makes it possible to calculate the necessary longitudinal steel sections for the ULS and SLS as well as the necessary transverse steel sections for the ULS from the results of the equilibrium calculation (K-Réa).
The calculation is carried out phase by phase in simple or compound bending, both at the ULS and SLS.
The phases are grouped by Envelope to facilitate the handling of the calculations to be performed.
Steps to define a project
Project
- General information
It is possible to define the name of the project and the calculation section. This information will be included when printing the calculation report.
It is possible to work with both metric and imperial units.
- Defining a calculation case (scenario)
Within a Scage project, it is possible to store several independent calculations in the form of Cases or Scenarios. The idea being to be able to define and compare several calculations performed, which allows to switch between them quickly. The interface also provides a system of preferred cases.
- Definition of geometry
The section is considered rectangular, defined from a calculation width and wall thickness.
The imported internal forces per unit of length will be multiplied by the input calculation width.
Materials
- Definition of materials
Concrete is characterized in terms of allowable stresses for each combination (the limitations required by NF P94-282 are also proposed). The inclination of the concrete rods must also be defined. The details of the calculations performed are provided under the Details button, with indications as to the chapter and source paragraph of the NF P94-282 standard. Their values are automatically calculated and can also be customized if the user wishes.
Steel is characterized by its characteristic strength, the branch of its constitutive law (horizontal or inclined), its modulus of elasticity or Young's modulus and its limit strains accessible from Details.
- Constitutive laws
The constitutive laws are represented to scale for the ultimate limit states. Graphics accept zoom and can be exported to the clipboard.
- Partial safety factors
The partial safety factors on the strength of concrete and steel have to be defined for each calculation combination. The coefficient of equivalence (ratio between the modulus of elasticity of steel and concrete) can also be set for SLS combinations.
Definition of phases and calculation envelopes
- Internal efforts
The internal forces of the wall must come from a soil-structure interaction calculation (ISS), for example from a K-Rea project or from an Excel file (find the model in the installation folder).
In the case of a K-Rea double wall project, it is possible to chose which wall (1 or 2) it should be imported.
In the case of an import from Excel, the solicitations must be provided to the SLS and ULS. Indeed, they are necessary for the proper functioning of the calculation.
When importing, all phases are displayed in the Unassigned Phases list. The user can then switch each phase into an envelope. It is also possible not to assign a phase to an envelope, which allows the freedom not to consider a phase in the calculation.
- Envelopes
It is possible to create as many envelopes as desired.
An envelope can contain one or more calculation phases.
In accordance with Eurocode 2, it is necessary to apply an offset to the bending moment diagrams to ensure that the longitudinal bars are loaded over their anchorage length. The offset value can be entered by the user or calculated automatically by the interface.
If the source file is modified during the Scage calculation, it is also possible to either import all phases again or only the values of the requests while keeping the same phase distribution within the envelopes.
- Internal efforts
The internal forces are presented in the form of two tabs: ULS (ultimate limit state) or SLS (serviceability limit state). The results can be displayed in graphical or tabular form.
The graphs are all titled and specify the unit of values displayed, as well as the minimum and maximum values. They allow zooming, both on the internal region and on the axes, as well as exporting to the clipboard.
Necessary steel sections
This section provides the necessary longitudinal and transverse steel sections for each envelope defined above.
- Envelopes
The calculation of reinforced concrete requires the definition of the position of the centre of gravity of the longitudinal bars in relation to the corresponding concrete fibre. At this point, this value is considered constant over the entire height of the wall.
The value of the offset value of the bending moment curves is recalled and can be modified again. It is also possible to reload internal requests if the source file has changed in the meantime.
It is necessary to define the situation to be considered at the ULS and SLS for each envelope, as well as the allowable steel stress at the SLS for each side of the wall and according to the depth. This stress can be defined according to the required limit crack opening (the coefficient is adjustable in the Settings tab).
The user is free to request either a simple or compound bending calculation for each calculation phase, which will have an impact on the required steel sections and the stresses generated at the SLS.
- Required steel sections
The necessary steel cross-sectional diagrams are shown according to the previous choices. They are presented in graphical or tabular form, both of which can be exported to the clipboard.
In accordance with Eurocode 2, transverse steel are only to be designed at the ULS.
Detailed calculations
This section provides access to calculation details at any level of calculation.
- Steel design
The user can choose the target diagram as well as the envelope and combination. A simple click on a curve allows you to locate and display a new line in the Results table.
- Results
The Results table is filled with all available data.
If the SLS combination is Quasi-Permanent, the equivalent diameter must be entered so that the crack opening calculation can be performed (exact method).
Details of the intermediate calculation parameters are displayed under the strain/stress graphs and the geometric section.
ULS checks
Once the cage is defined, this section provides the following results specific to the chosen reinforcement sections:
- Allowable bending moment at the ULS: it is calculated at each level from the strain diagram of the section at each phase (the axial force is kept equal to that applied)
- Allowable shear force at the ULS: it corresponds to the maximum shear force that the section can support. The values are proposed in graphical and tabular form.
SLS checks
Once the cage is defined, this section provides the following results specific to the chosen reinforcement sections:
- Allowable bending moment: it is calculated at each level from the practical steel sections while respecting the admissible limit stresses in concrete and steel (the axial force is kept equal to that applied).
- Steel stress: they correspond to the stresses generated by the computational stresses on the useful steel sections.
- Concrete stress: they correspond to the stresses generated by the computational stresses on the concrete section.
- Crack opening (only available for quasi-permanent situation): values of crack openings obtained by the exact method at each level as a function of the practical longitudinal reinforcement section, the working stress of the steel, the equivalent diameter and the average spacing of the longitudinal bars.
Listing
This section summarizes all the steel bars placed in the cage by specifying their type, diameter, dimensions, mandrel required for bending, length and mass.
The average diameter, the total mass of the cage and the steel ratio (weight of steel relative to the volume of concrete) are also calculated.
Reinforced concrete
This powerful calculation tool is proposed independently of the project carried out.
The objective is to allow the user to verify reinforced concrete calculations for a set of independent input data.
The details of the calculation are provided in the part of the manual dedicated to the compound bending calculation at the ULS and SLS as well as the calculation of transverse steel.
Printing the calculation report
Scage allows the printing of the report of the calculations performed while leaving the possibility to choose the content to be included. A dynamic print preview is provided on the interface.
The report can also be printed in PDF format, if a dedicated printer is available in the operating system.
Documentation
All Scage documentation is available in this category as .html files that can be opened in parallel with the interface via the default browser.
