In addition to our technical support (e.g. via chat), you’ll find resources on our website that may help you with your design using Dlubal Software.
Frequently Asked Questions (FAQ)
Customer Support 24/7
RF-/FOUNDATION Pro is a further development of the RF‑/FOUNDATION add-on module.
The main differences are as follows:
- Design according to Eurocode instead of DIN
- Additional foundation type "Block foundation with smooth bucket sides," see Figure 01:
- Input of a soil profile and settlement calculation, see Figure 02:
When entering a surface elastic foundation, you can set the nonlinearity for the spring stiffness in the direction of the local z‑axis. For example, "Failure if negative contact stress."
In the detail settings for the nonlinearity (a button to the right of the nonlinearity selection), you can select the "Friction in plane xy" option. Furthermore, you can also enter the friction coefficient.
This is possible in RF-/FOUNDATION Pro by defining the soil profile.In the input dialog box '1.1 General Data', you can find the button that opens the dialog box for defining the soil profile.In the 'Soil Profile' dialog box, you can then set the PGL altitude and PGL'.Important:The profile of the grade line must not be higher than the profile of the ground elevation.For a bucket foundation, PGL or PGL' refers to the upper edge of the bucket.
AnswerNo, this is not possible.The member elastic foundation is basically constant over the length of the member.If you want to enter a variable member foundation based on the height of the bored pile, you have to divide the bored pile into individual members and specify different constant foundations on the individual members. Thus, the linear distribution of a foundation can be approximately simulated.
The lap length design is performed according to DIN EN 1992‑1‑1, Section 8.7.3 or Section 10.9.6.3 for block and bucket foundations with the profiled bucket surface.You can optionally deactivate the design by using the [Details ...] button.An example of the lap length calculation for a bucket foundation can be found in the RF‑/FOUNDATION Pro manual, which you can download using the following link, or open it directly in the add-on module by pressing the [F1] key.
This is possible in RFEM in an indirect way.The soil pressure, from which the bending moment is determined for the design by using the integration, can be applied as an "external load" in the RFEM initial model.Distribution of Compressive Stress in RF-/FOUNDATION ProThis compressive stress can be applied as a "Free Surface Load" to an equivalent structural system in RFEM.In this case, the equivalent structural system is a rigid surface. The size of the surface depends on the position of the design section set in RF‑/FOUNDATION Pro. In this case, it is necessary to set "In Column Center."With this equivalent structure, it is possible to recalculate the "moment from the distribution of compression stress" determined in RF‑/FOUNDATION Pro.You can download the example described above using the link below and open it in RFEM 5.
AnswerThe theoretical approaches for this can be found in "Leonhardt, Fritz. (1977). Vorlesungen über Massivbau, Drittel Teil, (3rd ed.). Berlin [etc.]: Springer."Special attention must be paid to Chapter 16.3 "Single Foundations for Columns."
AnswerBoth RFEM and RSTAB provide a suitable solution. In addition to Eurocode 2, the international standards, such as ACI 318, CSA A23.3, SIA 262, or GB 50010, are also available for the design in both programs.
With the add-on modules for designing columns or foundations, or for punching shear designs, it is possible to quickly and reliably calculate the structural components.
Main Programs RFEM or RSTABThe main programs RFEM or RSTAB are used to define structures, materials, and actions.
For reinforced concrete structures, RFEM is clearly the first choice as it allows you to also create structural systems consisting of plates, walls and shells in addition to spatial frame structures. RFEM is the more diverse variant as it can be equipped and extended with the corresponding add-on modules for all materials and designs.
- Eurocode 2 (EN 1992-1-1)
- SIA 262
- ACI 318
- CSA A23.3
- GB 50010
- RF-/CONCRETE Columns
Reinforced concrete design according to the model column method or the nominal curvature method
- RF-PUNCH Pro
Punching shear designs of surfaces
- RF-/FOUNDATION Pro
Design of single, bucket and block foundations
- RF-CONCRETE Deflect (RFEM)
Analytical deformation analysis
- RF-CONCRETE NL
Realistic deformation analysis of surfaces and members
Dynamic AnalysisIf it is necessary to perform seismic analysis or vibration designs of a building, the RF‑/DYNAM Pro add-on modules provide special tools for determining natural frequencies and mode shapes, for an analysis of forced vibrations, a generation of equivalent loads, or for a nonlinear time history analysis.If you have any question about the Dlubal Software programs, please do not hesitate to contact the sales department.
This discrepancy is often caused by changing DIN 1054 to EN 1997.In the "old" DIN 1054, the design was performed by using the characteristic values on the action side and the allowable stress on the resistance side. The actions were used without partial factors and compared with certain allowable stress. In this case, the "eta" resistance was completely included in the allowable stress.In the predecessor module of RF‑FOUNDATION Pro, which performed the calculations according to DIN 1054, there was a special tab "Ground Failure Analysis (Service Loads)" for this purpose.In the Eurocode, the ground failure design is performed in a different way.Here, a partial factor is applied to the action and the resistance side. Thus, the loading is increased by the factor of 1.35 or 1.5, and the resistance is reduced by the factor of 1.4.With regard to the "old standard," the "eta" resistance is completely included in the "allowable stress sigma_all."Under the Downloads link below, you can find a model file for RFEM or RSTAB, which clarifies the problem in RF‑/FOUNDATION or RF‑/FOUNDATION Pro. Here, the design has not been performed by using the user-defined entry of the soil pressure, but using the allowable stresses from the standard case tables. There should be the same soil with approximately the same foundation dimensions resulting or the Eurocode and for the old standard.The following assumptions for the foundation have been made in both add-on modules:
When using the all. soil resistance according to DIN EN 1997‑1 from the standard case tables, the factor of 1.4 is already included. The base values Sigma‑R,d(B) of the soil resistance also differ by the factor of 1.4 compared to the allowable soil pressure "sigma_all" (DIN 1054).Results of the comparison:Ground failure design according to DIN 1054 in RF‑/FOUNDATION (old):Ground failure design according to EN 1997‑1 in RF‑/FOUNDATION Pro:In spite of different input values, the results from DIN 1054 and EN 1997‑1 are comparable.If you want to recalculate the foundation in RF‑/FOUNDATION Pro, which has already been designed with RF‑/FOUNDATION (old), you would have to apply twice the soil pressure Sigma_R,k:Sigma_R,k (input in RF‑/FOUNDATION Pro) = 1.40 (partial factor for ground failure) x 1.35 (resistance on the load side in the example) x Sigma_all (from RF‑/FOUNDATION (old)).In the attached file, this has been done in CA2 in both add‑on modules. In this case, the allowable soil pressure has been entered as 4,595 kip/ft² in RF‑/FOUNDATION. In RF‑/FOUNDATION Pro, 8,688 kip/ft² has been entered.
- Cohesive soil
- Pure silt - UL
- Stiff consistency
- Embedment depth of the foundation t = 4.92 ft
AnswerYes, it is possible.You can enter a pile foundation to a structural model in RFEM.Thus, the effects of the foundation stiffness on the actual structure can be simulated very well.However, please note that Dlubal Software currently provides no solutions for the design of pile foundations.This also means that the pile resistance must be known to the user in advance. It cannot be calculated in RFEM, for example, by defining a soil structure.The piles can be designed as beams by using a circular cross-section, for example.The resistance of the piles can be modeled by entering a member elastic foundation or a nodal support at the pile end.Subsequently, the design of the beam can be performed in the RF‑CONCRETE Members add-on module. However, please note that RF‑CONCRETE Members only covers the standards relevant for the structures above ground level. That is, for example, DIN EN 1992‑1‑1.
Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.
Wind Simulation & Wind Load Generation
With the stand-alone program RWIND Simulation, wind flows around simple or complex structures can be simulated by means of a digital wind tunnel.
The generated wind loads acting on these objects can be imported to RFEM or RSTAB.
“Thank you for the valuable information.
I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. I have used a lot of software with a support contract in the field of structural analysis, but your support is by far the best. ”