D-Foundations follows the Eurocode 7 and the Dutch and Belgium National Annexes. First D-Foundations is used to create and optimize a design. In this process, automatic optimization options assist the user to efficiently create and fine-tune a design. Once the design is finished D-Foundations can perform a design code check resulting in a detailed report for the given situation. The ability to overrule and redefine various design code parameters allows D-Foundations to be used by engineers for specialized calculations using user defined foundation types and factors. Some specific features in D-Foundations are:
- Soil data definition
D-Foundations requires input data from Cone Penetration Tests (CPT). Importing CPT data is possible in several formats, including the Geotechnical Exchange Format (GEF) and the format used by the Database Ondergrond Vlaanderen (DOV). Besides using GEF-files, CPT’s can be imported directly from the Dutch DINO database by TNO. The automatic CPT interpretation tool provides soil-type dependent proposals, including design code based parameter proposals.
- Preliminary design of piles
D-Foundations provides simultaneous results of bearing capacity and required length for different pile types and different soil conditions.
- Pile group interaction
In calculations, the effect of pile group interaction on settlement is included as well as on bearing capacity for the selected pile type and pile plan.
- Design of shallow foundations
Foundation dimensions can be optimized. In addition, the required width for strip foundations and the capacity and stability of shallow foundations can be checked.
- Code-based verification
A complete verification report can be generated in Dutch and English.
- Standard parameters
All standard parameters provided by Eurocode 7 (such as soil parameters and pile type parameters) are incorporated within D-Foundations for easy and fast selection.
D-Foundations requires the input of digitized CPT’s which are now widely available. For a full 3D analysis of piles and pile groups including pile interaction under vertical as well as horizontal loading, Deltares offers the D-Pile Group software. D-Pile Group follows the American Petroleum Institute (API) standard.
How to obtain D-Foundations
This version is available if you have purchased a Service package. You can order a Service package via our Software sales Service team (email@example.com). The software can be downloaded via our Download portal. You don’t need a license file to do this. You can use the software in Demo mode without a license file.
By purchasing a Service package you will receive a license file to unlock full functionality (according to purchased package). Our Software sales Service team will provide you with instructions on how to get the software working with a license file.
You can also use our Geotechnical software products via the internet (Software as a Service – SaaS), on subscription basis. For more information, please see Online Geotechnical Software.
D-Foundations – Bearing Piles(EC7-B)
This module is similar to the base module of D-Foundations for bearing piles, however, in this case the Belgium National Annex of the Eurocode 7 has been used. The Belgium Annex for bearing piles supports all three models available in...
D-Foundations – Bearing piles(EC7-NL)
The standard module is intended for the design and verification of bearing piles. In short terms it allows for the input of projects, the analysis, and it provides tabulated and graphical output of results both on-screen and in a report....
D-Foundations – Feasibility
During the design of a piled foundation, the foundation is checked according to guidelines like the Eurocode. In practice, this the does not guarantee that the project is feasible. This may depend on many other local factors, among which the...
D-Foundations – Shallow Foundations (EC7-NL)
This module allows for the design of strip footings, as well as square or circular footings. The verification is based on the Eurocode 7 design code for shallow foundations, and the Dutch National Annex. The Shallow Foundations module takes into...
D-Foundations – Tension Piles(EC7-NL)
For some constructions a foundation capable of dealing with uplift forces is needed. A foundation on tension piles may offer a more economical alternative to constructions that counter the uplift forces by ballast. The tension pile module is used to...
Demo / images
D-Foundations is available in the following packages:
- Bearing piles(EC7-NL)
- Shallow Foundations
- Tension Piles(EC7-NL)
- Bearing piles(EC7-B)
The Educational package is the same as the Full package, but available at a reduced price.
We are here to help you with all your Deltares software products and solutions.
Over the last decades, Deltares has been developing and improving D-Foundations, which comes with everything a modelling professional needs in a flexible, stable, robust, easy-to-use modelling suite. Deltares offers high quality software services to consultancy firms, governmental organizations, universities and research institutes worldwide, using these software products.
The implementation of the Belgian method is at this moment still based on the guidelines published in 2008. If and/or when we will update the model to the latest version of these guidelines is not yet decided upon.
When using very low pile loads for the Verification option of the model Tension Piles the program is likely to crash when the report is being generated. This crash is caused by the fact that in those circumstances very small displacements (pile rise) are calculated which in turn crashes the determination of the pile/CPT combination where the displacement is the largest. A simple work around for this problem is to use more realistic values for the pile loads.
The reason for this error is that the program divides the given pile plan in subgroups to be able to properly calculate all piles with the proper pile group effects. This division is done based on the dimensions of each pile type. When these dimensions differ (too much), this can lead to different pile group divisions. And this is something the program can not handle as all results are grouped per pile type per pile group. The simple solution is to make sure you perform the calculation per pile type.
Instead of presenting the level for which the bearing capacity is reached for all CPT’s at the appropriate decisive case (ksi3 or ksi4), the level that is presented now is, in fact, the very first level encountered during calculation where the bearing capacity is met, regardless of CPT or appropriate decisive case.
According to article 184.108.40.206 (d) and Figure 6.b of the Eurocode NEN 9997-1+C2:2017, the influence depth z_e must be determined using the characteristic value of the effective friction angle.
If the determination of the influence depth is performed iteratively, then D-Foundations uses the design value instead of the characteristic value, which is not correct.
However, if the determination is not iterative (for example in case of only one layer), then the characteristic value is used, the influence depth is therefore correct.
Frequently asked questions
In the determination of the proper calculation case for the undrained as well as the drained situation, Case A (homogenous soil profile) will only be used as such in D-Foundations when the soil profile contains only one cohesive layer. When a profile consists of multiple layers, even if these layers use one identical cohesive material, Case A will not be selected.
The Release Notes can be found here
DFoundation determines which layers are alongside the pile and checks their type. For calculations based on fixed pile tip levels, this is no problem. However when a trajectory (or in fact a set of pile tip levels) is used, THE pile tip level required for the determination, is not clear. So for this, DFoundation uses the deepest pile tip level from the trajectory for the determination.
No, CUR 2001-8 is not (yet) part of D-Foundations. It is however on the wish list for a coming version.
For now, D-Foundations performs two calculations for this pile type. First, it is considered to be a closed steel pile calculating the bearing capacity based on a closed pile tip and taking the shaft friction only on the outside of the pile. Second, it is considered as an open pile calculating the pile tip capacity on the rim of the pile only and taking the shaft friction from both the inside as well as the outside of the pile. From these two calculated bearing capacities, the lowest value is taken into account. This delivers a fairly accurate result.
The first data value in the first column is probably greater than zero. To prevent the message from occurring you will have to edit the gef-file (using notepad). Lookup the following headerline in the gef file: #MEASUREMENTVAR= 13, 0.000000, m, pre-excavated depth. Change its value from zero into the value of the first reading.
At present, the input of additional pore pressure is not possible for the model Bearing Piles (EC7-NL). This is because the standard does not take these pressures into account. However, the additional pressures do in fact influence the negative skin friction as well as the reduction of the CPT-values in cases where an excavation is part of the project.
The effect of an excavation is described in NEN 6743 220.127.116.11 / EC7NL 18.104.22.168
Here it is stated that the CPT-values should be reduced based on the effective vertical stress before and after the excavation. This article does not provide a model for the determination stresses.
Negative skin friction is described in NEN 6743 6.2 / EC7NL 22.214.171.124
The determination of the negative skin friction too is dependent of the effective vertical stress. Here a specific model for the determination of the stresses is given and that model is based purely on a hydrostatic pore pressure.
D-Foundations uses the given specific model for both the cases where effective stress plays its part, this to be consistent. However, when additional pore pressures do occur, the hydrostatic model used can calculate bearing capacities that are either too low or too high. So be sure to choose your phreatic level wisely when dealing with additional pore presures.
When in the additional data of the profile the “top of positive friction” is exactly the same as “pile tip level”, the “Indication bearing capacity” will keep the positive shaft friction at zero. When the top of the positive skin differs from the pile tip level, a positive shaft friction is calculated.
For calcualtion of the total settlement under limit state 1B for a stiff construction, the average settlement is calculated. Would the choice have been a flexible construction, the settlement would be the sum of the individual contributions, for which the values are first summed, and only then rounded.
This is the permanent load that will be present next to the pile. In the ‘Bearing Piles’(EC7-NL) model, this is used to calculate the negative skin friction and the subsidence of the pile group (w2d). It is also used as a correction for the excavation reduction, although this reduction never makes a positive contribution; eg. a small excavation and large superimposed load does not result in an increase in the bearing capacity.
No, the maximum stress increase when calculating the subsidence is the maximum stress increase displayed as a percentage of the foundation pressure. This is not similar to the 20% limit in the norm, as this % applies to the stress increase itself. The maximum stress increase provides an indication of the reliability of the subsidence calculation. The subsidence calculation may be considered reliable if the percentage is at least 80%.
In Article 6.1 of NEN 6744, according to the norm, layers with a stress increase less than 20% do not contribute to the subsidence and do not have to be included in the subsidence calculation. Deltares considers this percentage too high, we only neglect layers having a stress increase below 5%. For this reason the subsidence table contains two columns; following the 20% as well as the 5% criterion. It is up to the user which value set to apply.
D-Foundations calculates the stress increase in the middle of the layer. A thick layer can have a stress increase in the middle that is less than the defined 20% or 5%, so that according to the norm no settlement needs to be determined. As settlement can occur in the top part of the layer one may overrule this assumption. It is advised to add thin layers at levels where the stress increase is less than 20% or 5%, in most cases one will add ‘dummy’ layers just below the foundation level.
Check the sampling rate versus depth of your CPT or SPT; very low sampling rates may cause inaccurate results.
This is the permanent load that will be present next to the pile. In the Tension Piles (EC7-NL) model, the weight of the surcharge is included in the unit weight.
When calculating for a pile group, the compaction by surrounding piles can be included (‘Options/Use Compaction’). This compaction is expressed in an augmentation factor of f1 that results in a linear increases of the cone resistance. In reality the value of f1 will usually not exceed 1 to 3. In arithmetical term, there is nothing against f1 > 10; the program simply continues to calculate. In such cases, however, you are advised to check the material parameters, as particularly unrealistic e_min and e_max values can be produced. If necessary, for sand use the values 0.4 and 08 in this case.
In accordance with EC7-NL, the top of the tension zone may not be higher than 1 m under the surface/excavation level. The program automatically makes this correction.
The GEF verification tool of the CUR does not contain all checks to verify if a GEF file meets the requirements of the GEF-CPT-Report definition. For example, according to the GEF-CPT-Report definition: Column 1, the sounding length, must always be in metres; the second column must contain the cone resistance values in Mpa. Though this is checked by D-Foundation , this is not checked by the CUR tool, therefore D-Foundation may reject files that are compliant to the CUR tool verification. To solve this problem one may edit a GEF file using the GEF>PlotTool.
- Operating systems:
- Windows 10 (version 20H2)
- Hardware specifications:
- 1 GHz Intel Pentium processor or equivalent
- 512 MB of RAM
- 400 MB free hard disk space
- SVGA video card, 1024 x 768 pixels, High colors (16 bits)
- For use of the Feasibility module an Internet connection is needed.
|Version 21.1 (2021-01-25)|
Download Release notes D-Foundations 21.1
|Version 126.96.36.199 (2019-10-11)|
Download Release notes D-Foundations
|Version 188.8.131.52 (2019-03-28)|
Download Release Notes D-Foundations 184.108.40.206
|Version 220.127.116.11 (2017-05-23)|
Download Release Notes D-Foundations 18.104.22.168