SkyCiv Foundation provides a user-friendly interface paired with powerful design to easily model isolated foundations. The Isolated Foundation user-interface is composed into 4 tabs: Details, Foundations, Input and Results.
I. Details
Once the user has chosen a design code, the user will be presented with the “Details” tab as shown below. The units will be chosen automatically based on the design code chosen
Figure 1. Project tab details
The user can fill the information for the project details, such as
- A Project Name
- A Project ID
- Your Company Name
- The Designer
- The Client
- Project Notes (open ended notes)
This information will be inserted into the generated design report.
II. Foundations
Figure 2. Foundation tab details
Summary of inputs on the “Foundation” tab:
- Foundation ID – assign numerical identification to each foundation.
- Type – select “Isolated Foundation” from the drop-down menu.
- Supports – boundary conditions for the foundation (Refer to Figure 3)
Pin (FFFFRR) – resists vertical and horizontal forces, torsion, but bending moments about local Y and Z axis
3D Pin (FFFRRR) – resists vertical and horizontal forces ONLY
Fixed (FFFFFF) – resists vertical and horizontal forces, as well as moments - SW – self-weight factor
- Status – resultant of foundation design
Pass – the input parameters in the foundation is adequate.
Fail – the input parameters in the foundation is not adequate. - Edit – click this to start inputting data and edit your foundation
- Delete – delete the foundation
Figure 3. Type of Supports
III. Input
Figure 4. Selecting the Isolated Footing on the drop-down menu.
Users can establish the type of foundation as shown in Figure 4, select “Isolated Footing” to bring up this view
Figure 5. Foundation Tab
The “Input” tab can be separated into three separate tabs, each serving a specific purpose:
- Left Tab
Separates the different input categories such as: Footing, Column, Soil, Materials, Loads, Reinforcement and Design Parameters. - Screen Tab
User can select different diagram configuration such as Geometry, Analytical or both simultaneously (shown in Figure 6). This is where dimensions, units, and analysis graphics of the footing are shown. - Right Tab
Changes in accordance to which input configuration is selected. This is where all of the information with be inputted.
The Screen tab (model space) in the middle can be changed to three different view by clicking the required button in the upper right of the Screen tab. Figure 6 shows these three views.
Figure 6. (left) Geometry Diagram (center) Analytical Diagram (right) Both Geometry and Analytical Diagram
Lets go over the different input categories in a little more detail.
Footing Configuration
Figure 7. Right Tab of selected Footing Configuration at the left tab.
See Figure 8 for the nomenclature of the foundation dimensions:
Figure 8. Foundation with designation
Column Configuration
Figure 9. Right Tab of selected Column Configuration at the left tab.
Note: For λs Modifier – Per ACI 318-14 Section 22.6.5.3 – The value of λs is 40 for interior columns, 30 for edge columns and 20 for corner columns.
See Figure 10 for the nomenclature of the foundation dimensions:
Figure 10. Foundation with designation
Soil Configuration
Figure 11. Right Tab of selected Soil Configuration at the left tab.
Note: Soil values are usually found in the Geo-technical Report.
Materials
Figure 12. Right Tab of selected Material button at the left tab.
Loads
When “Loads” are selected, a pop-up window will appear:
Figure 13. Loads input window after clicking Loads
Reinforcement
To navigate between the reinforcement in the X and Z direction, and the column reinforcement, toggle between them using the buttons on the upper right of the Right Tab with Reinforcement selected.
Figure 15. Right Tab of selected Reinforcement button at the left tab.
Figure 14 details the direction nomenclature for the X and Z reinforcement
Figure 14. Details of Reinforcement.
Rebar Code Reference:
- ASTM615 – American Society for Testing and Materials 615 : Standard Specification for Deformedand Plain Carbon-Steel Bars for Concrete Reinforcement
- N – Australian Rebar Class N
- PNS49 – Philippines National Standard 49 : Steelbars for concrete reinforcement – Specification.
Design Parameters
To navigate between different Design Parameters, toggle between them using the buttons on the upper right of the Right Tab with Design Parameters selected. This section will change depending on the
Figure 16. Right Tab of selected Design Parameters button at the left tab.
IV. Results
After hitting the Check Design button, your design will be directed to the “Results Page”. Each column, except for the last two, represents a design check completed by the Foundation module. The values are represented as unity ratios, where anything under 1.0 is a PASS, and anything over 1.0 is a FAIL. The last two columns represent the area of steel in both directions of the footing.
Figure 17. Results Output page
Summary of column representations:
- DIM
Ratio of user’s input dimensions over required design dimensions. - Overturning
Ratio of overturning moment experienced over allowable overturning moment. - Sliding
Ratio of sliding force experienced over sliding resistance. - Soil Pressure
Ratio of soil pressure from experienced loads over allowable soil pressure. - One-Way
Ratio of ONE-way shear demand over capacity. - Two-Way
Ratio of TWO-way shear demand over capacity. - Flexure
Ratio of flexural demand over flexural capacity. - Asx
Reinforcement area along x-axis. - Asz
Reinforcement area along z-axis. - Status
Indicates that the foundation design is PASS or FAIL - Report
Click to see detailed calculation of the design foundation
Reference:
- Building Code Requirements for Structural Concrete (ACI 318-14) Commentary on Building Code Requirements for Structural Concrete (ACI 318R-14). American Concrete Institute, 2014.
- Taylor, Andrew, et al. The Reinforced Concrete Design Handbook: a Companion to ACI-318-14. American Concrete Institute, 2015.
