Designing a pier cap from DXF

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By following this step-by-step tutorial, you will learn how to design and code-check a pier cap by DXF references in IDEA StatiCa Detail.

1 New project

Let’s launch the IDEA StatiCa and select the application Detail. Create a new project by clicking New. Wizard window is opened and you can start with a selection of proper concrete grade and cover. Then continue with Members 1D or wall in the General input section.

Pier cap from DXF - New project
Pier cap from DXF - grade

This will load a blank project where we start from scratch.

2 Geometry

Start with the addition of a wall element by the Import DXF button.

Pier cap from DXF - Import

A dialog to locate and open the desired DXF file will pop-up. After the selection of pier_cap.dxf (available in source files), you will land in a dialog for selection. Select the part of the outline of the pier cap (if you used lines in DXF continue with Consecutive button) and click on Outline. Finish the selection by OK button.

Pier cap from DXF - Geometry

Then import the upper part of the pier cap from the same DXF file.

Pier cap from DXF - Import

The shapes of the wall elements have been generated by DXF, but the 2D DXF reference lacks the information about thickness, thus you need to adjust it manually now. Set the Thickness for both W1 and W2 members to 1,20 m.

Pier cap from DXF - Thickness

As the warning message on the left tells us, our structure is statically overdetermined, so you need to add boundary conditions. To create line support, click on the plus button and select the third type in Supports section.

Pier cap from DXF - Supports

Constraint the support in X, Z and Ry directions and change the edge number to 7. Also, switch off the Compression only functionality. The edge numbers can be seen in the Main window.

Pier cap from DXF - Supports

As a Point force-placed directly on the edge of a pier cap would crash the concrete locally in compression, we will use bearing plates to distribute the load more evenly. To add one, press Plus button once again and in Load transfer devices section pick the first - Bearing plate.

Pier cap from DXF - Load transfer

Change the Width to 0,40 m and the Thickness to 0,040 m, then the Edge number to 3 and shift its X-Position to 0,45 m.

Pier cap from DXF - Position

Then copy the Bearing plate and change its position to be measured From end.

Pier cap from DXF - Geometry

3 Loads

One load case LC1 was automatically added by the software. You need two load cases to distinguish between permanent and variable loads and three combinations to cover one ULS and two SLS combinations (Characteristic and Quasi-permanent) for all checks.

Pier cap from DXF - Loads

Let's modify the automatically added load case LC1 for permanent effects. In Load impulses tab click on the Plus button and apply a point load. It will be automatically placed on one of the bearing plates.

Pier cap from DXF - Loads

As the last step, change its value to -2500 kN.

Pier cap from DXF - Loads

Copy that force to the other bearing plate BP2.

Pier cap from DXF - Loads

Switch back to Load cases & Combinations tab to create LC2 load case by plus Load case button. Change the load case type to the variable.

Pier cap from DXF - Load case

Repeat the steps for the addition of point load.

Pier cap from DXF - Load case

Adjust the value of force.

Pier cap from DXF - Loads

Copy the force to the bearing plate BP1.

Pier cap from DXF - Loads

Let's go back to Load cases & Combinations for the last time. Create the first nonlinear combination by plus Combination button. The combination CO1 is set by default to ULS type. Set the partial factors after the definition of all combinations at once.

Pier cap from DXF - Combinations

Now you can repeat the steps to introduce the second combination of CO2. This time, it will be SLS type and Characteristic.

Pier cap from DXF - Combinations

The last defined combination will be as expected - Quasi-permanent. Select one in the combo box right next to the SLS type selection.

Pier cap from DXF - Combinations

Now, change the partial factors for all combinations. To do that, click on the pen icon in any combination you defined and change the partial factors as you see in the following picture.

Pier cap from DXF - Combinations

The last step in the definition of loads will be the unticking of checkboxes for load cases. The calculations will be performed just for the ticked items and by excluding load cases, you will speed up the calculation. You will require the checks for three combinations.

Pier cap from DXF - Combinations

4 Reinforcement

The next step is to reinforce the model. Combine the definition from scratch in IDEA with the definition by the DXF file. In this tutorial, we assume that the user knows how to reinforce a pier cap and prepared some reinforcement in DXF in advance from drawings, thus we leave the tools for reinforcement design for another tutorial and you can switch to Input/Edit.

Pier cap from DXF - Reinforcement

In input mode, start with the definition of the first item by DXF reference. Click on Import DXF.

Pier cap from DXF - Reinforcement

A dialog to locate and open the desired DXF file will pop-up. After the selection of pier_cap.dxf (available in the source files), you will land in a dialog for selection. Continuously select the polylines (rebars shape) in order showed on the following picture and click on Select after each polyline (the order is not important in general, we just want to keep track in this tutorial, when we will talk about the specific name of an item). Finish the selection by OK button.

Pier cap from DXF - Reinforcement

The 2D DXF file transfers the global width of a polyline as the diameter for each rebar, but it does not contain information about the number of bars in the perpendicular direction and we need to adjust them manually.

Change the number of bars in a layer for the group of bars GB1 to 10.

Pier cap from DXF - Reinforcement

Repeat the previous step for the groups GB2, GB3, and GB4 and set the number of bars in a layer to 8.

Pier cap from DXF - Reinforcement

To finish the reinforcement in this example, combine the reference from DXF with reinforcement defined in IDEA StatiCa Detail. In this case, add some horizontal and longitudinal reinforcement into the pier cap and a few layers of reinforcement representing the stirrups in the pier. Click on the plus button and select the first reinforcement item Group of bars.

Pier cap from DXF - Reinforcement

Change the definition to On outline or opening edge. Then adjust the number of layers, their distances, the diameter, number of bars in a layer, anchorage type for both ends and edge according to the following picture:

Pier cap from DXF - Reinforcement

Use the copy function to create GB6 which will represent the stirrups and switch the edge to 7. Set all parameters according to the picture bellow:

Pier cap from DXF - Reinforcement

The last reinforcement items will introduce the longitudinal reinforcement of the pier cap. To do that, add a new group of bars. Change the properties as follows:

Pier cap from DXF - Reinforcement

Use the copy button for the last time. Change the edge to 8.

Pier cap from DXF - Reinforcement

Switch in the navigator to Check, this is how your final reinforcement should look like:

Pier cap from DXF - Reinforcement

5 Calculation and Check

Start the analysis by clicking Check in the ribbon. The analysis model is automatically generated, the calculations are performed and you can see the summary of checks displayed together with the values of check results.

To go through the detailed checks of each component, start with the Strength tab. This will show concrete checks such as utilization in stress, principal stresses, strains and also a map of reduction factor kc which can be switched on the ribbon.

For detailed results of reinforcement, you need to click on the row Reinforcement. This will change the ribbon icons and also will unroll the table for results. You can display the results for strains and stresses in each bar and their utilization.

All results can be displayed in the same way. Let´s show the difference in the ribbon for SLS checks of crack-width and deflection. Besides the icons to switch between the results, there are settings in the ribbon to set the limit value of cracks or to display the results of deflections from short/long-term models.

6 Report

At last, go to the Report Preview/Print. IDEA StatiCa offers a fully customizable report to print out or save in an editable format.

Pier cap from DXF - Report
Pier cap from DXF - Report

You have designed, optimized and code-checked a pier cap according to Eurocode.

Sample files

Pier cap from DXF

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