The Engineering feature allows you to perform structural calculations of your scaffold right inside the app with just a few extra clicks. Design, plan, and calculate all in one place.

Table of contents

• Intended use
• Recommended approach
• Important limitations
• Further details
• Step-by-step guide
• 1. Enter Engineering mode
• 2. Calculation settings
• 3. Calculate
• 4. View results
• 5. Create a new calculation
• Stabilizing a scaffold
• Error / warning messages
• Failed calculation
• Warnings alongside results
• Load increase due to sway
• Lift of base plate
• Slip risk
• High bending moment in standards
• Terminology Translations

Intended use

The Engineering tool is intended to be used together with the manufacturer’s technical documentation. With the Engineering feature in Scaffcalc, you can evaluate the stability of your scaffold and visualize forces in components, ground supports, and anchor supports. Use these results alongside the manufacturer’s documentation to assess your scaffold design.

This is the first version of the Engineering tool. It has limitations that will be addressed in future versions. The intended use of the final version is to rely fully on the Engineering tool alone.

Recommended approach

The following describes the recommended methodology for interpreting the results. To learn how to use the feature to calculate results, follow this step-by-step guide.

For each new scaffold calculation, start by checking the displacements. Displacements show how much the scaffold moves under the applied loads. If the scaffold moves significantly in any direction, consider improving the stability of the scaffold. As a rule of thumb, use H/120. That is, for any two points on a standard with a height difference H, the relative horizontal displacement between those points should be no more than H/120. Note: To assess compression in the standards using the manufacturer’s tables, the standards need to be stabilized horizontally at a known interval (via anchors/ v-anchors/ diagonals).

Next, check for any lift of base plate warning. If shown, the base plate wants to lift and must be anchored to the ground or resisted with counterweight. Click here to read about how to handle lift of base plates.

Next, check for any slip risk warning. This will show up as a warning if found, as will tension in the base plates. Click here to read more about slip and how to handle it.

Upcoming: A warning for high bending moment in standards will be added in a future update, to help identify standards with critical moment demand.

Once the scaffold is well designed based on the displacements and warnings, you can check the forces on the elements and supports against the manufacturer’s documentation to verify that they are within the allowed limits. Note: The forces shown in Scaffcalc are dimensioning forces, which means they include safety factors. They should be compared with the manufacturer’s design capacities. If the manufacturer only states permissible loads or forces, multiply those values by 1.5 to compare with the forces shown in Scaffcalc. The unit of forces in Scaffcalc is kN. 1 kN equals approximate 100 kg.

Important limitations

The current version of the Engineering Tool has limitations that will be handled in future updates to the feature. Some limitations will affect the resulted behavior of the scaffold.

The most important limitations are:

• No structural verifications

Structural verification, including a calculation report, will be addressed in future versions of the Engineering feature. With the current feature, results must be verified against manufacturers tables.

• Layher Allround scaffolds only

The feature currently only suppors Layher Scaffolds. More specifically, Layher Allround LW.

• Anchored ground supports

All ground supports are modelled as fully anchored to the ground, meaning instead of lifting when exposed to heavy wind, the will not move but instead display a tension force in the ground support. You can mitigate this by either take care of the forces (by use of counterweights / ground anchors) or by changing the scaffold design (widening of the base for example). Modeling of counterweights will also be possible in future versions.

• Default friction coefficient

The friction coefficient for the base plates on the ground is set to a default of 0.5. This means the results assume the base plates start slipping if the horizontal force exceeds 50% of the simultaneous vertical compression force in the base plate.

• Connections: constant stiffness and no eccentricity

This first Engineering version models connection stiffness as constant, independent of the applied force. Also, there is currently no eccentricity applied to the connections.

• No reduction in regard to facade openness

In the first version of Engineering, the permitted wind load reduction is not considered when an unclad scaffold is mounted close to a facade with few or no openings. Future versions will let the user select facades and specify openness to be considered in the calculation.

• Load on bird cage scaffolds

The vertical platform load is uniformly distributed in each bay on all scaffolds. The EN 12811 note that the load on bird cage scaffolds should be applied over a maximum surface area of 6 square meters (with a reduced imposed load on surrounding areas) is not considered.

Further details

If you are interested in the details of the Engineering 1.0 Tool, please read the technical documentation:

Step-by-step guide

Follow the steps below to calculate the forces on your scaffold and view the results.

1. Enter Engineering mode

Once you’ve built a scaffold you wish to calculate the forces on, exit Build mode and enter Engineering mode using the switch at the top right:

In Build mode, you can build and edit your scaffold.

In Engineering mode, you can calculate and view the forces on the scaffold.

You can easily switch between Build and Engineering mode at any time; all edits are saved.

2. Calculation settings

Next, enter the calculation settings specific to your scaffold project. These determine the loads applied to the scaffold. To learn more about each setting, click the arrow beside it below.

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Reference wind speed

One option is to choose indoor: no wind.

For outdoor:

Basic wind velocity (m/s) per national standards. Click the arrow next to the country whose wind map you want to see:

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Germany

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Sweden

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Terrain type

Choose the terrain type that best matches the project site from the list below. If you’re unsure, choose the lower option.

3. Calculate

Once you’re happy with your settings, press Run Calculation. The app applies the loads based on your inputs and evaluates all relevant load scenarios. Press Abort calculation if you wish to cancel the calculation before it is finished.

4. View results

Once the calculation is finished, the results will be saved in the list under Calculation Results. Each result corresponds to an individual (unconnected) scaffold. Select a scaffold in the drop-down list to view its results.

The first result in the list is selected by default, and that scaffold’s displacement is displayed. You can return to this list at any time to switch between results.

After selecting the result you want to view, toggle the different results below.

If any error/ warning messages appear for the calculation, read about it here.

Selected Result Settings

Click on the arrow to display which calculation settings the currently selected result is calculated with. Double check that your calculation settings are correct, if not, create a new calculation.

Displacements

The displacements are automatically visible when selecting a result to view. The displacement visualises the movements of the scaffold for the single worst case load scenario. You can hide the scaffold, in the list to the very left, if you wish to display the displacement shape only. To see the displacement values, zoom in on the displacement shape.

Force results: Compression/Tension

Forces on the scaffold are grouped into compression and tension. When Compression is selected, only the greatest compression force occurring per component / support is displayed. When Tension is selected, only the greatest tension force per component/ support is displayed.

Note that since the maximum value per element is shown, the visible forces may not occur simultaneously.

Also note that for components/ supports with no tension force, nothing will be displayed while Tension is selected. For components/ supports with no compression force, nothing will be displayed while Compression is selected.

• Component Forces

Shows, for each element, the greatest force it is subjected to. If you have selected Compression, it shows the greatest compression in each element. If you have selected Tension, it shows the greatest tension in each element.

Set the maximum allowed force value to display forces exceeding this limit in red. Values are set separately for compression and tension forces.

Adjust the scale factor to change the size of the force visualisation.

Use the selection filter to filter out component types for easier visualisation.

• Ground Forces

Displays pressure/tension force from each standard on the ground.

Set the maximum allowed force value to display forces exceeding this limit in red. Values are set separately for compression and tension forces.

Adjust the scale factor to change the size of the arrows.

• Anchor Forces

Displays pressure/tension force from each anchor on the facade.

Set the maximum allowed force value to display forces exceeding this limit in red. Values are set separately for compression and tension forces.

Adjust the scale factor to change the size of the arrows.

• Beam Spigot Forces

Displays the force acting from a beam spigot onto a ledger / lattice beam.

Set the maximum allowed force value to display forces exceeding this limit in red. Values are set separately for compression and tension forces.

Adjust the scale factor to change the size of the arrows.

5. Create a new calculation

It is easy to go back and edit the scaffold or calculation settings to try a different alternative. In the list of results, click + create new calculation. This returns you to the calculation settings, which you can edit and then click Run Calculation again.

If you also wish to edit the model, then after clicking + create new calculation click on Build above to exit Engineering mode and go back to Build mode. Now you can edit the scaffold and retrace the steps to calculate the new forces.

Note: By editing the scaffold, all calculation results will be deleted. A warning modal will appear to prevent you from accidentally deleting calculation results.

Stabilizing a scaffold

This section is under construction.

Error / warning messages

Failed calculation

If a calculation fails, an error message will be displayed with the reason for the failure. Some alternatives of this error message are:

• Supplier not supported Only Layher Allround is currently available for calculations
• Attached with a ‘VIEW’ button If the error message includes a view button, the calculation found an error in the model that would cause the calculation to fail. Click the button to zoom to the error(s).
• Unstable scaffold If this is displayed, the scaffold is too vulnerable to lateral movement. A displacement shape will be visible to help you understand which direction is most unstable. Improve stability by stabilizing the scaffold.
• Unknown

If the error message simply states that the cause is unknown, try again. If the issue persists, please contact support.

Warnings alongside results

There are some warnings that can appear alongside the finished result to make you aware of some critical points in the scaffold.

Load increase due to sway

If the scaffold is vulnerable to horizontal movement due to the vertical loads applied in any load combination, the horizontal load in that load combination will be increased by a percentage (noted in the warning) to account for the sway effect. To avoid this load increase, try stabilizing the scaffold.

Lift of base plate

Lift of base plate means the base plate wants to lift off the ground. In Ground Forces (Tension mode), you can see the tension force required to keep the base plate in contact with the ground. If this is not addressed, it can lead to scaffold overturning. Reduce the lift by stabilizing the scaffold, or resist it by anchoring the base plate to the ground or adding counterweights. Click View in the warning to display the required counterweight for each node.

Slip risk

Slip risk in any base plate means that, in some load scenario, the horizontal force in the base plate is greater than 50% of the simultaneous vertical force. This could cause the base plate to slip or slide horizontally.

To solve this, first add any missing ledgers at the base of the scaffold. Next, try to stabilize the scaffold further and check for missing V-anchors.

If this cannot be solved by improving stability, anchoring the components to the ground or adding counterweights to the scaffold is the best solution. To calculate the necessary counterweight, the maximum ratio Horizontal Force (H) / Vertical Force (V) is displayed per base plate. The necessary added weight can be calculated as 2 x H - V (without any negative signs). Example: H = 4 kN, V = -4 kN. Counterweight = 2*4 - 4 = 4 kN.

High bending moment in standards

This is an upcoming feature. Moment forces are currently not visible / warned about to the user.

Terminology Translations