> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/sel-faq/using-the-software/calculation-modules/beams2/beams/spike-in-shear-demand-when-poi.md).

# Spike in Shear Demand when Point Loads are Applied at Supports

Why point loads applied at supports caused an artificial shear spike, now resolved.

*10/03/2025: This issue has been resolved in all beam modules and is no longer relevant. Topic has been archived for posterity.*

There is currently a known issue in SEL when point loads are applied directly at support locations. This issue appears to be due to a precision/roundoff error which causes the point load to shift slightly off the support and leading to an artificial spike in the shear diagram. As a result, the reported member shear demands at locations immediately near the support are overly conservative.

![](https://1076748670-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FtBL2fEQRwrlKSM2irFL0%2Fuploads%2Fgit-blob-b20fc9035b62d37acfbfd1b418c8bb1d05426704%2FSpike%20in%20Shear%20Demand%20-%20Point%20Loads%20at%20Supports.jpg?alt=media)

This issue exclusively affects the beam design modules and occurs only when the point load is located **at the end of the span** (i.e., when the load location value equals the span length). Point loads with a location value equal to 0 are not impacted. It is important to note that calculated moments, deflections, and support reactions are not adversely affected by this issue.

We are actively investigating various solutions to minimize the occurrence of this problem while maintaining accuracy and precision in the results. In the meantime, the following steps can serve as a potential temporary workaround:

If the point load occurs at any support **except the final support**:

1. Delete the existing point loads where the location value equals the span length.
2. Re-add the point loads to the next span with the location value set to 0.

If your point load is at the final support:

1. If your beam configuration and loading allow, mirror the beam left-to-right so the point load is at the first support, with a location value of 0.
2. If mirroring your beam configuration is not possible:
3. Create a clone of the calculation with the artificial shear spike.
4. In the original calculation, delete any point loads that are directly applied at support locations.
5. You can now use this calculation (without point loads at supports) to check for member shear, bending, and deflection.
6. The clone created in Step (which includes point loads at supports) can be used for calculating extreme support reactions.


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