A brief case study by Tibor Horvath with Fakopp Pulling Test
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_01.jpg)
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_02-1024x656.jpg)
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_03-1024x655.jpg)
Conditions
- The measured tree stood in a suburban garden and has been marked for removal.
- The removal has been turned into a series of 6 pulling tests. First we measured the tree in its original state, then before every additional pulling test some of roots have been cut.
- For the calculation of the safety factors, the wind speed of 33 m/s (cc. 120 km/h) has been used.
- The purpose of the experiment was to reveal the effect of cut roots on the safety factor.
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_04.jpg)
Safety factor measurements
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_01.jpg)
Intact: 1.19
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_02-1024x656.jpg)
Excavated: 0.86
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_03-1024x655.jpg)
1 root cut: 0.61
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_08.jpg)
4 roots: 0.33
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_09.jpg)
7 roots: 0.27
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_10.jpg)
All 11 roots: 0.14
Results
![](https://wordpress.fakopp.com/wp-content/uploads/2023/01/cutroots_11.png)