>>1287197well you probably need to calculate that. earth forces are very big. and dynamic loads can be high too like snow or rain water soaked earth.
in the picture the shed leads the load roof to ground. with earth works its outside in. that's the reason a lot of underground stuff is round. there is even force trying to push up as any hollow object will float up in wet earth.
but if you add a steel cage and enough concrete it would solid for most disasters. but then you might be in the price range of dedicated solutions. plenty of those around
https://www.youtube.com/watch?v=I8-ARZE6wTo 