PipeLocks have been around for a quarter of a century. They have become the standard solution for foundation of posts in a number of fields. A lot of flavours were developped. Specials with or without precast concrete, adaptations for shallow installation, autonomous constructions for planted installation,
The latest ‘fashion’ is a PipeLock with precast concrete for the smaller sizes. This way the authorities are ensured at least some sturdy mass is aroud the system to withstand a collision.
Another runner is the autonomous ‘Essential’. Sizes over ø89mm can get a steel ground-tube in order to plant the PipeLock like it is a post. At least the calculations add up for an EN40 installation, the system can be needled past underground cables and pipes, the installed post is mobile (can be easily removed), and can become impact resiliant with tight paving or addidional concrete pour.
Anyway, check the size categories for all the available types.