Grain store base plates

[Neddy flanders]

on a 18mx12m building with 4m up rights and 2x1m concrete panels in 4.5m bays, how far underground are holding down bolts?
If they're at the surface or say 300mm below is that enough. Does the wall strength come from the rafters holding the top of each column together.
203x133x25UB Columns, which may seem light but with 2 extra posts in each bay behind panel.

 

[Forever Fendt]

4m sounds very low to me is it a portal or a mono pitch roof, in my opinion the 2 extra posts will do very little, take it this is a refurb or alteration not a new build but in answer to your question 300mm below ground will be ok if you tie the bottom of the stansion into the floor slab i will see if I can find a picture for you

 

[Forever Fendt]

on a 18mx12m building with 4m up rights and 2x1m concrete panels in 4.5m bays, how far underground are holding down bolts?
If they're at the surface or say 300mm below is that enough. Does the wall strength come from the rafters holding the top of each column together.
203x133x25UB Columns, which may seem light but with 2 extra posts in each bay behind panel.

i only have a picture of the bracket a panel sits on and it is a corner post a 90deg rebar threads through the hole and goes 6ft in to the floor slab at 45deg if thats any help
,

 

[Frank_farmer]

I'd be more worried about the column size than how for in the ground it is. 203? Grainstore?

 

[Forever Fendt]

I'd be more worried about the column size than how for in the ground it is. 203? Grainstore?

yes it should be 305x165x40 and rafters 254x146x31this is same size but 4.8m high