Google ‘Sheffield Bicycle Stands images’. Something shaped like that set into concrete would give you something to both lock to and lean the bike upright against.
If you have a wall to lean the bike against Kryptonite and others make anchors with a hardened steel shackle for a chain to go through. The shackle on the Kryptonite can lay flat into the anchor when not in use.
NOW….if you really loved your bikes you’d give them a spot inside your warm and cozy house
‘The negative feelings we all have can be addictive…just as the positive…it’s up to
us to decide which ones we want to choose and feed”… Pema Chodron