Opinion's on best way to install testing fixture

Hello,
I work at a relatively small car company and am designing a fixture that will be hit by cars repeatedly. The fixture is 24 feet long, and will be taking significant forces to it's side. I intend to hold the fixture down with 9-12 bolts going along the backside, but I have some issues: 1) it must be removable and can't have threaded bolts sticking out of the ground, therefore I would have to use some sort of concrete anchor threaded insert. 2) I only have 6in of concrete depth to work with- I am planning on using 1in diameter bolts to handle the shear stresses, but with this diameter bolt I would need ~9 inches of concrete depth to use any sort of epoxy/ chemical style inserts. I'm at a standstill here, and would really appreciate some ideas- this is my first time working with concrete/ concrete anchors, so i'm not sure the best route to take.