The 10' x 6' optical table is seating on 6 tripods. Each tripod leg has 3 feet. They are supported by jack screws against copper plates on the concrete floor. These set screws allowed us to set the height, level and distribute the load of the table.
To lock this position of the table grouting is used around the jack screws and between the concrete floor and the tripod feet.
Once the grout set the load will be carried by the hole feet of 4" x 3.25" x3 = 39 sq inches per tripod leg
These ~4" thick grouted islands of 8-9" OD will be covered by 4" concrete. The area between the legs will be filled with 8" thick concrete.
Cement based grout, early height change 0 - 4%, hardened height change 0 - 0.3%
Atm2-3, pouring grout
Atm4, south west leg is done
Tomorrow: setting up ribbed bars, building frame to hold concrete and pour concrete