(10) US2021222446 (A1)
(57) An object of the present invention is to provide a method for accurately modifying a concrete slab on subsided ground by injecting an expandable resin below the concrete slab more than once, which also allows for easy control of the work process. The method of the present invention as a means for resolution includes performing the following steps: on a concrete slab in an area including a region where ground subsidence has occurred, determining points to drill injection holes for injecting an expandable resin at a pitch of 0.5 to 2.0 m in a grid pattern or a staggered pattern; injecting an expandable resin below a point where the subsidence of the concrete slab is severest and expanding the expandable resin to push up the concrete slab at most 30 mm more than once.
(71) UPCON CORP [JP] + (UPCON Corporation)
(73) MATSUDO NOBUKAZU [JP]; KAWAGUCHI KOJI [JP] + (MATSUDO, Nobukazu, ; KAWAGUCHI, Koji)