A German method of lining roadways subjected to heavy pressures. It consists of a closed circular arch of specially shaped precast concrete blocks. The blocks, which are wedge-shaped, are made in two sizes for each lining and erected in such a way that alternate blocks offer their wedge action in opposite directions--the larger blocks toward the center of the roadway and the smaller outward. This arrangement gives a doublewedge effect so that part of the lateral pressure exerted by the strata on the lining is diverted axially along the roadway.