Retaining wall construction: Contractor superintendent holds rod at top of placed precast concrete panel and City surveyor/inspector checks elevation. Allowable tolerance = 1/8 inch. Two workers install blocking at mid-left of photo, to position panel against front flange of soldier beam H-section. The angle of the clips attached to the panel shows the crane is no longer supporting the panel. Instead, the bottom of the panel rests on steel shim packs, which can be adjusted in thickness to meet elevation requirements. Black polyethylene silt/mud fence/barrier at right protects land surface to its right from water borne construction silt/mud. Huron Parkway South of Huron River, Ann Arbor, MI, 2005.

Retaining wall construction: Contractor superintendent holds rod at top of placed precast concrete panel and City surveyor/inspector checks elevation. Allowable tolerance = 1/8 inch. Two workers install blocking at mid-left of photo, to position panel against front flange of soldier beam H-section. The angle of the clips attached to the panel shows the crane is no longer supporting the panel. Instead, the bottom of the panel rests on steel shim packs, which can be adjusted in thickness to meet elevation requirements. Black polyethylene silt/mud fence/barrier at right protects land surface to its right from water borne construction silt/mud. Huron Parkway South of Huron River, Ann Arbor, MI, 2005.