Product Catalog

4-flange steel liner plates, a system successfully used since 1926, provide lightweight, easyto-handle, and safe support for soft ground. Jennmar tunneling and shaft construction are made in the USA (Sinton, TX and Louisville, KY).

4-flange liner plates manufactured by Jennmar Civil are available in 16" and 24" widths as corrugated or smooth plates. Liner plates are formed from one piece of steel to provide longitudinal and circumferential flanges with optimum load-bearing and bending resistance characteristics.

4-flange liner plates can be galvanized, bituminous-coated, and polymer-coated (Obduro®). Grout holes and plugs can also be coated. Gasketed and tapered liner plates can also be manufactured for particular conditions. Liner plates can be installed as stand-alone structures or in conjunction with steel ribs if additional support is required. Diameters of tunnels and shafts supported solely with 4-flange liner plates can vary from 4’ to 20’ (1.2 to 6.1 m).

The Liner Plate assembly distributes and transmits the load to the surrounding ground in tunnels. As a steel liner plate ring takes load vertically, it tends to deflect inward at the top and outward at the sides. Thereby, the ground resists deflection of the lining by developing a passive force equal in magnitude and opposite in direction to the force exerted by that of the lining.