| 摘要 |
An elongated plate beam (10) has a plurality of longitudinally extending downwardly directed ribs positioned in parallel spaced relation to form a pair of lateral ribs (18, 20) and a center reinforcing rib (22). The plate beam (10) is of a length to span the width of a mine passage and includes a top surface (26) for abutting the mine roof. Openings (30) are spaced along the length of the plate beam (10) and extend through the center reinforcing rib (22). A roof plate is positioned in abutting relation with the plate beam bottom surface (28) in overlying relation with each opening (30). Roof bolts extend through the roof plates and openings (30) into engagement with the walls of bore holes drilled in the mine roof. An enlarged end of each roof bolt bears against the respective roof plate to apply an upward force upon the plate beam (10) to position the plate beam in roof supporting relation with the mine roof over the entire width of the mine passage spanned by the plate beam. In a modification the roof plates each include a center rib positioned in complementary interengagement with the plate beam centre reinforcing rib to increase the surface to surface contact of the roof plates with the plate beam (10) to increase the bearing force applied by the plate beam to the mine roof. <IMAGE> |
