The ornamental design for a shoringsystemjoist, as shown and described.
FIG. 1 is a front plan view of a shoring system joist for use in concrete framework showing an embodiment of my new design, the back plan view being a mirror image thereof.
FIG. 2 is a top plan view thereof.
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is a right side plan view thereof, the left side being a mirror image thereof.
Shading lines are used to show solid structures and are not intended to indicate surface decoration.