Page 177 - Moving the Earth_ The Workbook of Excavation

BASEMENTS

BASEMENTS 4.17

FIGURE 4.16 Cutting jogs with a backhoe.
the west, the cut is brought a little beyond the jog, and the position then shifted to dig along the
outer line.
The machine may dig the south side by entering from the west and starting at the southeast cor-
ner. Excavation is carried back to the west line, first ditching the edge then digging out the cen-
ter. Care is taken to begin the spoil pile well west of the south room. The backhoe is then moved
off to the south and up to the room. It is first lined up to the west side of this room and makes a
cut from the main excavation to the south line of the room. It is then moved so as to cut the east
wall of the room, then digs out the rest of the room.
Another way to do this would be in the same manner as the north wall, treating the room as a
double jog. However, this would involve extra digging because the bucket needs considerable
width in which to cut down.
If the excavation site is a hillside, the work should be managed so that backhoe tracks will head
up- or downhill, not across. If the grade is steep, the backhoe should dig from downhill to avoid
the danger of being pulled into the hole if the bucket hooks into something solid.
If work must be done from the upper side, the stability of the ground should be checked, and
both tracks must be securely blocked against sliding.

OTHER SHOVEL RIGS

Dipper or Front Shovel. Front shovels (refer to Fig. 13.1) are seldom used in residential base-
ment excavations, but they can do a good job. For satisfactory results, the ground should be firm
at bottom grade, and the spoil should build into steep-sided piles.