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Figure  11-26.-Side-by-side  dozing.
Figure 11-28.-Spreading.

Equipment Operator Basic - Beginning construction equipment operators manual
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Figure 11-28.-Spreading. Figure 11-29.–Culvert backfilling. SPREADING.—  Dozers  are  ideal  for  spreading  fill material brought in by haul units (fig, 11-28). Position the blade in a straight position, so the material is drifted directly under the cutting edge. BACKFILLING.—   Backfilling is the process of replacing excavated earth, as shown in figure 11-29. When a culvert is backfilled, the dozer should not cross the culvert unless there is at least 12 inches of compacted material on top of the culvert. If a bulldozer is used to bacfill  a  culvert,  the  best  method  is  to  make  diagonal passes over the material, ending each pass with a swing that brings the blade in line with the culvert. The  angle  blade  is  preferred  for  bacfilling  a trench, because material can be side cast into the trench while maintaining a steady forward motion, as shown in figure 11-30. Figure  11-30.Trench  backfilling. When a pipe trench is bacfilled, fine material is placed around the pipe and coarse material above it, so the  pipe  is  supported  by  well-compacted  material. However, covering the pipe to full depth in short lengths may concentrate weight and break pipe joints; therefore, cover  the  pipe  in  successive  layers,  rather  than  all  at once. NOTE:  Be  careful  in  pipe  trench  bacfilling  to avoid dropping large rocks directly on the pipe. FINISHING.—  Whether  clearing  or  spreading material on a roadbed, no job is completed until it has been smoothed and drainage is established. This is called finishing  and should be done at the end of each Shift. Blade the job lightly with about a half of a blade of dirt.  This  fills  in  any  low  spots  or  holes.  Leave  a windrow on the side that you are working toward. At the start  of  the  next  pass,  cover  half  the  blade  width. Continue  in  this  fashion  over  the  project  or  section  of the project you have worked that day before you shut down for the day. Finishing the project in this manner supports drainage and prevents having to walk over piles  of  dirt  or  through  mudholes. Ditching Rough ditching can be done with a dozer by making a series of overlapping passes at right angles to the line of the ditch. A “V” type of ditch can be dug with a dozer as follows: First, buildup a windrow along the edge of 11-15







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