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Figure 14-38.-Setting slope stakes
STRUCTURAL  SURVEYS

Engineering Aid 3 - Beginning Structural engineering guide book
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The steps taken by the instrumentman and the rodman  are  as  follows: 1. The instrumentman determines the center- line cut by subtracting 350.7 ft from 364.0 ft to get  the  cut,  or  13.3  ft. 2.  The  rodman  holds  at  the  center  line  for a check. The rod should-read 369.3 (the HI) minus 364.0,  or  5.3  ft. 3. The instrumentman calls to the rodman, “Cut  13.3  feet.” 4.  The  rodman  computes d=  20+(1  x  13.3)  =  33.3 as he walks to the left. 5. As he approaches about 30.0 ft from the center line, he estimates that the ground has a fall of  4  ft.  Therefore,  he  computes  the  new  cut  as 13.3  –  4.0,  or  9.3  ft. This  means  a  new  d  of 20  +  (1  x  9.3)  =  29.3  ft. 6. The rodman sets up the rod 29.3 ft from the  center  line,  as  measured  by  metallic  tape. 7. The instrumentman reads 10.1 on the rod and  computes  the  new  cut  as 369.3  –  (350.7  +  10.1),  or  8.5  ft. NOTE: Here you can also use the grade rod and ground rod values as explained earlier; the new cut then will be 18.6  –  10.1  =  8.5  ft. Refer  back  to  figure  14-36. 8.  The  instrumentman  calls,  “Cut  8.5,”  to the  rodman. 9.  The  rodman  computes d  =  20  +  (1  x  8.5)  =  28.5  ft. He knows, therefore, that 29.3 ft from the center line  is  too  far  out. 10. Figuring that the ground rises about 0.1 ft  between  29.3  left  and  28.5  left,  the  rodman calculates that the more nearly correct cut will be 8.5  +  0.1,  or  8.6  ft. 11. By using this cut, the rodman calculates the new d as 20  +  (1  x  8.6), and  sets  the  rod  at  28.6  ft  left. 12. The instrumentman reads and  computes  the  new  cut  as 369.3  –  (350.7  +  10.0) = 10.0 on the rod 8.6  ft. 13.  The  instrumentman  calls,  “Cut  8.6,”  to the  rodman. 14. The rodman sees that the actual cut of 8.6 ft agrees with his estimated cut of the same, and calls,  “Cut  8.6  at  28.6,”  to  the  instrumentman. 15.  The  instrumentman  checks d  =  20  +  (1  x  8.6)  =  28.6, signals  the  rodman,  “Good,”  and  makes  the following  entry  into  the  field  book: 16. The rodman marks a stake with 15 + 00 and C86 and  drives  it  in  the  ground  at  28.6  ft  left. More often, slope stakes may be set by using a  hand  level.  Their  distances  out  are  generally measured to the nearest half or tenth of a foot. If a slope stake is placed in an offset position, the offset distance is also marked on the stake so the equipment  operator  is  not  confused  about  its actual location. Slope stakes are seldom used in areas  requiring  less  than  2  ft  of  cut  or  fill. Curb and Gutter Stakeout For a thoroughfare that will have a curb and gutter,  these  items  are  usually  constructed  before the finish grading is done. The curb constructors obtain their line and grade from offset hubs like those described previously. Guided by these, the earthmovers  make  the  excavation  for  the  curb, the  formsetters  set  the  forms,  and  the  concrete crew  members  pour,  finish,  and  cure  the  curb. Once the curb has been constructed, shaping the  subgrade  to  correct  subgrade  elevation  and laying the pavement to correct finished grade is simply  a  matter  of  measuring  down  the  correct distance  from  a  cord  stretched  from  the  top  of one  curb  to  the  top  of  the  curb  opposite. 14-40







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