0
1.9kviews
The staff reading taken along a levelling operation are given below the instrument shifted after taking 5th, 10th , 14th and 19th reading.

Arranged data in a tabular form and find the R.L of all the point by rise and fall method if 10th reading taken to BM of RL 185.635.

1.355, 1.605, 2.125, 0.685, 1.365, 2.015, 1.355, 1.385, 0.685, 2.105, 1.685, 1.155, 1.105, 2.105, 1.085, 1.345, 1.355, -2.015, 1.305, 1.655, 1.685 and 1.455.

0
44views
Station B.S I.S F.S Rise Fall R.L remark
1 1.355 185.205 1st RL
2 1.605 0.25 184.955
3 2.125 0.52 184.435
4 0.685 1.44 185.875
5 2.015 1.365 0.68 185.195 CP1
6 1.355 0.66 185.855
7 -1.385 2.74 188.595 Inverted staff reading
8 0.685 2.07 186.525
9 1.685 2.105 1.42 185.105 CP2
10 1.155 0.53 185.635 BM 185.635
11 1.105 0.05 185.685
12 1.085 2.015 0.91 184.775 CP3
13 1.345 0.26 184.515
14 1.355 0.01 184.505
15 -2.015 3.37 187.875 Inverted staff reading
16 1.655 1.305 3.32 184.555 CP4
17 1.685 0.03 184.525
18 1.455 0.23 184.755 Last RL
∑B.S = 7.795 ∑F.S = 8.245 ∑RISE = 9.02 ∑FALL = 9.47

Step1. Calculate rise and fall:

1. BS of point 1- IS of point 2 = 1.355- 1.605 = - 0.25 (-ve means fall)

2. IS of point 2 – IS of point 3 = 1.605 – 2.125 = -0.52 (- ve means fall)

3. IS of point 3 – IS of point 4 = 2.125 – 0.685 = + 1.44 (+ve means rise)

4. IS of point 4 – FS of point 5 = 0.685 – 1.365 = -0.68

5. BS of point 5 – IS of point 6 = 2.015- 1.355 = +0.66

6. IS of point 6 – IS of point 7 = 1.355-(-1.385)= +2.74

7. IS of point 7 – IS of point 8 = -1.385- 0.685= - 2.07

8. IS of point 8 – FS of point 9= 0.685- 2.105= - 1.42

9. BS of point 9 – IS of point 10 = 1.685 – 1.155=+0.53

10. IS of point 10 – IS of point 11= 1.155-1.105=+0.05

11. IS of point 11 – FS of point 12=1.105-2.015= -0.91

12. BS of point 12 – IS of point 13=1.085 – 1.345= -0.26

13. IS of point 13 – IS of point 14 =1.345-1.355=-0.01

14. IS of point 14 – IS of point 15=1.355-(-2.015)=+3.37

15. BS of point 16 – IS of point 17=1.655-1.685= -0.03

16. IS of point 17 – FS of point 18=1.685-1.455=+0.23

Step.2 - Calculate R.L:

note: (*upward direction sign,rise-ve,fall=ve)

(*downward direction rise+ve,fall-ve)

2. RL of 9 point= 185.635 – 0.53 = 185.105

3. RL of 8 point=185.105+1.42=186.525

4. RL of 7 point =186.525+2.07=188.595

5. RL of 6 point=188.595- 2.74=185.855

6. RL of 5 point=188.855+0.66=185.195

7. RL of 4 point=185.195+0.68=185.875

8. RL of 3 point=185.875-1.44=184.435**

9. RL of 2 point=184.435+0.52=184.955

10. RL of 1 point=184.955+0.25=185.205

11. RL of 11 point=185.635+0.05=185.685

12. RL of 12 point=185.685-0.91=184.775

13. RL of 13 point=184.775-0.26=184.515

14. RL of 14 point=184.515-0.01=184.505

15. RL of 15 point=184.505+3.37=187.875

16. RL of 16 point=187.875-3.32=184.555

17. RL of 17 point=184.555-0.03=184.525

18. RL of 18 point=184.525+0.23=184.755

check:

∑B.S - ∑F.S = ∑RISE - ∑FALL

(7.795 – 8.245 )=( 9.02 – 9.47) =(184.755 – 185.205)

    -0.45         =        -0.45       =       -0.45