Problem (1)

Given the following information:

Δ = 45°49'45"
D = 07°09'43.1"
L = 693.90 ft
T = 338.17 ft
LC = 622.97 ft

 

Curve Table

  Station di, ft   δi   ci, ft  
EC Back 57+24.88 639.90 = L 24°54'52" = Δ/2 622.97 = LC
  57+00 615.20   22°01'26"   599.99  
  56+00 515.02   18°26'34"   506.18  
  55+00 415.02   14°51'43"   410.38  
  54+00 315.02   11°16'51"   312.99  
  53+00 215.02   7°42'00"   214.38  
  52+00 115.02   4°07'08"   114.92  
  51+00 15.02   0°32'17"   15.02  
BC 50+84.98 0.000   0°00'00"   0.000  

 

Determine curve point coordinates.

Compute azimuth of incoming tangent

Compute coordinates of BC and EC

Set up the azimuth and coordinates equations

Using the az and coord equations, step through the table for each curve point

  Station Azi Ni, ft   Ei, ft  
EC Back 57+24.88 107°54'23" 1274.07 check 10,161.38 check
  57+00 110°47'26" 1273.15   10,136.51  
  56+00 114°22'40" 1277.25   10,036.66  
  55+00 117°57'32" 1293.78   9,938.10  
  54+00 121°32'24" 1322.46   9,842.37  
  53+00 125°07'15" 1362.85   9,750.96  
  52+00 128°46'07" 1414.32   9,665.30  
  51+00 132°16'58" 1584.39   9,834.78  
BC 50+84.98 132°49'15" 1486.18   9,575.62  

 

Problem (2)

For the following short alignment data:

What are the coordinates of curve station 20+00.00?

Partial answers - computations are left to the reader.

NPI = 1151.53 ft
EPI = 1131.30 ft
NBC = 1052.74 ft
EBC = 589.35 ft
δ20+00 = 14°07'03"
c20+00 = 698.76 ft
Az20+00 = 93°47'13"
N20+00 = 1006.59 ft
E20+00 = 1286.58 ft

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