Q1. Using the data given for the compound curve shown in figure 11-22, compute the stations at PC1, PI1, PCC (point of compound curvature), PI2, and PT2.

Q3. Assume that you are to set half stations for a 400-foot symmetrical vertical curve. The tan-gents

intersect at Station 14 + 00. The tangent elevation at the PVI is 131.20 feet. Compute the following information for this curve:

Q4. Assume that you are to set half stations for a 600-foot vertical curve. The tangents (g1 = 3 percent, g2 = 8 percent) intersect at Station 15 + 00, which has an elevation of 640 feet above mean sea level. You may also assume that l1 = 400 feet and l2 = 200 feet. Compute the following information for this curve:

d. Grade elevation on the curve at station 13 + 50

e. Station number and grade elevation on the curve at the turning point

A1.Station at PC1: 19 + 11.71
Station at PI1: 23 + 84.28
Station at PCC: 27 + 68.85
Station at PI2: 29 + 66.62 
Station at PT2: 31 + 43.85

A4. (A) 124.80 feet, (B) 128.00 feet, (C) 128.80 feet, (D) 128.25 feet, (E) Station 14 + 67, elevation on tune equals 129.0 feet.

A5. (A) 652.00 feet, (B) 624.00 feet, (C) 636.67 feet, (D) 643.20 feet, (E) Station 11 + 00, elevation = 652.00 feet. (The turning point is the high or low point on a vertical curve. When the tangent grades are equal, the high or low point will be at the center of the tune. When the tangent grades are both plus, the low point is at the PVC and the high point is at the PVT. When both tangent grades are negative, the high point is at the PVC and the low point is at the PVT. When unequal plus and minus tangent grades are encountered, the high or low point will fall on the side of the curve that has the flatter gradient.)