1 . A symmetrical parabolic summit curve connects two grades of + 6% and-4%. It

Question

1 . A symmetrical parabolic summit curve connects two grades of + 6% and-4%. It is to pass through a point P the stationing of which is 35 + 280 and the elevation is 198 130m, The elevation of the grade intersection is 200.000m with stationing 35+300. Determine a. The length of curve. b. Stationing of PC c. Stationing of PT d. Elevation of PC e. Elevation of PI f. Elevation of the highest point on the curve. g. The location of the highest point on the curve h. Elevation of station 35+260 on the curve.

Explanation / Answer

Here,

N1 = 6% and N2 = - 4%

N = N1 - N2

= 6 - (- 4 )

= 10%

Parabolic curve equation gives

y = (2 x2 )÷( N w )

Here,

200 - 198.130 = 1.87 ( value of y )

x = w÷2

Using equation of parabola

We get,

w = 22.44

Now

(a) length of curve = N÷yXw

=10÷1.87 X 22.44 = 120 m

(b) stationing of PC

280 - 60 = 220m

(35 + 220 )

(c) stationing of PT

280 + 120 =400

(35+400)

(d) elevation of PC

140m

(e) elevation of PT

260m

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.