Tte 42035805 - advanced highway geometric design the pi of

Question

Advanced Highway Geometric Design

Problem 1 - Two tangents intersect at station 37+63.82 with a central angle, Δ, of 15^o37'30" Rt. A 02^o30'00" circular curve connects the two tangents.

(a) Draw the circular curve layout and calculate the following: R, T, PC, PI, PT, Δ, L, LC, M and E.

(b) Calculate the deflection angle from the PC to station 38+00.

Problem 2 - The PI of two tangents of a highway is located in a lake. Station A and B are selected to replace the inaccessible PI.

(a) What is the radius of the circular curve between the PC and PT?

(b) What is the degree of the curve?

(c) What is the length of the curve?

(d) What is the station of the PT?

(e) If the instrument is at the PC, what deflection angle should be used to locate staking station 116+00 on the curve?

(f) If the instrument is at the PC, what deflection angle should be used to locate staking station 117+00 on the curve?

(g) If the instrument is at station 116+00, what deflection angle should be used to locate staking station 118+00 on the curve?

Problem 3 - An existing 6^o curve connects PC and PT' as shown. It is desired to avoid having vehicles pass close to an historical monument, so a proposal has been made to relocate the forward tangent 100 ft parallel and inward. The PC will remain in the same place. What is the new PT₂ station?

Problem 4 - Two tangents intersect as shown. Due to a realignment of the roadway, the forward tangent will be angled inward requiring a compound curve to be constructed. The PI is at station 74+65.00.

For the information given:

(a) Determine Δ₂.

(b) Determine the new PT station.

Problem 5 -A freeway is being constructed near an existing USGS survey monument. The tangent alignments are shown, although the freeway can be on either side of the monument. The freeway has a 75 ft right-of-way on either side of the curve centerline. USGS monument law requires a 1-foot clearance from the monument (which is considered to be a dimensionless point) to the edge of the right-of-way. Find the range of radii of circular arcs that will provide the required clearance. (Hint: the clearance is radial, measured along a line from the curve center of the monument.)