Review of Midterm Quiz 2 Content -- Like midterm Quiz 1, this quiz will be 20 questions with about 6 or 7 questions from each topic.
Questions:
6 or 7 questions -- Spirals, half conceptual/theory, half computation. All will be in the SR 25 context.
6 or 7 questions -- Superelevation theory and comps
6 or 7 questions -- Quantities and earthwork analysis.
Total 20 questions
Subjects:
Spirals – concept of the need for and use of spirals, spiral parts Rc, Ls, DELTAs, r, l, little DELTA, Xs, Ys, throw P, K, LT, ST, LC, inserting spirals into an alignment, shifting the circular curve, DELTAc, Lc, stationing the spiraled curve, designing spirals to prevent overlaps (approx half spiral length inside/outside of original PC/PT).
Sample calcs: Given Rc and a spiral length Ls, what's DELTAs, Xs, Ys, throw, the length of remaining circular arc, etc. Also, what's the largest Ls that will avoid spiral overlaps between Curves 1 and 2? Given a "jerk" C, what's the required velocity, radius, Ls, etc.
Superelevation – concept of the need for superelevation, quantity e, superelevation equation, side friction factors (max, safe, design), superelevation e (max, design), rate of rise ROR, Length of Transition, AASHTO chart, superelevation transitions, pavement edge vertical offsets, pavement edge elevations, edge profiles.
Sample calcs: Compute the baseline's "profile grade" including vertical curves. What's the f value for vehicles at various velocities? Calculate or state V/f/e in various stated conditions: equil, safe, max, and design on SR25, compute Rmin for a design speed.
Earthwork Analysis – a quantity sheet, pay items of construction, four traditional line items for earth operations, roadway excavation, overhaul compensation, borrow, waste, free haul distance, limit of economic haul, constructing a mass diagram, shrinkage factors, expand fills, compute earthwork cumulative total, plot mass diagram, make a schematic profile for analysis, apply FHD balance lines, identify cut and fill quantities Q's, tabulate line item quantities, compute total earthwork costs.
Sample calcs: Compute SR25 transition stations between cut/fill, compute SR25 earthwork volumes, apply shrinkage factor, compute cumulative volume values by station, plot mass diagram. Apply FHD balance lines, determine $a quantities (Q's). Compute LEH, apply LEH balance lines, compute $c overhaul compensation. Identify and compute borrow excavation at $b and waste excavation at $d. Given alternate values of FHD, and $a/b/c/d, what are the various quantities – LEH, r'dwy exc, overhaul, borrow, waste, costs of each? Also identify critical places on the mass diagram and profile – max depth cut/fill, points of inflection, transitions from cut/fill, etc.