1) Determine the drainange basin area, time of concentration (B-W), 5 year storm intensity and
peak runoff for the following point of analysis. Assume the 5% of the area is impervious, 10% is
cresidential and the remainder is forested over loam soils.
Stationing and Chainages
Chainage/Stations are points along a baseline used to indicate
distances along this line, either from the start point (0+00) or between
points. An example of such a baseline is the centre line (C/L) of a
road (i.e. centre line).
Turbulent Flow and Energy
Under ordinary pipe flow circumstance energy loss occurs due
Friction against pipe wall
Turbulent flow has a higher velocity gra near the wall leading to
Turbulent flow also has more momen
Empirical Equations for Friction Loss
There are three formulas that can be u calculate head loss (h f):
Hazen Williams Formula
HazenWilliams equation was develope experimental
The art of measuring distances and angles on or near the
surface of the earth.
What do surveyors do?
Take measurement of distances (horizontal, slope and
vertical), angles (horizontal and vertical) and positions.
Describes the refi
Manning equation is another popular experimental
formula fo openchannels and pipes.
Manning equation is mathematically shown as:
V = (1/n)R2/3S1/2
V = (1.486/n)R2/3S1/2
Where: V = Velocity of flow
(m/s or ft/sec)
Construction Project Process
This is done in field to layout what was created in
the design phase
Horizontal Control Points are used to layout the
horizontal locations of features footings, building
corners, lines for columns/support beam
Municipal Road Construction
Plan and profile:
The proposed feature(s) must be built so that it meets the horizontal and vertical
specifications accurately and precisely.
In other words:
The blueprint (Design Plan/Layout Plan) describes exactly what must
Entrance to a pipe from large reservoir is a common of a pipe
Head loss at entrance of a pipe is calculated as:
Head Loss due to Pipe Expand
Similar to the previous slides discussion regarding pi contraction
there are three comm
Is the ratio of error of closure to the distance
Example: a distance was measure and found
ft. The distance was previously known to
ft. The error is 0.06 ft in a distance of
ft. What is the accuracy