Cross section 4+50
Talking about "Real Problems" I thought this might be
interesting. Below is data that will plot two lines, that
are plans for a dam to be constructed. The first of each
data point is an elevation (feet), the second is the distance
(feet) from the dam center line. Negative distances are on the
left. So these are y and x when plotting. The survey is
taken before the design, of course. Then from the design
we get a template to overlay the survey. The next step
is to compute the dam cross section area and the centroid
of the area.
1. What is cross section area?
2. What is the (Elev, Dist) centroid?
3. What we use would the centroid for?
Survey
Station 450
========================
687.05___-136.98
680.43____-61.62
677.47____-29.93
676.04______0.00
675.44_____18.60
671.13_____31.57
664.73_____58.17
661.83_____90.89
657.3_____103.84
654.79____113.55
658.54____129.44
662.13____140.12
663.34____165.83
=====================
Dam Template
680.92___-67.23
700.00___-10.00
700.00_____0.00
700.00____10.00
678.00____76.00
678.00____96.00
662.27___143.18
interesting. Below is data that will plot two lines, that
are plans for a dam to be constructed. The first of each
data point is an elevation (feet), the second is the distance
(feet) from the dam center line. Negative distances are on the
left. So these are y and x when plotting. The survey is
taken before the design, of course. Then from the design
we get a template to overlay the survey. The next step
is to compute the dam cross section area and the centroid
of the area.
1. What is cross section area?
2. What is the (Elev, Dist) centroid?
3. What we use would the centroid for?
Survey
Station 450
========================
687.05___-136.98
680.43____-61.62
677.47____-29.93
676.04______0.00
675.44_____18.60
671.13_____31.57
664.73_____58.17
661.83_____90.89
657.3_____103.84
654.79____113.55
658.54____129.44
662.13____140.12
663.34____165.83
=====================
Dam Template
680.92___-67.23
700.00___-10.00
700.00_____0.00
700.00____10.00
678.00____76.00
678.00____96.00
662.27___143.18
posted by Ragknot at
2:33 PM
4 Comments:
A=3380.781 ft^2
Ax=126157.5
Ay=2294132
centroid
x=37.31607
y=678.5804
The weight of the dam acts at the point of the centroid.
Easiest to calculate reactionary forces of dam to different water loads if this centroid is known.
Cam
2 out of 3 not bad at all
Your computations are right on.
I didn't think anyone would try this.
The X centroid value is used to compute the volume in the curve the dam. Since the dams are mostly horizontal along the stations, the Y centroid is not used in earth structures. Earth dams are so wide the vertical is not of much interest.
If the dam was straight, then we don't use the X either.
Great job.
Kick last post
Dam Section 4+50
Post a Comment
Links to this post:
Create a Link
<< Home