## Tuesday, September 2, 2014

### Structural analysis for vertical concrete canal linings

Assumptions:
1. No water inside the canal and the embankment outside
is up to the top bank of the canal.
2. Soil is saturated.

Procedure of analysis:

1. Compute for pressure at canal bottom using the formula:
(1-sin(A))
Ph = ----------- x SoilWeight x CanalHeight
(1+sin(A))
A = Angle of internal friction of soil

2. Compute for total shear on the wall:
Ph x Canalheight
Vh =     ----------------
2

3. Compute for Moment @ Canal bottom
Vh x CanalHeight
Mh = ------------------
3
4. Compute for total Weight of Canal per 1-m strip (Wcanal).

5. Compute for soil bearing pressure assuming soil bearing
capacity is sufficient.
Wcanal
Pb = ---------------------
Canal Gross Width (W)

6. Compute for weight of canal flooring (Wslab)
Wslab = 2,400 x FloorThickness(t1)

7. Compute for uplift due to water pressure.
Wuplift = 1,000 x (CanalHeight + t1)

8. Net upward force acting on the canal bottom
Pv = Pb - Wslab + Wuplift

9. Compute for shear at slab support
Pv x CanalBase
Vv =       --------------
2

10. Compute for Moment at Support
Pv x CanalBase^2
MvNeg =       ----------------
12

11. Compute for Moment at Midspan
Pv x CanalBase^2
MvPos =        ------------------
24

12. Using these moments, you can now compute for the
required steel reinforcements then compute
the required spacings.
M
As = -------
fs x j x d

* Assuming d is half of the member thickness or depending on your
decision whether where to put the reinforcements.

#### 1 comment:

1. pahingi ng serial code alex. thanks..........elmer b. felisarta