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

    ReplyDelete