1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Pore pressure due to capillary rise

  1. Sep 14, 2017 #1
    1. The problem statement, all variables and given/known data
    Why there's no pore pressure due to capillary rise at point A and point D ? There's only pore pressure due to capillary rise at B ..
    2. Relevant equations


    3. The attempt at a solution
    i think the author is wrong . There's should be also ore pressure due to capillary rise at A and D . Because the capillary rise can occur anywhere in the soil .
     

    Attached Files:

    • 678.PNG
      678.PNG
      File size:
      13.5 KB
      Views:
      10
    • 679.PNG
      679.PNG
      File size:
      10.9 KB
      Views:
      12
    • 680.PNG
      680.PNG
      File size:
      71.6 KB
      Views:
      15
    • 681.png
      681.png
      File size:
      42.9 KB
      Views:
      14
  2. jcsd
  3. Sep 14, 2017 #2
    Can you please define the variables in your equations.
     
  4. Sep 14, 2017 #3
    Huh , what do you mean ?

    It's the pore water pressure due to capillary rise , u = -s(yw)(H2)
     
  5. Sep 14, 2017 #4
    There is no water in the pores at A; it is above the saturation zone. At D, the pores are all fully saturated, because it is below the water table, and there is no capillary pressure there because there is no free surface (between air and water) in this zone. So the author is correct.
     
  6. Sep 14, 2017 #5
    Having said that there's capillary rise at B , means that there is free surface (between air and water) in this zone ?

    I didnt see there's air at B , can you explain further ?
     
  7. Sep 14, 2017 #6
    Sure.
    What do the words "50% saturated" mean to you?
     
  8. Sep 14, 2017 #7
    ok , noted . Why there is no pore pressure due to capillary rise at C ?
     
  9. Sep 14, 2017 #8
    At C and below, the pores are completely full of water.
     
  10. Sep 15, 2017 #9
    How do you know that there's no water at A ? How do you know that there's water at B ?
     
  11. Sep 15, 2017 #10
    The figure implies that, between A and B, there is dry sand and between B and C, there is partially saturated sand. So, B is the top of the region containing water in some of the pores.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Pore pressure due to capillary rise
  1. Rise of a piston (Replies: 1)

Loading...