How can we solve the ground reaction?

Discussion in 'All Things Boats & Boating' started by xichyu, May 1, 2016.

  1. xichyu
    Joined: Apr 2016
    Posts: 99
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: Dalian,Liaoning,China

    xichyu Junior Member

    A ship stranded on a shoal,and part of hull under sea mud. The weight of ship
    is G. If we only know the shiplines,other details can not be obtained. How can
    we solve the ground reaction?
     
  2. TANSL
    Joined: Sep 2011
    Posts: 6,494
    Likes: 390, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    G = Ground reaction + thrust due to the volume of displaced water.
    Sum of moments of the three forces = 0. It will be more difficult to determine.
     
  3. Barry
    Joined: Mar 2002
    Posts: 1,401
    Likes: 221, Points: 63, Legacy Rep: 158

    Barry Senior Member

    I think that it will be a little more complicated than the above due to the fact that the mud would provide some buoyancy.

    ie if the boat was grounded on rock, it would be quite simple if you knew the amount of water displaced.
    But in this case if the mud is soft then there will be pressure/buoyancy on the hull acting below the mud to water interface.

    So if it is quite soft then you would have to determine the amount of mud that is also displaced and determine buoyant forces using the density of the mud

    Alternatively if you had scoured out the profile of the hull into the mud to some level and let the boat strand into the scoured out profile, you would still get a buoyant effect from the volume of the water displaced by the hull below the mud level if the boat hull surface was wet.
     
  4. gonzo
    Joined: Aug 2002
    Posts: 15,149
    Likes: 910, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    It would largely depend on the qualities of the mud. You should treat it like a semi-solid.
     
  5. TANSL
    Joined: Sep 2011
    Posts: 6,494
    Likes: 390, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    You will agree with me that in the "Ground reaction" is included buoyancy due to mud.
    On the other hand, with the data that the OP gives us, it seems quite impossible to draw any meaningful conclusion.


    What is very important is to know that: "It would largely depend on the qualities of the mud". With that and a fishing rod, we can solve the problem.:)
     
  6. xichyu
    Joined: Apr 2016
    Posts: 99
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: Dalian,Liaoning,China

    xichyu Junior Member

    Yes,I am considering to learn Soil Mechanics
     
  7. xichyu
    Joined: Apr 2016
    Posts: 99
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: Dalian,Liaoning,China

    xichyu Junior Member

    TERZAGHI EQUATION may solve the problem
     
  8. xichyu
    Joined: Apr 2016
    Posts: 99
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: Dalian,Liaoning,China

    xichyu Junior Member

    In the initial stage, we can assume the same qualitiy of the mud
     

  9. gonzo
    Joined: Aug 2002
    Posts: 15,149
    Likes: 910, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The Bowles correction could be used giving Dw=0. That is an interesting approach
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.