by Van der Schrieck
Understanding the world of sand and water
This book is nr 2 of a series on Dredging Technology. As a Reference Guide the book contains the basic theories and formula's that a project engineer needs to know when he is involved in Dredging Projects as a Client or Contractor.
It is a quick and compact reminder of theories and formulas relevant for project preparation, - execution and handling of possible claims. For a more extended and broad insight reference is made to the authors main text book "Dredging Technology Book 1".
This guide covers the following subjects:
- Basic soil mechanics relevant for any dredging project;
- Soil stability of retaining walls and quick sand condition;
- Compaction and Dilatancy governing slope stability and cutting forces;
- Basic Fluid Mechanics;
- Concentrations and Density when pumping soil and water;
- Parameters of water jets;
- Formula's for pump production calculations such as Degree of Loading of a Hopper-dredge;
- The stability of a pontoon and calculation of the metacentre height;
- Theory of a Centrifugal Dredge Pump and the effect of the pump drive;
- Impact of a diesel drive on a centrifugal pump characteristic;
- Effect of the pipeline length on the working point and effectiveness of the drive;
- Effect of a change in the pumpimpellar diameter or a change in the gear ratio;
- The suction process, the vacuum, the limiting vacuum and cavitation at the pump entrance; This is the most important part of the hydraulic transport process when using a suction dredger, since it is the starting point of the soil volume production in cubic meter per hour;
- The vacuum production is analysed resulting in an optimisation of the suction production;
- A compact description of the electric generator and motor;
- Difference between DC and AC;
- The three phase alternating current motor and the principle of the "Electrical Shaft";
- Production formula' s for a cutter suction dredger and a trailing suction hopper dredger.