الهندسة الجيوتقنية

Seepage ‘Seepage’ is defined as the flow of a fluid, usually water, through soil under a hydraulic gradient. A hydraulic gradient is supposed to exist between two points if there exists a difference in the ‘hydraulic head’ at the two points. Hydraulic head is meant the sum of the position or datum head and pressure head of water. The discussion on flow nets and seepage relates to the practical aspect of controlling groundwater during and after the construction of foundations below the groundwater table, earth dam, and weirs on permeable foundations. Flow Net The flow lines indicate the direction of flow and equipotential lines are the lines joining the points with the same total potential or elevation head. From upstream to downstream, the total head steadily decreases along the flow line. A network of selected flow lines and equipotential lines is called flow net A flow net is a graphical solution to the equations of steady groundwater flow. A flow net consists of two...

SHEET NO. 6 1)      What are the conditions necessary for Darcy’s law to be applicable to the flow of water through the soil ? 2)      Explain the meaning of the term ‘‘ Seepage pressure’’. 3)      Write short notes on Quicksand Conditions, 4)      Define the coefficient of permeability of soils. 5)      Define the discharge velocity and the seepage velocity. Drive the relationship between the two velocities in terms of soil`s porosity. 6)      Why is the capillary rise greater for fine-grained soils than for coarse-grained soils? 7)       What are the factors affecting the permeability of soils? 8)      Compare between the constant head and variable head permeability tests. 9)      Describe clearly with a neat sketch of how you will determine the coefficient of permeability of a clay ...