A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
The saturation of agricultural soil may be caused by either or both of the following reasons: (1) over-irrigation or rain; and (2) seepage from a nearby river, canal, or irrigated field.
Case (1) will be investigated herein. The downward seepage flow through porous soil to a system of parallel tile drains is studied, 2nd a theory of hydrodynamics is developed with the object of providing a scientific basis for the design of tile drains.
Because the seepage flow takes place in planes at right angles to the parallel system of drains, the problem is treated as being two-dimensional. Complex function theory and conformal mapping are used to derive relations among the discharge, head, and spacing of tiles.
The unsteady nature of the seepage flow is taken into account because the water table rises to a maximum height after irrigation or rain, and then falls gradually due to the influence of drainage. A new spacing formula is obtained that is based on the time variation of the water table. This formula gives more economical designs than most of the existing formulas.
The effect of evaporation from the soil surface on the spacing formula is then introduced. This effect alone produces an additional economy of approximately 50%. An actual drainage problem is solved by application of the present theory and then compared with solutions derived by use of the theories of other investigators.
The saturation of agricultural soil may be caused by either or both of the following reasons: (1) over-irrigation or rain; and (2) seepage from a nearby river, canal, or irrigated field.
Case (1) will be investigated herein. The downward seepage flow through porous soil to a system of parallel tile drains is studied, 2nd a theory of hydrodynamics is developed with the object of providing a scientific basis for the design of tile drains.
Because the seepage flow takes place in planes at right angles to the parallel system of drains, the problem is treated as being two-dimensional. Complex function theory and conformal mapping are used to derive relations among the discharge, head, and spacing of tiles.
The unsteady nature of the seepage flow is taken into account because the water table rises to a maximum height after irrigation or rain, and then falls gradually due to the influence of drainage. A new spacing formula is obtained that is based on the time variation of the water table. This formula gives more economical designs than most of the existing formulas.
The effect of evaporation from the soil surface on the spacing formula is then introduced. This effect alone produces an additional economy of approximately 50%. An actual drainage problem is solved by application of the present theory and then compared with solutions derived by use of the theories of other investigators.
Depth and Spacing of Tile Drain Systems
Hammad, H. Y. (author)
Transactions of the American Society of Civil Engineers ; 128 ; 535-554
2021-01-01
201963-01-01 pages
Article (Journal)
Electronic Resource
Unknown