STUDY ON THREE-DIMENSIONAL PRESSURE DISTRIBUTION BELOW HYDRAULIC STRUCTURES ON PERMEABLE FOUNDATION

Abstract

Percolation of water in porous media unJer hy3raulic structures is one of the important causes which disturbs the stability of the latter. It exerts uplift pressure underneath the foundation and produce exit gradient at the end of the foundation. After years of endeavour in search of natural pheno-menon of percolation and its result, came to arrive at the analytical solution. Many couple d ties, which governs the movement of seepage flow, urges to develop the experimental resolution with the emergence of electrical analogy in early part of present century. This technique solves the problem of seepage flow and force in 2-dir_Zensional as well as 3-dimensional, Three dimensional concept considers not only the main flow of water but also takes the environmental factors into account serving, better result. Little work has been done in this direction, The present study has been conducted by electric analogy, in a 3-dimensional tray for the deten_iination of seepage pressures below the depressed floors and exit gradients in cases where the 3-dimensional seepage is predominant, as suning homogeneous situa-tion. Effect of variation of sheetpile length on pressures and exit gradient is studied with two different depths of depression of floors under four ground-water table conditions, Further investigation was also r_ua1e to study the effect of the water table distance fro._I the structure in the model tray with four varying distances. The results of this study have been coiopared with those for two-Iii_oensional case to reveal the effective-ness of the three-3ii_2ensional flow. This work has been carried. out in an attempt to fill some gap in the wide field. of seepage study.