DETERMINATION OFQUANTITY OF SEEPAGE UNDER SHEET PILE(FLOW NET ) BY USING VISUAL BASIC PROGRAM

Abstract

This research is empirical method for estimating the quantity of seepage under sheet pile wall, which influence on the stability and durability of the sheet pile.Flow net plotted by using Visual Basic Program, which gives greater number of flow lines and equipotential lines. The comparison between the results of visual program and the field observations explains excellent agreement.Theoretical models (used to determine quantity of seepage) are divided into three broad categories depending on length of clay layer (blanket) in the down stream side (L=0, 2 and 6 m). For each category, the models are divided into six parts depending on the depth of penetration of sheet pile (H3=2, 4, 6, 8, 10 and 12m) for various values of the depth of bed rock (H4=24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4 and 2 m) and various values of total head differences ( h=H1-H2=3, 4 and 8 m).From the results of the program, at constant (H4), the quantity of seepage decreases with increasing (H3), also at a given (H3), the quantity of seepage increase with increasing (H4) and head difference ( h). A rapid decrease in quantity of seepage with increasing clay layer length (L).The mathematical representation of the series of models are represented by empirical equation resulted from a regression analysis by MS-Statistica. The results of the empirical equation are conservative as compared to the results of the experimental work