From the constructed flow net in the present experimental research paper, an attempt has been made to analyze, determine and present the following parameters: - 2113 - 2) Numerical solution based on parabola Numerical Solution Dupuit Solution Modified Laplace equation Assumes: a) Flow lines to be nearly horizontal b) Hydraulic gradient of the flow is equal to the slope of the phreatic surface x y i � a brief review is presented of many possible applications of the flow-net to earth dam and levee design suggesting some techniques of constructing flow-nets, particularly those having an indeterminate phreatic line. In Fig.6.3(b), a transformed section and a flow net thus drawn for the case kh=9kv is presented. 2.1 FLOW NET. The seepage is given by: q=kh 4-7 = x x = 3-1 x 10-5m3/s (per m) The pore water pressure is calculated at the points of intersection of the equipotentials with the base of the dam. The position of the phreatic line influences the stability of the earth dam because of potential piping due to excessive exit gradient and sloughing due to the softening and weakening of the soil mass as if it touches the downstream slope or intersects it. The true flow net In order to achieve these objectives, an experimental flow net system inside the body of a homogeneous earth embankment dam model was formulated by using a drainage and seepage tank. Figure 1 shows an example of flow net construction. An earth dam constructed without a cutoff on permeable or semi-permeable foundations of earth or rock may lead to seepage beneath the dam creating unacceptable uplift pressures and causing instability.

In the flow net there are 4-7 flow channels and 15 equipotential drops. Flow nets are applicable for the study of cutoff walls and wellpoints, or shallow drainage installations placed in a rectangular layout whose length in plan is 1 Réseaux d'écoulement .

flow of water through soil masses is but one of the number of forms of stream-line flow that can be studied with the flow-net. Use this procedure to estimate seepage quantity and distribution of pore water pressures in two-dimensional flow. An earth dam constructed without a cutoff on permeable or semi-permeable foundations of earth or rock may lead to seepage beneath the dam creating unacceptable uplift pressures and causing instability. If an impermeable cutoff is installed to 60 % of the depth of the permeable foundation, the flow net and downstream slope gradient is only slightly modified to a lower level. Soil Mechanics Flow Nets page 2 Drainage blanket Phreatic line Unsaturated Soil z Flow of water x Fig. Draw trial flow net See Cedergren Seepage Drainage and Flownets – posted on web. use of flow-net in earth dam and levee design.

If an impermeable cutoff is installed to 60 % of the depth of the permeable foundation, the flow net and downstream slope gradient is only slightly modified to a lower level. In order to draw a flow net for such a dam, the horizontal scale of the dam is first reduced by multiplying a scaling factor (kh/kv) 0.5 and a flow net is constructed assuming that the medium is isotropic. Flow Nets 1 10.1 Introduction Let us consider a state of plane seepage as for example in the earth dam shown in Figure 1. Chapitre 10.