## Groundwater flow analysis

### SEEP/W analyzes groundwater flow within porous materials. Its formulation enables analyses ranging from simple saturated steady-state problems to sophisticated saturated/unsaturated time-dependent problems.

SEEP/W can be applied to the analysis and design of geotechnical, civil, hydrogeological, and mining engineering projects.

### Boundary Conditions

SEEP/W supports a range of boundary condition options. Field data or user-specified functional relationships can be inputted to define hydrographs, reservoir fluctuations, rainfall cycles, or anything imaginable.

### Integration

Integration of SEEP/W with SLOPE/W makes it possible to analyze the stability of any natural or man-made slope subject to transient changes in pore-water pressure.

### Material Properties

Hydraulic conductivity and volumetric water content functions can be estimated using built-in functions. The estimation process requires only fundamental information. A Saturated-only material model is also available.

### Saturated Unsaturated

The rigorous saturated-unsaturated formulation of SEEP/W means that even the most demanding flow problems, such as infiltration into dry soil or seepage through complex upstream tailings dams, can be analyzed with ease.

### Modeling Drains

This example illustrates how to model the effect of a drain in a seepage analysis. Modeling the effect of a drain with the specification of a total head type boundary condition at a point is more than adequate for small drains, and is a useful approach to get a first estimate of the flow quantities one might expect.

### Perched Water Table

This example demonstrates how to use SEEP/W computed pore-pressures in a SLOPE/W stability analysis. The problem creates a perched watertable under long term net infiltration of precipitation. This perched condition can only be properly handled by directly using the SEEP/W results in SLOPE/W.

### Seepage Through Embankment

This example looks at a case of flow through an embankment dam. This case appears in most text books on seepage and consequently most SEEP/W users will have a good idea as to what the solution should look like. The example illustrates how easy it is to find the downstream seepage face when the dam is all one material.

### Verification: Infiltrated Dry Soil

Infiltration into unsaturated soil is of great interest in hydrology, soil science, agricultural science, and geotechnical engineering. This example benchmarks SEEP/W against a semi-analytical solution for one-dimensional infiltration in unsaturated soil developed by Warrick et al. (1985).

Draw the regions in your domain using CAD-like drawing tools, including drawing polygon and circular regions, coordinate import, copy-paste geometric items, length and angle feedback, region splitting and merging, and direct keyboard entry of coordinates, lengths, and angles. Alternatively, import AutoCAD DWG or DXF files directly into GeoStudio to create your domain geometry.

Define the material properties for your analysis, assign them to regions on the domain, and then define your initial pore-water pressure conditions. Select from Saturated/Unsaturated, Saturated Only and Interface material models. Define hydraulic material functions using spline data point entry, Fredlund-Xing or van Genuchten methods. Define the initial pore-water pressure conditions for transient scenarios using results from other SEEP/W analyses, defined spatial functions or draw an initial water table.

Define hydraulic boundary conditions to simulate total head, pressure head, pore-water pressure, unit flux (q) or total flux (Q) conditions. Time-varying conditions can also be modeled using total head, pressure head, unit flux (q) or total flux (Q) vs. time functions. The total head vs. volume function can also be used to simulate volume of water entering or exiting the domain via a specified boundary.

When the Solver is finished, the Total Head contours are displayed, along with the location of phreatic surface, or zero pressure isoline, and flux vectors. You can display other contours of almost any parameter including pore-water pressure, material properties, water flow, and gradients, using the Draw Contours window. Contour legends and properties can also be modified. Labels can be added to contour lines for display in Results View. Flow paths can also be drawn in steady-state analyses.

Interactively select any node or gauss region to view result information, including total head, pore-water pressure, material properties, and more. Display plots of computed results over the x- or y-direction or create time-varying plots of results in transient analyses, such as total head, water flux, cumulative water volume, and more. Generate reports of the definition and results, and export into other applications such as Microsoft Excel for further analysis.

## The power of integration

### SEEP/W offers simple but powerful analytical capabilities when used in combination with other GeoStudio products.

### SEEP/W results in SLOPE/W

Using SEEP/W finite element pore-water pressures in SLOPE/W makes it possible to deal with complex saturated/ unsaturated conditions or transient pore-water pressure conditions. From a transient analysis, we know the pore-water pressure conditions at various points in time. Using these time- varying pore-water pressure results in SLOPE/W makes it possible to look at the changes in stability with time.### SIGMA/W coupled with SEEP/W

SIGMA/W essentially solves equations of equilibrium while SEEP/W solves equations of continuity. A consolidation analysis solves both sets of equations simultaneously and results in both deformation and pore-water pressure changes with time. Running SIGMA/W and SEEP/W at the same time makes it possible to do fully coupled consolidation analyses.### SIGMA/W pore-water pressures in SEEP/W

Excess pore-water pressures generated during any kind of loading (fill placement, for example) can be taken into SEEP/W to study how long it will take for the excess pore-water pressure to dissipate. This can help with specifying the rate of loading.

### QUAKE/W results in SEEP/W

The QUAKE/W computed excess pore-water pressures generated during an earthquake can be taken into SEEP/W to study how long it will take for the excess pore-water pressure to dissipate.### Convective Heat Flow

TEMP/W can use the water fluxes from SEEP/W to model forced-convection heat transfer.

### SEEP/W results in CTRAN/W

One of the major components in a contaminant transport analysis is the velocity of the water, which can be obtained from a SEEP/W analysis. Once this velocity is known, it can be used in CTRAN/W to study the transport of contaminants.

**Density-Dependent Flow**

** **

In density dependent fluid flow, the density of the water is dependent on the solute concentration. The water velocity in turn influences the movement of the solute. SEEP/W and CTRAN/W therefore need information from each other. The iterative transfer of water velocity from SEEP/W to CTRAN/W and the transfer of concentration from CTRAN/W to SEEP/W makes it possible to do density dependent fluid flow analyses.

### Couple AIR/W with SEEP/W

Coupled air-water systems can be modeled with SEEP/W and AIR/W. The two systems are coupled via the matric suction, which is the difference between the pore-air and pore-water pressures. A change to the air pressure will cause a change in the water pressure and vice versa. This type of analysis can be useful for modelling mine closure cover systems or water/air movement in acid generating waste rock.