Seepage flow is well recognized in engineering especially in geotechnicalengineering practice such as dams, slopes, underground spaces, etc.). Seepage passes through soils, rocks and very influenceon the deformation and stability of soils, rocks and geotechnical structures.
Seepage control is crucial for maintaining the stability and safety of theengineering works The physical mechanisms and theircorresponding numerical modeling approaches of engineering measures for seepagecontrol should be understood as they are absolutely important for safetyassessment, optimization design, construction and operation of a seepagecontrol system. We can generally classified engineeringmeasures that have been widely taken for seepage control in geotechnical andgeo-environmental engineering practices into four categories. The very fisrtcategory is the construction of an impervious zone with low permeability andhigh critical hydraulic gradient to limit the quantity of seepage flow, reducethe pore water pressure, and preserve the geometrical integrity of theimpervious system, such as clay core, asphalt-concrete core, concrete face slabor impervious blanket in embankments, grouting curtain in rock foundations, etc? The secondcategory make use of filter and drain zones in soil/rock foundations,underground caverns and concrete/soil dams to decrease pore water pressuremainly the uplift pressure, receive and remove seepage water, and prevent soilsfrom seepage failure, such as drainage holes or horizontal drainage blankets.
The third category is regarding the operation and management of the reservoir,such as the control of the effect of water level fluctuation on groundwatermovement. The last one is to improve, by various groundwater remediationtechniques, the quality of polluted or contaminated water that may causehazards to environments and society. In fractured porous media, themovement of groundwater is governed by the mass and the momentum conservationlaws of water, with the later commonly being represented by Darcy’s law, andsubjected to the constraints of initial conditions, boundary conditions,material properties and computational requirements when numerical modeling isneeded.
Theoretically, by changing, adding or removing the storage terms in thegoverning equation, changes of the initial and boundary conditions, or changesof the hydraulic properties ,the seepage flow process will undergo changes asthe process occurs. Thus, it is utmost important to fully clear with thephysical mechanisms of various engineering measures for seepage control bylinking the control effects with corresponding components in the mathematicalmodel of seepage flow.With that establishment of performance assessment andoptimization design of the seepage control structures could be achieved on amore rigorous mathematical basis and a sounder scientific foundation.