Seepage rates

Molten sufur may tend to migrate within certain mixes, analogous to bleeding in cement concrete, so it is essential to exercise care in mix design to minimize seepage. A test method is currently being developed to measure sulfur seepage rates in mixes. 

Abstract This paper examines the hydraulic interaction between emplaced engineered clay buffers and host rock formations. This has been achieved via the analysis of the re-saturation behaviour of a large scale in-situ experiment. Experimental results from a testing programme performed by Atomic Energy of Canada Limited, (AECL), are examined via both direct interpretation of the experimental results and numerical simulations of the test. Analysis of seepage rates into an open borehole indicate the presence of an EDZ prior to the emplacement and some healing of the EDZ after buffer placement. It is also found that correct representation of moisture infiltration into the buffer is essential to capture the variations in pore water pressure in the host rock. 

Analysis of seepage rates of the first and last phases of the experiment, when the borehole is open, tend to indicate that prior to the emplacement of the buffer material flow towards the borehole was increased due to the presence of an EDZ. Also, seepage after the buffer had been removed was reduced indicating some healing of the EDZ had occurred. 

Figure 5 Seepage rates at Waquoit Bay, Massachusetts, USA, measured using a dye dilution automated seepage meter. Modified from Sholkovitz ER, Herbold C, and Charette MA (2003) An automated dye-dilution based seepage meter for the time-series measurement of submarine groundwater discharge. Limnology and Oceanography. Methods 1 17-29.

Apart from an increase in the mean velocity, the other factors that cause deviations from the linear laws of flow include the non-uniformity of pore spaces, since differing porosity gives rise to differences in the seepage rates through pore channels. A second factor is the absence of a running-ln section where the velocity profile can establish a steady state parabolic distribution. Lastly, such deviations may be developed by perturbations due to jet separation from wall irregularities. 

Using their theoretical flow net and experimentally determined coefficient of permeability students then compute the seepage rate from standard theory using ... 

The movement of groundwater to and from surface water can range from slow, diffusive seepage across large areas of sediment beds to rapid, concentrated flows at specific locales. Four methods are commonly used to determine these seepage rates, they are (1) water balance, (2) hydrographic analysis, (3) hydraulic-conductivity and... 

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