ISSN:
1432-0495
Keywords:
Key words Effective porosity
;
Specific yield
;
Migration
;
Tracer test
;
Porosity
;
Tritium
;
Finite element method
;
Longitudinal dispersivity
;
Sedimentary rock
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract Effective porosity value was analyzed from the tritium concentration of sampled groundwater using a three-dimensional groundwater-flow and advection-dispersion code based on the finite element method. The effective porosity value was about 10%. Porosity values measured from core samples were 7–15%. The groundwater flow velocity estimated from the tritium concentrations was about 1 × 10–5 cm s–1. Therefore, during the low groundwater flow velocity condition, effective porosity and porosity values were the same. At the same test site, a 0.48% effective porosity value, determined by another tracer test injecting Br– solution into the aquifer during groundwater level change, was smaller than the porosity value when the flow velocity was 1.8 × 10–2 cm s–1. Thus the effective porosity value is concluded to be due to groundwater flow velocity. The specific yield value was calculated to be 0.6% by the total volume of tunnel seepage water and the total volume of the rock unsaturated during tunnel construction. However, as pore water continued to be drained after the groundwater level change was completed, the specific yield value became larger than 0.6%. Thus specific yield value is concluded to be due to drainage time.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002540050048
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