In this paper are mentioned problems and measures concerned with groundwater that ensued by deep underground development.
Various issues have to be examined during projects undertaking. They are as follows :
(1) to optimize the measures against groundwater during excavation;
(2) to evaluate stabilization of excavating ground effectively;
(3) assessment on environmental impacts.
Considering these issues, projects have to be planned reasonably.
From these viewpoints, it is necessary to determine anisotropic permeabilities for optimal design of measures against groundwater. "Multi-Stage Pumping Test" is used to determine horizontal permeability, kh, and vertical permeability, kv. This test is carried out by pumping up from one section of a deep well which has several screens. Using drawdown data on multi-depth observation points, anisotropic permeabilities are obtained. A method is presented for simple analysis using data in steady state.
This test was applied to- a construction site where deep excavation planned in Tokyo.