Abstract
Grouting is regareded as difficult to decrease the permiabilitiy of “Masa” (weathered granite) that naturaly shows low permiability. The author carried out the grouting test to these granite. That test consists mainly of the comparisom between 5 meters stage and 1 meter stage. Acoording to the test the author concluded some properties of homogeneous Masa.
1. It is able to avoid cracking of foundation that causes bad influence on improvement of permeability by selecting injection pressure of Lugeon test and grouting addequatly.
2. Water injection during Lugeon test and grouting causes microscopic fissures that results in the decrease of the stages of low Lugeon value (namely less than 1 Lu).
3. The selection of lower injection pressure of Lugeon test than that of grouting makes it possible to avoid the growth of fissures.
