万安溪面板堆石坝石料的调查与应用

Investigation on Rock Material for Wan''''anxi Concrete Face Rock-fill Dam and Its Application

Rocks nearby Wan'anxi damsite are almost sranite-porphyry. It is difficult to find out a rich quarry with thin covering layer there. Throush continuous investisation, it is discovered that there exists finegrained granite only in the side or the top marginal petrographic factes of a large volume of rock,and that there also ealsts coarse and fine grain mixed sranite only under its protection. The granite is hard and strong water-proof. Among its mineral ingredients,potassium and plagioclase account for two thirds or more. There are two sets of medium cleavages in plagioclase. The link force between the cleavages is smaller than that between its grains. This is beneficial to drill holes with a rotary-percussion drill so that the drill head would not be consumed too quickly. Rock-fill material and transition material can be obtained by millisecond blasting of the granite that is created in joint crack.