炭層ボーリング中のAEと口径依存性
沿層ボーリング中のAE活動に関する研究 (第3報)
1988 年 104 巻 1210 号 p. 871-875
詳細
1988 年 104 巻 1210 号 p. 871-875
In coal mines AE method is applied to testboring in an attempt to obtain the necessary information about the stress distribution in coal seams where coal outburst might occur. AE counts are measured as the main value in AE activities. This value seems to be affected by borehole diameters. There havebeen in a state of uncertainty with regard to the relation between AE counts and borehole diameters.In order to make clear this uncertainty, six boreholes of various diameters were drilled, and duringthe drilling AE counts were measured.
As a result of this tests, AE ring down counts, (Y) during boring are related to borehole diameters (X) by the following equation: Y=2.3×10-2X22.004Theoretical formula for the relation between X and Y derived by using the probability theory agree with theexperimental result.
