By doing single fracture drainage experiments , this paper has successfully presented the logarithm function relationship between ratio of drainage discharge through upward and plumb drainage hole and the ratio of their equivalent diameters . the drainage effect will be the best when the included angle between drainage hole and fracture surface is 21 ~ 36 4 、通过单裂隙排水试验，建立了倾斜孔和垂直孔的排水量之比与其交界线的等效直径比之间的自然对数关系式，排水孔排水量基本随其与裂隙面的交角减小而增大；对单组裂隙排水的初步分析表明，排水孔与裂隙面的夹角在21 ~ 36范围内排水效果最佳。
( 2 ) making use of some measure methods of field and indoor , the geostress status in the engineering rockmass has been ascertained and the systematic recognition of the geostress field in the area has been attained : the direction of a l in the area is n50 ? ~ 86 ? w , and the included angle between the direction of o , and the horizontal surface is 25 - 45 ? on the whole ( 2 )通过现场和室内测试，查明了工程区岩体的空间应力状态，获得了整个隧道工程岩体内地应力的空间发育分布规律的系统认识。研究表明，本区最大主应力_ 1的(水平投影)方向为n50 ? 86 w ，与水平面的夹角总体上介于25 - 45之间。
