( 2 ) statistical character and engineering control effect of short and intermittent structural plane ( iiia and iiib level ) of dam abutment has been systemically studied . and this kind of structural plane took important effect to appraise whether latent discrete boundary of massif could be formed and rock mass quality ( 2 )系统研究了坝肩短小、断续性结构面(分类中的_ a类和_ b )的统计特征及其工程控制效应,阐明了此类结构面对能否构成坝肩岩体块体的潜在分离边界以及对岩体质量的评价起着重要作用。