Abstract: Perilous rock is a kind of common geological disaster with great harm，which is widely distributed in the Three Gorges Reservoir area.The basic features， the damage ways and the formation mechanism of typical perilous rock were studied.It was pointed out that there were three damage types，including falling type， sliding type and dumping type；and the chain reaction had influence on the damage modes of perilous rock.There was a great difference on the strength and weathering resistance between sandstone and mudstone (shale).The mudstone (shale) was easy to become a weak base because of its low strength，its easiness to be softened and weathered.Therefore，the mudstone (shale) became concave rock cavity because it was shattered and loosened；and the upper sandstone became perilous rock.The research shows that based on the correct analysis on the formation mechanism of perilous rock，the “artificial removing + point anchoring + suspended spray anchor + active protective net” technology is adopted to control the perilous rock in such areas，and the effect is obvious.

Key words: geotechnical engineering, perilous rock, formation mechanism, governance

摘要： 危岩是三峡库区分布广、危害大的常见地质灾害类型。研究了典型危岩的基本特征、破坏方式及形成机制，指出其破坏方式有坠落式、滑塌式、倾倒式3种类型，且危岩体破坏模式中有 链式反应的影响。砂岩及泥(页)岩的强度和抗风化性能差异大，泥(页)岩因强度低、易软化、易风化而成为软弱基座，且破碎松脱之后形成凹岩腔，上部砂岩即成为危岩。研究表明：在正确 分析危岩形成机制的基础上，在此类地区采取“人工清方+点锚+挂网喷浆+主动防护网”技术对危岩进行工程治理，效果明显。

关键词: 岩土工程, 危岩, 形成机制, 治理